Foretravel Motorhome Forums => Foretravel Discussions => Topic started by: Mike Leary (RIP) on March 09, 2018, 03:38:22 pm
Title: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 09, 2018, 03:38:22 pm
I've never done it, but when I go to air the tires, can I leave the coach plugged in when running the engine for air, no problems with the batteries? Here's the new gauge with a fresh coupler. A suggestion from a forum member! ^.^d Power Tank - - Powertank.com (http://www.powertank.com)
Title: Re: Airing tires from onboard hose.
Post by: jor on March 09, 2018, 03:50:29 pm
Sure. I gotta say, however, that airing up coach tires from the onboard system is a pain. I used to carry a little air compressor which makes the job a lot easier. If you haven't already done so, I would recommend you crank up your D-2 air governor to 130 psi or so. Nice air hose setup btw. jor
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 09, 2018, 03:51:14 pm
I've never done it, but when I go to air the tires, can I leave the coach plugged in when running the engine for air, no problems with the batteries? Here's the new gauge with a fresh coupler. A suggestion from a forum member! ^.^d Power Tank - - Powertank.com (http://www.powertank.com)
Yes you can, but if the tires are not really low wait until you are ready to leave so you can run the engine up to operating temp. after you leave.
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 09, 2018, 04:04:43 pm
I would recommend you crank up your D-2 air governor to 130 psi
With the new Michelins and having the coach four corner weighed, Michelin says I only need 85 front/80 rear. We'll see! ^.^d
Title: Re: Airing tires from onboard hose.
Post by: jor on March 09, 2018, 04:49:52 pm
Quote
Michelin says I only need 85 front/80 rear.
Uh, oh... Mike. Prepare yourself. I sense a barrage of tire pressure comments coming your way. This topic is second only to dumping procedures in bringing out the passion.
I've gone back and forth on this. On this rig (only 26K loaded) I too am going just a bit over the Michelin tire chart recommendation with 80 and 80. (275/80R-22.5, load range G) jor
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 09, 2018, 05:15:19 pm
Uh, oh... Mike. Prepare yourself. I sense a barrage of tire pressure comments coming your way.
Bring 'um on, John! The tires are not stock: Michelin 255/80R/22.5, a little fatter than original. In 50% traveling mode (water, fuel, propane. grey and black water) she weighs out at 8,600 front and 15,000 stern. Rides and steers perfect! If Michelin was wrong, I'd like to know! ^.^d
Title: Re: Airing tires from onboard hose.
Post by: Mike Brez on March 09, 2018, 06:03:35 pm
https://m.youtube.com/watch?v=n5fK54DKWP0
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 09, 2018, 06:46:03 pm
Pretty interesting, thanks, Mike. I agree with the air pollution and noise, I'm very carefull about that. I'm an "analog guy" I like gauges rather than readout systems. The unit I have can be used as a pressure gauge without air induction, very accurate, which is why I know she needs air, we've been sitting at the pier since November and psi loss is normal. I'm caught between a rock and a hard place as I need air but don't want to run the CAT without a load. It's dry as all get out down here, and I don't know if it will affect the engine by running it as I air-up without putting a load on.
Title: Re: Airing tires from onboard hose.
Post by: Bill & Kim on March 09, 2018, 07:55:24 pm
We ordered a Viair portable compressor (Viair 40047 400P-RV Automatic Portable Compressor Kit), from Amazon. Had been using the onboard air compressor, which took forever to air up all 6 tires... with the engine running... annoying me and probably those around me.
Had a neighbor at an RV park who used the pump on his - swore by it and aired them quickly. Simply attach it to your cars battery, start the car and start airing your tires. The car is a lot quieter, which neighbors will appreciate. I was really impressed on how quickly I could air the tires - fronts @115#, rears @ 105# (running Toyos H's)- probably took a third of the time to air 'em all.
That's a lot of air. :whistle:
Title: Re: Airing tires from onboard hose.
Post by: Ted & Karen on March 09, 2018, 08:02:27 pm
I always use my onboard compressor and run the engine at high idle so it airs up faster. I have been told it is better to use the onboard compressor because it goes through the air dryer, thus only dry air goes in the tires. I have seen some shops have air dryers on their compressors, but does the Viair or other compressor?? If not, would it be a good idea to put a dryer on?
Inquiring minds would like to know. ^.^d
Title: Re: Airing tires from onboard hose.
Post by: Bill & Kim on March 09, 2018, 08:09:55 pm
I always use my onboard compressor and run the engine at high idle so it airs up faster. I have been told it is better to use the onboard compressor because it goes through the air dryer, thus only dry air goes in the tires. I have seen some shops have air dryers on their compressors, but does the Viair or other compressor?? If not, would it be a good idea to put a dryer on?
Inquiring minds would like to know. ^.^d
Not to my knowledge, no. But seeing as how I've always aired my car & truck tires up without an air dryer, not sure how important that would be. We full-time so the coach doesn't stay stationary for long...
Maybe I should stay out west and only fill up there...? :o
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 09, 2018, 08:12:22 pm
I always use my onboard compressor and run the engine at high idle so it airs up faster. I have been told it is better to use the onboard compressor because it goes through the air dryer, thus only dry air goes in the tires. I have seen some shops have air dryers on their compressors, but does the Viair or other compressor?? If not, would it be a good idea to put a dryer on?
Inquiring minds would like to know. ^.^d
You opened up Pandora's Box. My personal experience of working as a heavy equipment mechanic for the Operating Engineers and as a truck driver for 40 years has never seen an issue with moisture in tires causing a problem. I have read on the Forum about someone posting about rust in the steel belts. I have never seen any steel belts on the inside of any of my tires. Driving my crane I have to jump curbs and run over parking lot concrete stops and still no inside damage. As the saying goes your mileage may vary.
Title: Re: Airing tires from onboard hose.
Post by: Chuck & Jeannie on March 09, 2018, 10:05:35 pm
I've never done it, but when I go to air the tires, can I leave the coach plugged in when running the engine for air, no problems with the batteries? Here's the new gauge with a fresh coupler. A suggestion from a forum member! ^.^d Power Tank - - Powertank.com (http://www.powertank.com)
Mike,
Do you have the "reversed" valve extensions on your outside dual wheels? If you don't, you should get one of the "straight in/straight out" air chucks. See the photo below. The one you want is the bottom one - makes filling the outside tires much easier.
Title: Re: Airing tires from onboard hose.
Post by: John S on March 10, 2018, 06:58:50 am
Also filling the tire is easier if you hit the brakes a few times to get the air compressor to kick in the use fast idle. I filled my Jeep tires all the time that way and needed that to top off my coach tires on my 270 and my 36 foot 320. The 42 foot took too much pressure up front so I carried a small electric compressor.
Title: Re: Airing tires from onboard hose.
Post by: Moby on March 10, 2018, 09:17:05 am
Just to inflate passion on this discussion (see what I did there?), you can always fill your tires with Nitrogen. Those in the know claim that tires do not leak down (as the rubber compounds are more resistant to Nitrogen) as fast as plain old air ad since the gas goes through some super-duper dryer theres no worry about interior corrosion. Or, are they just full of hot air?
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 10, 2018, 09:21:40 am
Just to inflate passion on this discussion (see what I did there?), you can always fill your tires with Nitrogen. Those in the know claim that tires do not leak down (as the rubber compounds are more resistant to Nitrogen) as fast as plain old air ad since the gas goes through some super-duper dryer theres no worry about interior corrosion. Or, are they just full of hot air?
Biggest advantage is the pressure stability when heated, that is why nascar uses it. After all the air is 78 % nitrogen to begin with.
Title: Re: Airing tires from onboard hose.
Post by: Chuck & Jeannie on March 10, 2018, 09:40:02 am
Our Kia Sorento supposedly came from the dealer with (extra cost dealer added accessory) nitrogen in the tires. I mean, how can you really tell if it's "genuine" nitrogen? Anyway, the dealer said I needed to ALWAYS bring the car back to the dealership to get the tire pressure adjusted, or else risk losing the "pure nitrogen" advantages. I asked what advantages? He gave me a pretty glossy booklet from the PurigeN98 company, which apparently supplies the dealer with the (money making) tire filling system. I said "Are you going to reimburse me the cost of gasoline to make the 40 mile round trip to your shop to get my tires topped off?". You know the answer to that.
But I did get some really cool BLUE valve caps out of the deal!
Also filling the tire is easier if you hit the brakes a few times to get the air compressor to kick in the use fast idle. I filled my Jeep tires all the time that way and needed that to top off my coach tires on my 270 and my 36 foot 320. The 42 foot took too much pressure up front so I carried a small electric compressor.
That's what's nice about the video I posted. You can do it outside your rv.
Title: Re: Airing tires from onboard hose.
Post by: Roger & Susan in Home2 on March 10, 2018, 10:05:03 am
I have an inline oil/water separater that I use when adding air to the tires or the level system. Works quite well. Amazon.com: TEKTON 4755 Oil/Water Separator: Home Improvement (https://amazon.com/gp/product/B001NSYV58/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
Title: Re: Airing tires from onboard hose.
Post by: Moby on March 10, 2018, 10:16:17 am
OOOHHHH! BLUE!!!!! The only way you can tell for sure is to check for the decal stuck on the inside of every tire thats nitrogen filled. Its' a certificate stating that they used 100% official Nitrogen.
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 10, 2018, 10:44:41 am
OOOHHHH! BLUE!!!!! The only way you can tell for sure is to check for the decal stuck on the inside of every tire thats nitrogen filled. Its' a certificate stating that they used 100% official Nitrogen.
Good one Moby, I think I will stay with the 78% N that's been through my dryer.
Title: Re: Airing tires from onboard hose.
Post by: folivier on March 10, 2018, 11:07:50 am
To make airing the outside duals much easier I like to have a tire shop replace the valve with a shorter one and turned so that it is not pointed toward the inside. That way it is easily accessible.
Title: Re: Airing tires from onboard hose.
Post by: Chuck & Jeannie on March 10, 2018, 11:11:05 am
To make airing the outside duals much easier I like to have a tire shop replace the valve with a shorter one and turned so that it is not pointed toward the inside. That way it is easily accessible.
Concur! Also makes it easier to install tire pressure monitor sensors. Will get our valves done that way when we get fresh tires (soon).
Title: Re: Airing tires from onboard hose.
Post by: Roger & Susan in Home2 on March 10, 2018, 11:12:40 am
I thought green caps were for nitrogen or just easier to see. I got 100 of them for $2.99 Easier to find when I drop them in the dirt
Amazon.com: Alonea 100pcs Fashion Plastic Auto Car Bike Motorcycle Truck... (https://amazon.com/Alonea-100pcs-Fashion-Plastic-Motorcycle/dp/B071FH33YG/ref=sr_1_59?s=automotive&ie=UTF8&qid=1520698220&sr=1-59&keywords=valve+stem+caps+green)
Title: Re: Airing tires from onboard hose.
Post by: Chuck & Jeannie on March 10, 2018, 11:58:05 am
To make airing the outside duals much easier I like to have a tire shop replace the valve with a shorter one and turned so that it is not pointed toward the inside. That way it is easily accessible.
Concur! Also makes it easier to install tire pressure monitor sensors. Will get our valves done that way when we get fresh tires (soon).
I want to do the same as you do. We have tire pressure monitors installed and it is not fun dealing with the valve stem pointing inward. Regarding cost: We had to replace a leaky stem on a inner tire a last November, $37. Given how critical proper tire inflation is, I'm willing to pay the $74 to make the job easier on the outer tires. (Our tires are 3 years old this coming May, lots of travel left in them. I'd like to make this change asap, if it is doable).
So has anyone actually changed their outside dual tire valve stems to point outwards?
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 10, 2018, 12:50:09 pm
I thought green caps were for nitrogen or just easier to see. I got 100 of them for $2.99 Easier to find when I drop them in the dirt
Amazon.com: Alonea 100pcs Fashion Plastic Auto Car Bike Motorcycle Truck... (https://amazon.com/Alonea-100pcs-Fashion-Plastic-Motorcycle/dp/B071FH33YG/ref=sr_1_59?s=automotive&ie=UTF8&qid=1520698220&sr=1-59&keywords=valve+stem+caps+green)
These would be easy to see also.
100x Blue ABS Wheel Tire Tyre Valve Stem Caps Dust Air Cover Screw Car Bike... (https://www.ebay.com/i/202214675719?chn=ps)
Title: Re: Airing tires from onboard hose.
Post by: Pamela & Mike on March 10, 2018, 01:00:25 pm
So has anyone actually changed their outside dual tire valve stems to point outwards?
Ours do, we did the change shortly after we got the coach due to Mike's health issues at the time and I was responsible for checking while he was broke down. As stated above it makes checking pressure and installing TPS a lot easer to do.
Pamela & Mike
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 10, 2018, 01:04:16 pm
The long fill tubes has caused leaks for me in use from centrifical forces bending the tube and causing leaks at the gasket.
I use supported extensions on the inside duals and fill through metal caps on all tires.
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 10, 2018, 01:50:58 pm
Had been using the onboard air compressor, which took forever to air up all 6 tires... with the engine running... annoying me and probably those around me.
Time, noise and air pollution are of concern to me, as well. When you say "forever", how long is that in Forum terms? Those little compressors are spendy, but if it's a "six pack job" to get 10/15 lbs in all tires, even though my storage space is shrinking, I might consider one. ^.^d
Title: Re: Airing tires from onboard hose.
Post by: Travelin' Man (RIP) on March 10, 2018, 02:40:25 pm
Simply attach it to your cars battery, start the car and start airing your tires.
B&K, How much power cord and air line come with the Viair 40047 400P-RV?
And what about this one for less dough? Amazon.com: VIAIR 400P Portable Compressor: Automotive (https://www.amazon.com/VIAIR-40043-400P-Portable-Compressor/dp/B000X9AXR8/ref=sr_1_2?s=automotive&ie=UTF8&qid=1520711546&sr=1-2&keywords=Viair+40047+400P-RV)
Title: Re: Airing tires from onboard hose.
Post by: Bill & Kim on March 10, 2018, 03:06:27 pm
Time, noise and air pollution are of concern to me, as well. When you say "forever", how long is that in Forum terms? Those little compressors are spendy, but if it's a "six pack job" to get 10/15 lbs in all tires, even though my storage space is shrinking, I might consider one. ^.^d
Took me about 2oz. of scotch... much less than a 6-pack. Probably 20 mins. overall.
B&K, How much power cord and air line come with the Viair 40047 400P-RV?
The power cord (with two clips for battery terminal connection), is 8', air hose is 60' (in two coiled halves). The tire inflation gauge can inflate to 130# - very handy. The pump has 150# max pressure.
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 10, 2018, 05:04:27 pm
By maxing the D2 air controller valve to the 110/130 setting the air brakes stop the coach much better and the tires on mine at 87/97 psi fill quickly with the motor at fast idle. The manual release of air during the process that was posted works great to kick on the air compressor and to have it build up the air to its 130 top where you can hear the spitter pop off.
Title: Re: Airing tires from onboard hose.
Post by: Pamela & Mike on March 10, 2018, 06:03:30 pm
And what about this one for less dough? Amazon.com: VIAIR 400P Portable Compressor: Automotive (https://www.amazon.com/VIAIR-40043-400P-Portable-Compressor/dp/B000X9AXR8/ref=sr_1_2?s=automotive&ie=UTF8&qid=1520711546&sr=1-2&keywords=Viair+40047+400P-RV)
We went with the 450C due to the duty cycle. Yes more $ but well worth it. Shop around as you can find them on sale if you are not in a rush. Ours has about a 15' cord and we have 1 of the spring hoses which is plenty to reach around the coach when we hook to our house batteries.
Pamela & Mike
Title: Re: Airing tires from onboard hose.
Post by: Carol & Scott on March 10, 2018, 06:14:30 pm
This thread sure has moved along -
We have been carrying a small dual tank air compressor around for a while now. Coach, Jeep, bicycle tires and blowing air at what I want when. Much easier since we have been caretaking our 42 and have a cavern in our main bay. :D
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 10, 2018, 06:44:43 pm
Not really, Scott.. Good information has been around the Forum for years, but the misinformation still abounds: For example, this thread:
Nitrogen in tires (http://www.foreforums.com/index.php?topic=20054.msg144512#msg144512)
All of the posts are easily discovered through the Forum Search Tool, but for the benefit of newbies: Just a reminder that the realities of physics and chemistry do not go away because someone pooh/poohs them, claims they have never witnessed them or has otherwise advised you to ignore them.
Do not even remotely consider putting un-dried air in your tires on a motorcoach! The tires already have enough lifetime challenges to deal with.
If we used our coaches daily, the tires would have far fewer challenges, but we don't drive them daily, so don't put "wet" air in them and make things worse. Idle coaches don't maintain a good distribution of the rubber "lubricant" compounds that are infused during the manufacturing process to help with elasticity, the lowering of permeability and providing more years of tire health and safety. Long term parking, particularly at less than sidewall rated pressures, develops "weak lubricant microstructure spots' that are more prone to "wet" air internal permeability damage and Ozone/UV external damage (external surface checking and cracking).
The argument that air "contains 78% N2, so I'm already covered" defies common sense as well as chemical reaction reality. 78% Pure N2 doesn't inert or protect anything. 95 to 98% pure N2 does. It's the 1 to 2% water vapor plus 20(+)% Oxygen that has been pumped into the tire that causes all of the harm inside a tire. The vapor condenses to a liquid at low temperatures but becomes a greatly expanded gas when at elevated temperatures. Thus the rust and corrosion (oxidation-reduction) effects when a tire is cool and then an overly exaggerated tire pressure fluctuation when the tire is hot, going down the road.
Just because someone hasn't seen rusted cords after a tire failure occurs, does not mean that the laws of nature are going to change or that oxidation-reduction chemical reactions will cease to occur. Water in a tire plus metal in the cords and in the wheel rims, means that the metals will deteriorate, through oxidation-reduction chemical reactions [rust, or corrosion in the case of Aluminum], at the rate that the laws of of physics and nature dictate, whether your advisor has witnessed it or not. Variables such as the highly important brand quality of your tire, the frequency of use of your coach, the humidity of compressor intake air, the proximity of tire use to design limits, the cord and wheel material type, the outside environment temperatures, the % moisture content in the tire, the lifetime inventory of road hazard damages to the cords and internal liner, and many others, all combine to determine actual failures. But if one can put a dry gas in the tire, eliminating all but a tiny fraction of the oxygen and water, a high percentage of the variables of concern will be all but eliminated.
If you have air and an air dryer on your coach, and you have maintained it properly (meaning there is no vapor/mist when you "blow-down-check" the wet tank), then that air is probably of the highest quality and the most easily available air that you will ever find. Increase the D-2 setting or connect your air hose directly to the D-2, if you want to increase the air hose pressure to shorten the duration of your tire "air-up" process.
Most tire service centers, all coin operated air stations, most of the advice you see here about small auxiliary air compressors, (depending upon local humidity) pump concentrated moisture forward into your tires and totally avoid common sense and the laws of physics/chemistry.
Water freezes at 32 degrees F decreasing.
Water condenses (out of the water vapor) at temperatures higher than 32 degrees F.
Compressing air concentrates the % water content in the compressor effluent.
In-line mechanical filters on an aux compressor, remove particulate contaminants, but only an unspecified small fraction of the total entrained water concentration (mostly due to the elevated temperature of the gas).
Our coach air dryers compensate for that through the use of a desiccant. Industrial applications have elaborate chillers and elaborate piping lines to cool the compressed air before the effluent reaches any desiccants. If inexpensive in-line mechanical filters were capable of overcoming the laws of physics and thermodynamics, believe me they would use them and escape the high costs.
Condensed water, sitting inside a tire that is pressurized with normally occurring free oxygen, will be pressed into the rubber and cords (under a microscope. the rubber looks like strings of spaghetti that are glued together; i.e. - the rubber is somewhat permeable and a 1 to 2.5% volume permeability/month is normal). The water/Oxygen will inevitably find every possible way to permeate the tire carcass and that leads to the oxidation-reduction of the metal cords. The water absorbed may also freeze and expand beyond the elastic restoration properties of the rubber substructure. That's why airlines and military aircraft mandate the use of a dry gas that will displace and not absorb moisture (Nitrogen).
Also, driving a tire down the road, with a chunk of ice in it before the ice melts, evaporates and turns to water vapor, will open up new microscopic ways for water to find the cords.
If you don't have air on your coach, or you don't have the patience to wait for the "low driving head" of the air system to air up tires, what are the reasonable options? Remember you have to eliminate water, or oxygen, or both is even better.
Pure Nitrogen and Carbon Dioxide are colorless, odorless, inert, non-toxic, non-corrosive, non-flammable gases.
Pure Nitrogen is less expensive to produce, but requires a large container for it to be stored as a compressed gas at normal human environment temperatures. Pure Carbon Dioxide is more expensive to produce but can be stored as a liquid, which overall, makes it much more portable and affordable on a motorcoach. On average, my 10# PowerTank aluminum bottle costs me less than $20/year to use (car, car hauler & boat trailers, 8 coach tires, golf cart and bicycles plus neighbors). Bicycles have the idiosyncrasy of requiring careful choice of inner tubes because many bicycle inner tubes are CO2 permeable (due to a lower grade rubber). Unlike a N2 tank of compressed gas, the PowerTank is always at 200 psig until all of the liquid is exhausted. It runs a 1/2 inch power tool with ease, weighs less than 25# when full and is easily portable.
CO2 PowerTanks are often available on eBay and Craig's List at reduced prices. I paid $300 for my 10# tank with a high flow regulator, a 1/2 inch drive Ingersoll Rand "air" tool, a full set of gauges, fittings, full size storage bag and a fresh bottle certification (good for 10 years IIRC).
Apples to Apples comparison and common sense dictate that a $200(+) aux air compressor pumping wet air into coach tires is less desirable than a $300 to $500 (or even full price - $600) CO2 PowerTank option.
HTH with all of the misinformation, Neal
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 10, 2018, 09:12:14 pm
I was an under experienced maintenance guy ten years ago in an electronic chip factory in our area.
We had a giant tank of nitrogen filled weekly with a semi full of gas weekly.
After that the nitrogen went through one of two ingersol rand commercial $10k refrigerated compressor nitrogen dryers..
Neal post is exactly what I have seen personally and heard and read myself.
Never put water or vapor in your tires. I have a 2,600 psi large air gas nitrogen tank here for everything.
The volume needed for rv tires would run the tank down quickly. I use two of the power tank guys tire fillers expensive ends. Best quality available normally.
Neal just motivated me to get a CO2 tank as the volume for a small tank is ten times my big nitrogen tank.
Thanks to Neal for explaining in detail what I have seen myself. I told customers in the 80's that the water vapor was being driven into the tires. Seems I was correct.
Thanks Neal
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 10, 2018, 09:14:58 pm
I have Googled for tire damage from moisture in a tire for the last hour. The only thing that comes up more corrosion on the wheel and tire sensors. I even searched images. Read the bottom line from the Rubber Manufacturers Association . I know CO2 and Nitrogen are more desirable. But show me a picture of a rusting steel cord inside a tire that doesn't already have too much damage externally to be safe and I will eat my words.
Should I Use Nitrogen Instead of Regular Air in My Tires? | News | Cars.com (https://www.cars.com/articles/should-i-use-nitrogen-instead-of-regular-air-in-my-tires-1420682864256/)
Title: Re: Airing tires from onboard hose.
Post by: Tim Fiedler on March 10, 2018, 09:21:17 pm
Wish I had saved the pictures from my left front blow out. Michelin, 8 years old. No visible damage, Steel in carcass all showed extensive rust, failure happened on cool tire in AM, with proper inflation. Wet air not good for my tires, but as always, do what makes you happy
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 10, 2018, 09:45:53 pm
I'll take your word for it Tim. I have had several front tire blowouts that didn't show corrosion on the steel cords. I thought that was a good indication of what is going on inside them. I guess I was wrong.
Title: Re: Airing tires from onboard hose.
Post by: Old phart phred on March 10, 2018, 09:52:23 pm
Interesting valid points Neal, which some I did not think about much, i agree condensate freezing is bad news. I don't have a moelire (misspelled) chart handy to check freeze point or condensation point at 100 psi. But I did look one-time at the PT chart to see when droplets expand to steam @ 100 psi and IRC correctly the tire was already toast at that point. Once oxygen is consumed during the oxyigination process it's gone. Fire sprinkler piping relies on this fact to keep from rusting thru while dormant and filled with water for 20 years or more. Very good info Neal.
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 10, 2018, 10:15:27 pm
I had many shredded coach tires on my Foretravel lot as sales manager in ca from 1986 to 1989. All showed rusty steel cords.
Tell me why I would lie about such a thing? Can still see this in my mind like yesterday.
I have posted here many times about this,
Probably why Foretravel equipped almost all l of our coaches with a dry air outlet.
Constant use may flex the tires enough to probably release the agent that permeates the carcass for flex and to lessen the water vapor travel through the carcass.
Title: Re: Airing tires from onboard hose.
Post by: Neal Pillsbury on March 10, 2018, 11:12:47 pm
I have Googled for tire damage from moisture in a tire for the last hour. The only thing that comes up more corrosion on the wheel and tire sensors. I even searched images. Read the bottom line from the Rubber Manufacturers Association . I know CO2 and Nitrogen are more desirable. But show me a picture of a rusting steel cord inside a tire that doesn't already have too much damage externally to be safe and I will eat my words.
OK
Would an article out of a well regarded trucking magazine (Overdriveonline magazine) and the picture of a truck tire failure caused by the breach of the tire's inner liner material which resulted in inflation air laden with moisture resulting in rusted tire cords failure be satisfactory?
The article focuses on an improper rope repair, stating: "A rope repair is a simple way to plug a puncture from the outside, but it often causes air to penetrate the belts, pushing them apart. Merely (rope) plugging a hole can also allow moisture from inflation air to get into the cords, and corrode them, creating a catastrophic failure later."
What is important is that it doesn't matter whether it is the result of an improper rope plug repair or some other permeation or breach of a corded tire inner liner. If a tire's inner liner is breached, moisture and oxygen will permeate the breach, infiltrate the area around the cord, break the rubber bonding with the metal cords, suffer oxidation reduction (rust or corrosion) and the tire will overheat and fail. The photo provides the documentary evidence that physics and chemistry march on regardless what some of us would rather believe.
HTH, Neal
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 10, 2018, 11:34:46 pm
Neal, I am aware of the damage caused by punctures breaching the liner. I only repair with a patch on the inside and realize that external moisture is going to occur and the steel is compromised once that has happened. I consider them unsafe and would not run it on a front tire. Because I have eight on the rear I move it there. I believe what Tim said, and even though I believed what was in the air of the tire could not penetrate the inner liner without external damage I will cede this argument.
Title: Re: Airing tires from onboard hose.
Post by: Tim Fiedler on March 10, 2018, 11:51:53 pm
the inside of a michelin has cords steel cables imbedded in the rubber that run from bead to bead. On may tire that blew -many of them were exposed after the blow out. While the event could have caused many of them to fail, enough failed on a 55 degree day, a tire whose inflation had been checked not 15 minutes earlier (110 psi) going 55 MPH or so on a two lane road not 10 minutes into the start of the trip.
all of the steel from inside the carcass showed signs of severe rust, many seemed to be less than 50% of original diameter by my estimate
8 year old tire
no special precaution re where air was added or moisture content of air tire sat 6 months of the year in FL while my Mom stayed in coach
As previously documented, damage to coach in excess of $6K (Extreme fixed, insurance paid)
I do believe that moisture can and does permeate the rubber and was the causative factor in this blow out, aided by the advanced age of the tire, sitting stationary for long periods and no real effort to reduce the moisture inside the tire - probably a worse case scenario
don't think if you had dismounted the tire and inspected this issue would have shown up in a visual inspection, even if you spent the money to bother to do it.
Tim Fiedler
Sure Start Soft Start (http://www.gen-pro.biz)
TCER Direct (http://www.tcerdirect.com) generator-gas-prod (http://www.generatorgasproducts.com) 630 240-9139 Gen-Pro
Title: Re: Airing tires from onboard hose.
Post by: Neal Pillsbury on March 10, 2018, 11:58:57 pm
..........................I don't have a moelire (misspelled) chart handy to check freeze point or condensation point at 100 psi. But I did look one-time at the PT chart to see when droplets expand to steam @ 100 psi and IRC correctly the tire was already toast at that point............................
Phred, You don't need to go find your Mollier Diagram (Steam Tables). People are often confused about the difference between water vapor and steam. Water vapor is just water droplets suspended in air (water/vapor mixture). Fog and clouds are visible water vapor. Steam is water that has been elevated to a high enough temperature that, for the given surrounding pressure, the water behaves as a true gas, instead of as a subcooled liquid (water) or as a water/vapor mixture. Once the water becomes steam, it is a superheated vapor. Water at 100 psig, at the temperatures that our tires run, is nowhere near superheated vapor or steam.. HTH, Neal
Title: Re: Airing tires from onboard hose.
Post by: ltg on March 11, 2018, 12:25:53 am
I am not arguing that dry air is not the best way to air up tires. However, I would like to point out that in the article, "Seven Tire Killers", the type of air used in inflation was not one of the seven listed. And, it was not something listed in the "Other Deadly Tire Issues". It was only mentioned as part of a problem with tire repairs.
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 11, 2018, 10:54:26 am
Tim the hidden rusty belts is what my shredded tires showed also, And maybe a little gold color discoloration on the intact parts of the inside rubber liner .
As you said lots of steel missing. Ugly. Without over playing this even more the correct comment for what I saw was scary,
If you run std air the 5 years change out might be a good idea. Trucker will put them on a trailer and run them out quickly.
Michelin guarantees 7 years, three retreads and or 700,000 miles on a Xza-3+ when run through their commercial recapper program for OTR truckers so they think with regular inspection during the process that their tires will last that long.
MAJOR DIFFERENCE the flex in constant use releases the agent(s) in the tires to allow this life.
Title: Re: Airing tires from onboard hose.
Post by: Neal Pillsbury on March 11, 2018, 01:00:57 pm
I am not arguing that dry air is not the best way to air up tires. However, I would like to point out that in the article, "Seven Tire Killers", the type of air used in inflation was not one of the seven listed. And, it was not something listed in the "Other Deadly Tire Issues". It was only mentioned as part of a problem with tire repairs.
Larry,
I used to run into this problem often, doing Root Cause Analyses. The focus was always on finding and correcting the most important of the problems and contributing factors.
So Larry, what is your take on the root cause of that tire failure? Was it the improper repair that caused the failure? If you are solely focused on and only consider the literal wording of the article, was the improper repair the true root cause?.................if it was the true root cause, the tire should have blown out as soon as it was aired up.
If I were doing a Root Cause Analysis, I wouldn't stop with the author's literal wording. I would want to know why so many cords showed extensive rusting. I would want to know, how did the moisture get into the tire, did the tire have a long slow leak history (water doesn't leak in if air is leaking out), how long since the rope plug repair was done and how much air had been made up and from where and how was it dried, if at all? What knowledge level existed in the tech? In the Owner? What was the Tire Service air system design and actual implementation? What was the post-repair operating/corrective/preventative/predictive maintenance history of the tire and can we discover the reason why so many belt cords show extensive rust? Was it even feasible for one botched plug repair to affect such a large area of cordage?
The repair may well have been a large contributing factor, but I bet that there were several other strong contributing factors. One has to find as many of the contributing factors as possible and then take them away, one at time and ask, "Would this blowout have occurred if I take this factor away?" Without going though those kinds of steps for this tire failure, I wouldn't feel comfortable stating that the improper rope plug repair was the root cause.
I would bet dollars to donuts, though, that the root cause was rusted metal cords. In order to have rust, one must have metal, moisture and oxygen. In order to have that amount of rusted cords, the inner tire membrane had to be breeched and NOW we get to the improperly sealed rope plug repair. But we also, probably, get to a bunch of human errors. People that could or should have known better than to put moisture laden air into a heavy duty, high mileage tire. Looking at basics, we usually can't avoid metal cord layers, we can choose high quality design and construction tires, we can exclude moisture and it is possible to exclude oxygen by using an inert gas. By excluding moisture and oxygen, it is also possible that the blowout could have been prevented forever. The inner membranes are very thin and I think that many get breeched from road hazards, casting flaws that age, etc. But it's also possible that external wicking along the rope plug may have occurred, if the pressure containment had remained inboard of the metal cords. Without accurate Root cause Analysis, we don't learn.
The takeaway is that just because somebody labels "improper repair as one of the top seven tire killers", it does not make it so, especially when the description talks as much about moisture intrusion and resealing of inner liner breeches as it does about examples of "improper repairs".
But the description is one of the reasons that I thought this article was especially pertinent to Craneman's concern, in that he said that he had never seen moisture intrusion and rusting of metal cords, in his experience, and could find no examples or pictures of such on the internet.
It is easy to become tied up in just accepting what someone has said and not learning valuable lessons when the lessons are right there in front of us. So we repeat history instead of learning and improving.
HTH, Neal
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 11, 2018, 01:13:39 pm
Just to show my observations I will cut open one of the tires I changed out on my crane 2 weeks ago. Date coded 2012 well worn and has climbed many concrete barriers. Will post pictures even if the cords are rusted up.
Title: Re: Airing tires from onboard hose.
Post by: ltg on March 11, 2018, 01:25:27 pm
Neal, I agree that the cause was rusted metal cords. However, there is a considerable amount of literature that suggest the cause of rusted metal cords is moisture contamination from the manufacturing process. I cannot find the same level of literature that suggest that rusted metal cords are a result of airing up tires.
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 11, 2018, 01:26:42 pm
This came with the Coach, not needed anymore, but I'm keeping it. Look where it was made! ^.^d
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 11, 2018, 02:07:04 pm
Big difference probably internally and externally is the apparent designed in release of agents that in use on a truck driven continuously or a crane driven daily are to keep the tire carcass flexible and probably keep the water vapor from transpiring through the tires carcass.
Our lack of heavy use probably negates the built in protections that 99% of the users would generate.
On third thought if you are not going to put in dry anything maybe a non steel belted tire might be an option for you.
Coach came with steel Michelin's and a dry air source on board probably for a reason
My x Foretravel line mechanic was the go to guy at a local high volume trailer dealer and he quit as he was dong PDI's on trailers and the dealer was not replacing the used trailer tires over five years old which he thought was unsafe.
No dry air. Lots of heat. Overloading. Under inflation in storage.
The power tank guys website mentions not reinflating any tire locally that was down to 80% of rated pressure. Take to a pro place that has a cage to inflate the tire in and contain any debris if it fails.
No wonder the trailer tires fail alot on the side of the road.
So it seems because of our limited use that the dry anything becomes more important.
I doubt if the tire makers are going to spend the money and testing to change their over the road truck tires design for rv use
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 11, 2018, 02:35:28 pm
Haven't smelled that much burning rubber since I was at the drags. Tire history: manufactured in 2012 the week is illegible, Dynatrax made in china. I have always mounted my own tires since 1978 and use Dawn and water to lubricate to break down and install. Probably 1/8 cup gets in the tire as I use a sprayer not a brush or rag. I posted with my experience and am not infallible. I ground down until I could see the cords and knowing the grinder would remove any rust if it was present, used a razor knife to cut a section away. This tire has no sign of corrosion, I will admit it is the only one I have broke down and inspected the steel, and it is the last, everything including me has burnt rubber shards stuck on it.
When I quoted Kim I stated he had opened up Pandora's Box, got that right.
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 11, 2018, 02:39:16 pm
I'm going to wait until we leave to the north in June to air the tires with the on-board hose. She's got 70psi now, they look fine. That little stool will be handy! ^.^d
Title: Re: Airing tires from onboard hose.
Post by: Moby on March 11, 2018, 02:46:43 pm
When I quoted Kim I stated he had opened up Pandora's Box, got that right.
Kinda like the "hooking your generator to your house" discussion.
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 11, 2018, 02:51:21 pm
Yep!
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 11, 2018, 03:00:56 pm
My large volume local so cal FMCA tire dealer(Parkhouse Tire) and I both use and used MYLER's tire mounting lubricant. Not the Michelin tiger stuff.
No water induced into the tire from the mounting lube.
Black thin grease type stuff.
Are all theses steps necessary? Correct mounting lube. Dry something. Exact tire pressures?
It's only your safety. Wanna bet Foretravels Michelin tire supplier or it's guys used non water based mounting lube?
Safer to be paranoid
I wonder if Neal could help me figure out how much of a large nitrogen tank it would consume to deflate 6 tires and refill them? 2,600 psi.
$45 dollars to refill the tank. Might be worth it
Title: Re: Airing tires from onboard hose.
Post by: ltg on March 11, 2018, 03:18:23 pm
It was mentioned early on in this thread that some use the onboard air compressor to air up their tires because the air goes through the air dryer. If when using the onboard air compressor the air is coming directly from the air dryer that would be the case. But if the air is coming from the air tanks, that may not be the case. On some model Foretravels, there is a 12 volt air compressor. And on some models that air compressor can fill the main tanks. And, on some models that 12 volt air compressor does not have an air dryer. So the tanks may not have completey moisture free air.
Title: Re: Airing tires from onboard hose.
Post by: Jim Frerichs on March 11, 2018, 08:05:38 pm
Hi Guys,
Too bad Corrosion X is so slick - otherwise it might be a good rust inhibitor to be used during tire fabrication.
Jim
2002 U320
Title: Re: Airing tires from onboard hose.
Post by: John44 on March 12, 2018, 09:46:12 am
Observations,could the steel in the tires have moisture in it when assembled? If I had nitrogen in my tires a way for ME to put nitrogen in would be a must have. Seems the older coaches have problems with the 12 volt air compressor and moisture,why could'nt we fit a second dryer the same as the main one just for this air compressor,has anyone tried that?Surely it would last longer then the dissacant in the small dryer.
Title: Re: Airing tires from onboard hose.
Post by: Mike J on March 12, 2018, 10:17:19 am
It was mentioned early on in this thread that some use the on-board air compressor to air up their tires because the air goes through the air dryer. If when using the on-board air compressor the air is coming directly from the air dryer that would be the case. But if the air is coming from the air tanks, that may not be the case. On some model Foretravels, there is a 12 volt air compressor. And on some models that air compressor can fill the main tanks. And, on some models that 12 volt air compressor does not have an air dryer. So the tanks may not have completely moisture free air.
I'm new and learning. Stepping out into the deep water of this discussion with some newbie trepidation. My personal experience is that the 12v compressor isn't made for airing the tires. My chassis guy confirms this as do some forum members. (12v compressor only good to maintain coach level). We always add air to the tires when needed from the air chuck installed OEM. Have always assumed that is dry air from engine air compressor. No moisture period.
Some coaches yes, some not. Clarification anyone? Piping diagram/routing? Coach model numbers too if you have them.
Bottom line?.... Where does the air for the OEM FT air chuck come from?
Much appreciated.
Title: Re: Airing tires from onboard hose.
Post by: Chuck & Jeannie on March 12, 2018, 10:27:01 am
Title: Re: Airing tires from onboard hose.
Post by: John44 on March 12, 2018, 10:50:15 am
On the 96 u270 it comes from the engine air compressor,dry air.You have to fill your tire with the engine running to get the air pressure so unless I'm missing something which tank it comes from does'nt matter,it's air that has gone thru the dryer.
Title: Re: Airing tires from onboard hose.
Post by: jcus on March 12, 2018, 10:57:46 am
On the 96 u270 it comes from the engine air compressor,dry air.You have to fill your tire with the engine running to get the air pressure so unless I'm missing something which tank it comes from does'nt matter,it's air that has gone thru the dryer.
On Mikes coach, air can go to tanks from small air compressor which may or may not have an air dryer. He can use the 12 v compressor to fill tanks via a switch and solenoid valve but probably only to about 90 psi.
Title: Re: Airing tires from onboard hose.
Post by: Doug W. on March 12, 2018, 11:01:00 am
I wonder if Neal could help me figure out how much of a large nitrogen tank it would consume to deflate 6 tires and refill them? 2,600 psi.
$45 dollars to refill the tank. Might be worth it
Been using this product in my Toyo tires, never had air loss over time and no added weight to balance steer tires. Takes about 20 oz. per our size tires. Alternative to nitrogen, said to be more effective with many more benefits.
Tire Life® Video « Fuller Bros. (http://www.fullerbros.com/tire-life-movie/)
Title: Re: Airing tires from onboard hose.
Post by: ltg on March 12, 2018, 11:28:37 am
On the 96 u270 it comes from the engine air compressor,dry air.You have to fill your tire with the engine running to get the air pressure so unless I'm missing something which tank it comes from does'nt matter,it's air that has gone thru the dryer.
Does the manual that came with your coach suggest that you drain the moisture from you tanks on a daily or weekly schedule?
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on March 12, 2018, 12:08:58 pm
I always assumed my air hose was interconnected to the dryer, but now everyone has me wondering. Maybe PO Brett knows, except I think he and Dianne took the sailboat and sailed away off the forum! ;)
Title: Re: Airing tires from onboard hose.
Post by: jcus on March 12, 2018, 12:14:40 pm
I always assumed my air hose was interconnected to the dryer, but now everyone has me wondering. Maybe PO Brett knows, except I think he and Dianne took the sailboat and sailed away off the forum! ;)
Compressor loads up, pushes air through air dryer to wet tank. Air hose attached to wet tank.
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 12, 2018, 01:09:22 pm
So the "wet" tank is simply a term for a brake systems pressure storage tank. Whether or not it has run through a dryer.
I think bringing this info out in the forum is a necessary good thing.
The over inflation of the tires maybe should be researched and posted also?
Batteries, dry air, correct inflation for the actual loads on each tire were my main talking points with owners when I was sales manager of Foretravels Irvine, ca store in the 80's.
Title: Re: Airing tires from onboard hose.
Post by: Mike J on March 12, 2018, 01:11:21 pm
Thanks to everyone for putting air into my tire/rubber/steel cord education. I'm learning a lot. The forum is surely where the rubber meets the road!
This is what I think we have for dry air to fill my tires. Based on what I see in the 2003 air diagram and our 2002 U270. May not specifically apply to your coach. Please correct me if in error or confirm my assumptions if you wish.
1. All air supplied by the engine compressor is dried.
2. The switch (we have one) at dash in retarder consol, opens solenoid allowing un-dried air from the 12v compressor directly into the wet tank. When preparing to depart a campground and we find our air system is depleted, FT has provided me a choice: Either idle engine long enough to build air pressure or use the 12v compressor to pressurize the tanks, (albeit very slowly) and thereby keep the neighbors happy by not running the engine. The down side of being quiet is slow pressure build time and introducing contaminated un-dried air into the wet tank.
3. The air chuck can receive un-dried air directly from the 12v compressor. It can also receive dry air from the engine compressor via the front brake tank. (The 12v compressor should not be used to air the coach tires as it does not supply enough psi and volume and doing so would/could introduce moisture into the tires).
4. If parked, engine off, and keeping coach level with the 12v compressor, the air going to airbags is undried.
5. Is the pressure required to inflate the airbags for travel/leveling below the 65 psi threshold of the tank check valves. This would mean no contaminated un-dried air from the 12v compressor can enter the brake tanks UNLESS, the dash switch in #2 above has opened the solenoid at some time allowing 12v compressor air into the wet tank and subsequently the fr/rr brake tanks.
6. My choice if all the above is correct: Leave solenoid switch at dash off. Only use the 12v compressor to keep coach level while parked. Use the engine to build tank air pressure and fill tires. Get to know my park neighbors and if possible, don't leave our campsite before they have had their cup of coffee in the morning.
Thanks, Mike J
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 12, 2018, 01:26:30 pm
Mike was this switch allowing non dry air a model wide std install put in new or a owners mod or a specific coach only item?
My first thought was to actually find all the chassis side leaks versus run non dry air into the coach.
Knock wood my x Foretravel line mechanic found all of our coaches leaks and it has not moved from whatever level it is at for 6 years. I turn off the hwh panel after leveling
Title: Re: Airing tires from onboard hose.
Post by: Mike J on March 12, 2018, 01:33:06 pm
Been using this product in my Toyo tires, never had air loss over time and no added weight to balance steer tires. Takes about 20 oz. per our size tires. Alternative to nitrogen, said to be more effective with many more benefits.
Tire Life® Video « Fuller Bros. (http://www.fullerbros.com/tire-life-movie/)
Interesting product Doug, Do you have tire pressure sensors? Wondering if this stuff would mess with them.
Thanks, Mike J
Title: Re: Airing tires from onboard hose.
Post by: Doug W. on March 12, 2018, 01:49:01 pm
Interesting product Doug, Do you have tire pressure sensors? Wondering if this stuff would mess with them.
Thanks, Mike J
Mike, no l do not use tire sensors. Yes my thoughts it would mess with them.... maybe depends on which type of sensor?
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 12, 2018, 02:37:50 pm
Interesting that in the products description they mention it's addressing several moisture issues posted here.
Would seem that dry air would be less messy.
Title: Re: Airing tires from onboard hose.
Post by: Mike J on March 12, 2018, 04:40:55 pm
Hi Doug,
I have the TST TPMS. Have to check with them about using this inside the tires.
The video/write up on product you're using is interesting and possible solution? Given it appears the blowouts that have been discussed here thus far seem to show rusted steel cords in the carcasses. I would think anything that helps seal the tire inner surface would be helpful. At least that is one feature they claim and is how they are selling it.
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 12, 2018, 04:42:55 pm
Title: Re: Airing tires from onboard hose.
Post by: craneman on March 12, 2018, 05:14:27 pm
The biggest advantage of the product is the prevention of rust on the wheels of heavy equipment and the labor it saves. Wish they had this product when I was a heavy equipment mech. in the Operating Engineers. It would sometimes take 4 hours to get a tire off of a scraper because of rust built up on the wheel.
Title: Re: Airing tires from onboard hose.
Post by: Chuck & Jeannie on March 12, 2018, 06:34:17 pm
.......................Please correct me if in error or confirm my assumptions if you wish...........................
Mike J, I have a couple of comments regarding your assumptions. For convenience sake, I've just added them into your posting, using a different color font.
Thanks to everyone for putting air into my tire/rubber/steel cord education. I'm learning a lot. The forum is surely where the rubber meets the road!
This is what I think we have for dry air to fill my tires. Based on what I see in the 2003 air diagram and our 2002 U270. May not specifically apply to your coach. Please correct me if in error or confirm my assumptions if you wish.
1. All air supplied by the engine compressor is dried. Yes, but only if your air dryer has been properly maintained and the desiccant has not outlived its function.
2. The switch (we have one) at dash in retarder console, opens solenoid allowing un-dried air from the 12v compressor directly into the wet tank. When preparing to depart a campground and we find our air system is depleted, FT has provided me a choice: Either idle engine long enough to build air pressure or use the 12v compressor to pressurize the tanks, (albeit very slowly) and thereby keep the neighbors happy by not running the engine. The down side of being quiet is slow pressure build time and introducing contaminated un-dried air into the wet tank. In model year 2002, FT started using the Thomas TA4101 12Vdc, 1/3 HP, 100 psig (max.), auxiliary air compressor. I believe that is what you should find in your coach. The reason they did this was due to the need for a higher duty rating and a more robust compressor when slides were added to the coaches. The older coaches had a less robust, lesser duty rating compressor (brands and models escape me at the moment). The 12 Vdc compressors have always been there as an HWH air leveling system maintenance unit, and the dry air needs were of less concern since they fed aluminum blocks and rubber air bags. With the advent of slides, air demands increased and beyond the compressor changes, Wilkerson filtration, including desiccants, and aux. air storage tanks were added, across all model levels, I believe. The spec sheets are not exact, but I believe the notation "Auxiliary 12 Volt Air Compressor" on models U270 through U320, starting in 2002 and beyond, signifies the Thomas TA4101 plus filtration use.
"Properly maintained", again; If your Wilkerson filtration is being maintained properly, you will never have moisture added to your tires or tanks from a 100 psig, Thomas 12Vdc aux air compressor. The problem is that people don't maintain them properly.
In the PDI (pre-delivery-inspection) that I performed on our current (SPEC) coach, I found the aux compressor cycling frequently and water, a large amount of water, in my "slide (even though I don't have any slides) aux air tank". That was because there were numerous air leaks throughout the coach, the aux. air compressor desiccant was long exhausted, the "slide aux. tank" had not been blown down (blowdown fittings are not extended out to wheel well access on 2002's), etc. etc. The other tanks were fine, so apparently the PO did not use the left dash "air tank" switch frequently (because it passes aux. compressor effluent to the wet tank as well as the front, rear and aux air tanks). Besides many air leak repairs, I had to take down the aux tank and have it refurbished, I had to rebuild the Thomas compressor and the Wilkerson filtration system had to be replaced.
3. The air chuck can receive un-dried air directly from the 12v compressor. No. Your air chuck air should be from a dry source, if your aux air filtration (desiccant) is being maintained. It can also receive dry air from the engine compressor via the front brake tank. (The 12v compressor should not be used to air the coach tires as it does not supply enough psi and volume and doing so would/could introduce moisture into the tires).
4. If parked, engine off, and keeping coach level with the 12v compressor, the air going to airbags is undried Your HWH air should be from the Aux Tank which is a dry source, if your main and aux air filtration (desiccant) is being maintained properly.
5. Is the pressure required to inflate the airbags for travel/leveling below the 65 psi threshold of the tank check valves. This would mean no contaminated un-dried air from the 12v compressor can enter the brake tanks UNLESS, the dash switch in #2 above has opened the solenoid at some time allowing 12v compressor air into the wet tank and subsequently the fr/rr brake tanks.
6. My choice if all the above is correct: Leave solenoid switch at dash off. Only use the 12v compressor to keep coach level while parked. Use the engine to build tank air pressure and fill tires. Get to know my park neighbors and if possible, don't leave our campsite before they have had their cup of coffee in the morning.
Need to rethink 4, 5, 6 above based upon whether you have the Thomas TA4101 system or not.
HTH, Neal
Title: Re: Airing tires from onboard hose.
Post by: ltg on March 15, 2018, 10:52:04 am
Very few Forum Members have a coach newer than the 2006 model years. But, sometimes after 2006, Foretravel removed the Wilkerson Filtration system from the 12 volt aux air compressor. A few years ago I spoke to Foretravel about this. It was confirmed that the Wilkerson Filtration system was removed and said that Foretravel had decided that it was not necessary on the 12 volt air compressor system. They further stated that it would be ok to remove it from my 2005 model. I decided to leave the system in place. I used the 12 volt aux compressor quite often to air up my tanks before I started the main engine to leave a campground.
Title: Re: Airing tires from onboard hose.
Post by: jcus on March 15, 2018, 01:15:08 pm
Very few Forum Members have a coach newer than the 2006 model years. But, sometimes after 2006, Foretravel removed the Wilkerson Filtration system from the 12 volt aux air compressor. A few years ago I spoke to Foretravel about this. It was confirmed that the Wilkerson Filtration system was removed and said that Foretravel had decided that it was not necessary on the 12 volt air compressor system. They further stated that it would be ok to remove it from my 2005 model. I decided to leave the system in place. I used the 12 volt aux compressor quite often to air up my tanks before I started the main engine to leave a campground.
Larry, I also use the dash switch to allow the aux compressor to fill my tanks before I start my main engine. The Wilkerson system has a water separator and a desiccant filter to remove any water that gets by the seperator. As long as you change out the desiccant when necessary, I see no problem with this.
Title: Re: Airing tires from onboard hose.
Post by: bbeane on March 15, 2018, 01:58:38 pm
My 1999 has all 6 wheels aluminum. Much adoo about airing up tires.
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 15, 2018, 02:05:22 pm
My 97 320 has six alloys.
I vaguely remember something from long ago about reactions between steel and aluminum and a copper colored spacer between them? Maybe the dura bright later wheels do not need it?
Title: Re: Airing tires from onboard hose.
Post by: John and Stacey on March 15, 2018, 02:17:13 pm
Mine also has aluminum inner wheels. John
Title: Re: Airing tires from onboard hose.
Post by: Chuck & Jeannie on March 15, 2018, 02:19:32 pm
I have six from the factory. This thread will be hijacked long before it is beaten to death!
I got 6 from the corner store...
Title: Re: Airing tires from onboard hose.
Post by: Caflashbob on March 15, 2018, 10:20:38 pm
Dissimilar metals can cause corrosion without protection
Title: Re: Airing tires from onboard hose.
Post by: Mike J on April 10, 2018, 01:49:15 pm
Been awhile getting back to the forum. To identify our aux air compressor required finding someone able to wriggle into the basement alongside the wheelchair lift. Very little space available.
Update on aux air compressor in our 02 U270. Neal Pillsbury correctly named our aux air system. From his earlier post:
" In model year 2002, FT started using the Thomas TA4101 12Vdc, 1/3 HP, 100 psig (max.), auxiliary air compressor. I believe that is what you should find in your coach. The reason they did this was due to the need for a higher duty rating and a more robust compressor when slides were added to the coaches."
Pictures attached. Yes we have the Thomas 4101. (even though we do not have any slides) The desiccant container is visible as are two water traps. Neal, is this the Wilkerson filtration system you mentioned?
Newbie question: Are there separate desiccants/filtration systems for the engine air compressor and the aux Thomas compressor?
Is the Thomas a good unit? Is it strong enough to air the suspension to travel mode without damaging itself, overheating etc. (I suspect the answer is no. Isn't the aux unit only designed for maintaining level and slide operation...True/False?) I might consider running it more often if there were no issues using the aux compressor to achieve travel mode and airing tires. It would be nice to avoid running the Cummins and disturbing our park neighbors. Could make our departure from campsites a bit quieter without any extra diesel exhaust as well.
Title: Re: Airing tires from onboard hose.
Post by: jcus on April 10, 2018, 01:59:37 pm
Jim, Interesting suggestion. Not sure about our available space. Will have to check out the dimensional specs.
Are you using this as a total replacement for the FT OEM aux compressor equipment?
My OEM Thomas is still there and working. This system is separate and plumbed to wet tank, but has a crossover with a valve to my slide/hwh leveling line incase the Thomas goes out. You probably could use it as a replacement, footprint is smaller than the Thomas.
Title: Re: Airing tires from onboard hose.
Post by: Keith and Joyce on April 10, 2018, 02:46:18 pm
Amazon link to the compressor Jim recommended:
Amazon.com: Viair 45040 450C Air Compressor Kit: Automotive (https://www.amazon.com/Viair-45040-450C-Air-Compressor/dp/B000FQ78VI)
Keith
Title: Re: Airing tires from onboard hose.
Post by: Mike Leary (RIP) on April 10, 2018, 02:49:17 pm
Been awhile getting back to the forum. To identify our aux air compressor required finding someone able to wriggle into the basement alongside the wheelchair lift. Very little space available.
Update on aux air compressor in our 02 U270. Neal Pillsbury correctly named our aux air system. From his earlier post:
" In model year 2002, FT started using the Thomas TA4101 12Vdc, 1/3 HP, 100 psig (max.), auxiliary air compressor. I believe that is what you should find in your coach. The reason they did this was due to the need for a higher duty rating and a more robust compressor when slides were added to the coaches."
Pictures attached. Yes we have the Thomas 4101. (even though we do not have any slides) The desiccant container is visible as are two water traps. Neal, is this the Wilkerson filtration system you mentioned?
Newbie question: Are there separate desiccants/filtration systems for the engine air compressor and the aux Thomas compressor?
Is the Thomas a good unit? Is it strong enough to air the suspension to travel mode without damaging itself, overheating etc. (I suspect the answer is no. Isn't the aux unit only designed for maintaining level and slide operation...True/False?) I might consider running it more often if there were no issues using the aux compressor to achieve travel mode and airing tires. It would be nice to avoid running the Cummins and disturbing our park neighbors. Could make our departure from campsites a bit quieter without any extra diesel exhaust as well.
A. "Newbie question: Are there separate desiccants/filtration systems for the engine air compressor and the aux Thomas compressor?"
Yes: They are distinct, separate systems. The main (engine) air/braking system Haldex (Midland Grau) desiccant and coalescing filter tower is mounted on the engine frame. The auxiliary Thomas compressor Wilkerson filtration and desiccant bowls are mounted at the aux. compressor.
B. The desiccant container is visible as are two water traps. "Neal, is this the Wilkerson filtration system you mentioned?"
Yes: Your pictures show the Wilkerson System drying components; (2 dry bowls and the desiccant bowl) that are used to strip moisture from the Thomas TA4101 auxiliary air compressor exhaust stream. While some readers may not understand or condone going to the extra effort of avoiding moisture in their air systems/tires, my experience in power plants has shown me the folly of not attending to that detail. In an air system, one either attends to moisture-free air up front or one has to pay the price, in much more costly terms, down the road.
The nuisance of the Foretravel/Thomas TA4101 compressor/Wilkerson drying components auxiliary air system design is that the drying components are sized for and the design assumes a reasonably tight air system. The operation of the relief valve and automatic blowdown solenoid also often fail and thus detract from system reliability. The desiccant, while easy to change if the desiccant bowl is easily accessible, is expensive (but there are several threads on how to minimize that factor — Desiccant option for the HWH system (http://www.foreforums.com/index.php?topic=12784.0) . So, with a minimally sized design, if you don't correct your air leaks, you soon exhaust exhaust the desiccant and the rest of the air system components start to suffer.
C. "Is the Thomas a good unit? Is it strong enough to air the suspension to travel mode without damaging itself, overheating etc."
Absolutely yes: The 12 Vdc Thomas (and not mentioned in this thread before, Gast) brand units are industrial/commercial application standards for medium duty air systems. They are rugged, durable, high (%) duty cycle, reliable standards. They use high quality cast iron frames with excellent heat transfer and their designs employ long life components that are rated to last 6,000 hours before minor rebuild and 12,000 hours before major overhaul. In a coach air system (that is kept reasonably tight and leak free), that is more than (2), 30 year coach lifetimes with a 2 minute auxiliary tank (replenishment) pump up once per day and a 15 minute pump up (of all coach air systems), EVERY day, before getting underway. Minor and major rebuild kits are expensive, but they reflect the component quality level and are readily available.
Prevost conversions, that have much higher needs than FT's because of their pocket doors, gen sets on air suspensions, air flush toilets, higher pressure air bags, etc., use Thomas and Gast compressors. When they need more volume, they step up to 2 cylinder Thomas and Gast compressors first and then to 115/240 VAC compressors next.
There are other light to low/medium duty options, like the VIAIR units. But what isn't being said about the VIAIR's is that they are primarily focused on marketing/cosmetics whereas Thomas' (and Gast's) are focused on robust longevity and durability.
The VAIR units are widely used in applications where mobility is of primary importance such as in off-roading tire re-inflations (slow, but a decent, mobile backup to the premium Power Tank (CO2) choice), where peak ceiling pressures are compatible with non adjustable hysteresis characteristics, or in hardwired applications where appearance is of paramount concern and longevity is of secondary importance such as in air horn add-ons, show cars with trick pneumatic suspensions and where the air compressors themselves are an intentional part of the visual "candy", etc. The Thomas and Gast compressors are decidedly "Plain-Jane, Industrial" by comparison.
There are plenty of reasons for any of the options. Just make sure that you stay focused on DRY, CLEAN AIR. Speed of air-up, ceiling pressure, hysteresis (difference between compressor set and reset pressures), looks, and durability choices abound, but unfiltered, wet air should never be one of the choices.
HTH, Neal
Title: Re: Airing tires from onboard hose.
Post by: jcus on April 10, 2018, 09:56:35 pm
A. "Newbie question: Are there separate desiccants/filtration systems for the engine air compressor and the aux Thomas compressor?"
Yes: They are distinct, separate systems. The main (engine) air/braking system Haldex (Midland Grau) desiccant and coalescing filter tower is mounted on the engine frame. The auxiliary Thomas compressor Wilkerson filtration and desiccant bowls are mounted at the aux. compressor.
B. The desiccant container is visible as are two water traps. "Neal, is this the Wilkerson filtration system you mentioned?"
Yes: Your pictures show the Wilkerson System drying components; (2 dry bowls and the desiccant bowl) that are used to strip moisture from the Thomas TA4101 auxiliary air compressor exhaust stream. While some readers may not understand or condone going to the extra effort of avoiding moisture in their air systems/tires, my experience in power plants has shown me the folly of not attending to that detail. In an air system, one either attends to moisture-free air up front or one has to pay the price, in much more costly terms, down the road.
The nuisance of the Foretravel/Thomas TA4101 compressor/Wilkerson drying components auxiliary air system design is that the drying components are sized for and the design assumes a reasonably tight air system. The operation of the relief valve and automatic blowdown solenoid also often fail and thus detract from system reliability. The desiccant, while easy to change if the desiccant bowl is easily accessible, is expensive (but there are several threads on how to minimize that factor — Desiccant option for the HWH system (http://www.foreforums.com/index.php?topic=12784.0) . So, with a minimally sized design, if you don't correct your air leaks, you soon exhaust exhaust the desiccant and the rest of the air system components start to suffer.
C. "Is the Thomas a good unit? Is it strong enough to air the suspension to travel mode without damaging itself, overheating etc."
Absolutely yes: The 12 Vdc Thomas (and not mentioned in this thread before, Gast) brand units are industrial/commercial application standards for medium duty air systems. They are rugged, durable, high (%) duty cycle, reliable standards. They use high quality cast iron frames with excellent heat transfer and their designs employ long life components that are rated to last 6,000 hours before minor rebuild and 12,000 hours before major overhaul. In a coach air system (that is kept reasonably tight and leak free), that is more than (2), 30 year coach lifetimes with a 2 minute auxiliary tank (replenishment) pump up once per day and a 15 minute pump up (of all coach air systems), EVERY day, before getting underway. Minor and major rebuild kits are expensive, but they reflect the component quality level and are readily available.
Prevost conversions, that have much higher needs than FT's because of their pocket doors, gen sets on air suspensions, air flush toilets, higher pressure air bags, etc., use Thomas and Gast compressors. When they need more volume, they step up to 2 cylinder Thomas and Gast compressors first and then to 115/240 VAC compressors next.
There are other light to low/medium duty options, like the VIAIR units. But what isn't being said about the VIAIR's is that they are primarily focused on marketing/cosmetics whereas Thomas' (and Gast's) are focused on robust longevity and durability.
The VAIR units are widely used in applications where mobility is of primary importance such as in off-roading tire re-inflations (slow, but a decent, mobile backup to the premium Power Tank (CO2) choice), where peak ceiling pressures are compatible with non adjustable hysteresis characteristics, or in hardwired applications where appearance is of paramount concern and longevity is of secondary importance such as in air horn add-ons, show cars with trick pneumatic suspensions and where the air compressors themselves are an intentional part of the visual "candy", etc. The Thomas and Gast compressors are decidedly "Plain-Jane, Industrial" by comparison.
There are plenty of reasons for any of the options. Just make sure that you stay focused on DRY, CLEAN AIR. Speed of air-up, ceiling pressure, hysteresis (difference between compressor set and reset pressures), looks, and durability choices abound, but unfiltered, wet air should never be one of the choices.
HTH, Neal
http://beamalarm.com/Documents/thomas_ta-4101_dc_specifications.html Neal, think this is the problem with the Thomas for airing up the tires, unless your tires require less than 100 psi. For the rare times I need to inflate my tires to 115 psi, I do not think the "low/medium duty" Viair is going to be a deal breaker for me. It is rated for continuous duty. From a search of the forum, it appears the Thomas, even if rated for 6000 or 12000 hours, is not overly reliable, as there are many threads on this and other forums about their replacement.
Title: Re: Airing tires from onboard hose.
Post by: rbark on April 10, 2018, 10:16:32 pm
It also looks like Mike J needs to change his disaccant on that 12V system
Title: Re: Airing tires from onboard hose.
Post by: Neal Pillsbury on April 10, 2018, 11:24:12 pm
Thomas TA-4101 DC Specifications (http://beamalarm.com/Documents/thomas_ta-4101_dc_specifications.html) Neal, think this is the problem with the Thomas for airing up the tires, unless your tires require less than 100 psi. For the rare times I need to inflate my tires to 115 psi, I do not think the "low/medium duty" Viair is going to be a deal breaker for me. It is rated for continuous duty. From a search of the forum, it appears the Thomas, even if rated for 6000 or 12000 hours, is not overly reliable, as there are many threads on this and other forums about their replacement.
Jim C,
Not a problem. As I said, to each his own.
I use a (CO2) Power Tank because I can top off all eight coach tires plus four trailer tires in less than 15 minutes, on a bad day.
Out of curiosity, I have used a close friend's VIAIR. Then, for quite some time, I imagined that I couldn't achieve my required front axle target of 115 psig — on just one tire — in over 15 minutes of trying. Then the audible cues finally dawned on me and I subsequently proved that if I was starting at greater than 110 psig in the tire, I first had to connect the VIAIR to the tire, then I had to momentarily let the "sensed pressure" (teed valving arrangement) in the tire down below 108 psig (in order to achieve VIAIR compressor reset) and then the VIAIR would pump the tire up to 115 psig in about 8 minutes (as I recall). Of course a reservoir tank would alleviate this but then the whole tank would need to be cycled below 108 psig occasionally in order to get the VIAIR to "kick-In".
At any rate, if I didn't have the Power Tank, for some reason, I would still use the Thomas to bring the needed tires up to 100 psig. Then I'd use the coach service air system to top off, because that would be much faster.
I don't agree that the Thomas and Gast compressors are unreliable. Every failure that I've personally seen or read about (if there were sufficient details) was also accompanied by air system abuses (uncorrected, long term air leaks and continuous or near continuous aux. air compressor running without corrective actions being taken.
The Thomas and Gast compressors are continuous-run-rated at 100 psig @72 degrees F, just like the VIAIR. But, to my knowledge the Thomas cannot be adjusted to greater than 100 psig. The duty cycle of the VIAIR's, at least the ones I've seen and used, drop off as one goes higher than 100 psig and one needs to manually interpret and compensate for that. Even the industrial grade 150 psig VIAIR's have a 33% duty cycle at higher pressures (run for ten minutes, then shut off and let cool down for 20 minutes). VIAIR Internal, self thermal protection cuts in if one exceeds the internal, unadjustable VIAIR limits.
Not a problem, DWMYH, Neal
Title: Re: Airing tires from onboard hose.
Post by: jcus on April 10, 2018, 11:42:41 pm
Read the specs. 450C Compressor | VIAIR Corporation (http://www.viaircorp.com/c-models/450c-compressor) Had an bad protection valve on my coach and would leak down to 0 psi in 24 hours. Have used the 450c to bring it back up to 115 psi many times, not quickly, took maybe 15 minutes, but did it every time. Maybe you are looking at a different compressor, but the 450c is rated at 100% duty cycle, when it craps out, like my Thomas did on a previous coach, I will certainly post it. By the way, not positive, but think Newell changed from Thomas/Gast compressors to Jun-Air some time ago. I am an old guy, but if new technology comes along, I am willing to try it out, and if it's better, use it.
Title: Re: Airing tires from onboard hose.
Post by: John44 on April 11, 2018, 10:25:05 am
Anyone ever check out the "California air tools" compressors,they are 110 volt.
Reply to post 18,Roger if you are using air from the engine air compressor you should not have to use any filter or seperator,if you actually catch oil or water you have a problem,if using it with outside air then that's another story.
Title: Re: Airing tires from onboard hose.
Post by: Chuck & Jeannie on April 11, 2018, 10:39:48 am
Anyone ever check out the "California air tools" compressors,they are 110 volt.
I did - not a happy experience. See Reply #20 in thread kinked below:
110V Aux Air Compressor Install (http://www.foreforums.com/index.php?topic=31836.0)
Title: Re: Airing tires from onboard hose.
Post by: Roger & Susan in Home2 on April 11, 2018, 10:40:46 am
John, I use the oil/water separator with my onboard 200 psi 120v DeWalt compressor when adding air to tires or the leveling system. Pretty handy for bike tires and anything else that needs air too.
110V Aux Air Compressor Install (http://www.foreforums.com/index.php?topic=31836.msg285975#msg285975)