I'm sure I've said this way too many times already, but always check your tire air pressure with a "real" pressure gauge before you start driving each morning. Don't depend on a dashboard tire pressure monitor. Visually inspect your tires as you check the air pressure. The past couple of times I've checked my tires before starting the engine I've found one of my inner duals low on air pressure. Yesterday I found it completely flat. The alarming thing is that the outer dual looks normal even when the inner dual is completely flat. Apparently my coach is nowhere near its maximum load for the tires I have. I looked at both outer duals, one with the inner dual completely flat and the other with the inner dual at normal pressure and I honestly couldn't see any difference. I called for tire service and the tire dude found nothing wrong with the tire. The braided hose from the valve stem of the inner dual was leaking so he removed them from both inner duals and installed caps that I can check the pressure and add air through. I need to get a straight air chuck and pressure gauge instead of the angled chuck and gauge. He told me the braided hoses almost always leak and the caps he installed almost never leak. I wish I could remember what he called the caps. Maybe another reader can fill in that bit of information for me? A while ago someone on this forum told a story about blowing an inner dual, replacing it, then blowing the other inner dual shortly thereafter, then buying a whole new set of tires because he thought his tires were to blame. If that coach had braided lines on the inner duals they could have caused that exact scenario. The inner dual on the other side of my coach had a tiny leak that I never could find and I suspect it was also the braided hose. My very strong suggestion is that you get rid of the hoses on your inner duals and use one of those caps you can check and add air through with a straight chuck and gauge... and always check your tires with a "real" pressure gauge before you start up in the morning... Sure hope this saves the day for someone reading this. It saved at least one of my tires for sure.
I feel confident using my Pressure Pro TPMS system to check tire pressures without letting a little bit of air out each time.
Be sure to wipe the road grime off of the air through caps, I've had them leak as well. I just remove mine to check the air.
Say what you will about about easy ways to check tires.but buy a good tire.gauge and check them yourself. As everyone should know Heat and under inflation are tires worst enemy. Do.what you want there your tires. Just my thoughts.
I've worked at four national parks so far and they all have brand new trucks from GM, Ford, and Dodge with tire pressure monitors on every one of them. The tire pressure monitors never work on any manufacturer's truck. I took a Dodge to the dealer Monday and when I left their lot the tire pressure monitor malfunctioned immediately. I took a Chevrolet to the dealer last week and today I was told it's malfunctioning already. A year ago I was considering buying a tire pressure monitor so I asked on this forum if anyone ever had a coach tire saved by a pressure monitor but nobody responded. There are probably a hundred people on here with tire pressure monitors and I'm sure they'd say so if they'd had a save... I strongly suggest you never rely on safety devices as a substitute for human observation. A tire monitor is a very unreliable machine that isn't able to see problems with the tire, like a nail in the tread or a crack in the sidewall. It may tell you the tire just lost pressure, after it's too late, if it works at all. I've driven dozens of brand new trucks with factory installed pressure monitors that always malfunction. I kinda doubt the aftermarket tire pressure monitors are better than the factory installed ones, but whatever, I warned you and that's all I can do.
As a mental exercise here, I don't understand how underinflation could cause inner duals to blow. If you think about it the underinflated tire will be pressing less against the road and will carry far less of the weight.
My theory (and it really is just a crazy theory with no evidence whatsoever) is that inner duals always ride 10-15 degrees hotter than the outer tires and thus they always ride with slightly higher pressure than the outside. Also looking at the way the asphalt roads wear, I think the inner duals always shoulder the majority of the weight on a well worn road.
Under inflation cause Heat, Heat causes the tire to break down..over time the tire will fail if you Go to any tire manufacturer and asked them about heat and under inflation and see what they say.
I have read; that a difference of 10 pounds of air between duals will render the lower inflated tire flat, the consequences of driving on a flat tire will materialize. Tom
Having had three front tire blowouts in my lifetime I do not wish for any more. The front tire on my crane had been serviced at a Michelin approved service center the morning of my second blowout. I have checked my own pressure ever since.
When we bought our coach it came equipped with 3" extensions on the inside dual valve stems, probably so the PO could check air pressure easier. Both main valve stems cracked at the base of the threaded portion where the extensions screwed on. Apparently "all that weight" constantly flexing the threads caused the stem metal to fatigue at the thread base and then crack and then leak air, and then new tires (at $500 a pop).
No valve extensions for me!! Just have long main stems put on and get a straight line air chuck and air gage. Lots cheaper!!
Yikes! Glad you weren't hurt.
I check my tires manually. My TPM is just another layer of protection.
Check the fronts, and use these on the rear. Crossfire - Dual Dynamics (http://dualdynamics.com/products/cross-fire/)
Ditto Jeff's comment. But I would add, our TPMS (Truck Systems Technologies) reports not only the tires' pressures, but also running temperatures. Perhaps other systems do, too, but for us that's the key. Another Forum member recommended TST to us, based on having had a blowout that would have been caught in advance *IF* the rising temperatures were being monitored and an audible alert had sounded. If a random nail or cause of puncture is picked-up along the route, the rising temperature resulting from under inflation will trigger an alert.
The TST system has such an alert. It is based on user defined ranges for pressure, relative to coach/axle weight, but ALSO for temperature.
We know not to put too much reliance on ANY single digital or mechanical system. "Belt and suspenders," right? But we've been very happy about what we have learned about tire performance, by carefully checking all pressures with a good gauge before departure, but also watching the tire pressures and temps on a real-time basis as we drive.
I have had an RV of one sort or another for more than 40 years and just got into the habit and stuck with it of doing a tire pressure, oil level and coolant level check every time while making preparations for getting underway with the coach. It only takes a few minutes. It has the advantage of looking at the tires, looking at the engine belts, fuel filter and the engine, noticing any leaks or anything that doesn't look normal. I like the TPMS for real time alerts but the tire pressure is what I read on the gauge.
A few minutes before departure to just do some basic checks can save a you from a major problem, time and money down the road. And taking a few minutes to do something routine slows you down a bit and gets you ready to hit the road in a better frame of mind.
I have a Crossfire system on the rear duals which alerts me if one of them is low. Essentially, the Crossfire system interconnects both tires of a pair and keeps them equal (and allows me to air up both at the same time). I double check air pressure manually on all tires.
I have TPMS sensors on to alert me of an issue while we're in motion; especially an issue with the toad.
We check the TPMS readout every 15 minutes while traveling. It's the co-pilot's responsibility.
Craig
I had the extensions leak and got rid of them. It's a little bit harder too check my pressure but worth the piece of mind. I also check
my tires for heat with my hand.
While monitoring both PSI and temperature can be "interesting", is is clearly redundant.
The Ideal Gas Law (PV=nRT) explains (yes a LONG time ago), that PSI WILL (not might) increase a given amount with a given increase in temperature.
Said another way, monitoring PSI will tell you "all you need to know". Unexpected decline or rise in PSI demands immediate attention.
Note, attention can mean nothing more than confirming that the tire with high PSI is in the sun! But, a sudden unexplained change calls for further investigation.
My Goodyear dealer, who shod all my trucks and two coaches, told me they were, "an expensive accident waiting to happen".
A supported extension with a rubber piece in the outer rear wheel with the fill through cap is what my cummins and high volume FMCA tire dealer both recommended and installed.
Had rear inner dual leaks without the support on the inner dual extension so I understand the concerns
Unless it was a fail proof support--notice I did not say foolproof--for the extensions I would be apprehensive of installing them. If they came out of the hole in the outer dual they would just add additional weight/centrifugal force exerted on the valve stem and subsequent possible early failure.
More often than not, I bounce my hammer off each tire before getting under way. The old hammer bounce trick can really give you what you need to know and you get used to what the bounce feels like for a normal tire. If suspect, drag out the tire gauge and check it out. Yes, I even bounce the front tires just to keep up to speed on the proper bounce. Just an "old man's" way of doing business. Have a great day ---- Fritz
A TPMS system will work or it will not. Nothing to do with Ford or Dodge, VW, Mercedes, or anyone else. It will not give false readings only good, or none at all. We have had both the portable version and now the Silverleaf system on both a GV and the 320 and they either work well, or not. Usually a bad battery, and new ones needed every year or so. Planned maintenance and change them all once one goes bad is the answer. On our VW Touareg the sensors inside the wheel can be a problem, but the screw on caps on the coach work fine, and on the Toad..
The metal extensions have been gone over before. They will fail and take the standard extension with them just a matter of time. A good support will help, such as the rubber discs that fit into the holes of the outer wheel. Flex hoses need support as well but have their own problems with leaking.
The dual systems seem to work OK as many trucks have them and that combined with a good TPMS is the easy way of keeping track of the pressures.
The hammer/tire iron is good way once you get the tone correct.
On larger airplanes if one tire bursts then the other one on the same axle has to be changed as well due to the extra load and heat that it took when the other one failed.
Stay safe out there.
Speedbird 1.
I guess none of us know how to read a pressure gauge properly, including the dealer, because all of our tire pressure gauges show the correct pressure on the tires even though the tire pressure monitors on all these new trucks say the tire pressure is wrong. All these brand new trucks are still under warranty and have been back to the dealer multiple times. This was true at all four national parks I've worked at so far... I hope the main point of my post wasn't missed. I wanted to warn everyone about the braided extension hoses. If anyone reading this missed that please go back to the top and read my initial post because this is a dangerous situation... Please start a separate discussion about these tire pressure monitors. I will not be participating in that discussion. I now have a lot of experience with them... unfortunately.
Pressure Pro TPMS saved our behinds once for sure. Our lives ride on tires. Best insurance ever.
Our coach came with a Crossfire on the rear tires. I really like it. Easy to visually confirm pressure with my "nearly every stop" walk around.
I see the benefits and drawbacks of TPMS.
I also have a no contact thermometer for periodic checks of tires, brakes, and dog rib cages.
Where are our flat-proof non- pneumatic coach tires?
Cross fire and gauge