I am still discovering and learning things about Ducky. I started looking around for the air hose connection and could not find one. The gas tank/LP bay has a quick connect fitting next to the LP tank. I am hoping this is the air hose connection, especially with the air hose coiled up on the shelf above the tank. Just wanted to make sure I was not trying to plug into an LP outlet.
(Guess you can tell from the question, that I have not had any experience with LP in my first 70 years.)
Would SKS please confirm that this is where to plug in the air hose?
Thanks,
Trent
Yea, that's where it was on our 320. Looks like an identical setup.
jor
Hi Trent,
That is the air line connection. It will give you air pressure to the limit of your engines air compressor.
Raymond
...which is usually just short of the pressure you want for your front tires.
Trent you probably have figured this out already but this is what I encounter. The air compressor with your engine may not be a good match to what you need if you need more than 95 or so psi.
Example. I need 110 psi. The max I can get out of the on engine compressor is 120, but as soon as I pull the tanks down just a little, I quickly have no reserve in the tank at that psi so the tire has more psi than the air tank and I cannot air it up. So I have to bleed off air to about 90 psi at which point the governor kicks the compressor back on, and when it is pressuring up in the 110 - 120 psi range I can again put air into the tire, for a moment.
If you want help on how to improve that scenario, send me a pm and we can talk about a gadget that will help. Or you can search and find where many of us have discussed this on the forum.
Mike
It is an issue to air up the fronts but the old wrangler was easy when we went to the beach.
I've been using the on-board air for my tires. Since the air pressure is 120psi only when the air pump stops and then drops with use to 90psi, I let air out to recycle the pump when trying to get the most air into my front tires. I can go as high as 115psi this way, which is all they need.
Where and with what are you guys measuring the pressure at the air hose connection? Is there a meter or gauge that displays that information? I did not see one near the air hose connection.
Thanks,
Trent
Initially, I just used the two gauges on the dash. Later on, I added a small gauge to the hose end, just before the quick disconnect fitting. The one I bought at Harbor Freight is part of small regulator assembly, but I just uses it for the gauge. It always reads exactly the same as the ones on the dash.
Although it tops out at 120psi, I have not been able to get more than 115psi into the tires this way. Which is fine.
Or build a gauge with a pressure release. I borrowed this useful idea:
Airing up the tires with coach air (http://www.foreforums.com/index.php?topic=17307.msg119157#msg119157)
I had our D2 replaced earlier this year and kept the old one. Just now I followed the links to the diagram of the "guts" of the D2. I decided to experiment with the old one. For those who haven't yet played with it, the cap unscrews. If it has been on there for some time you might have to help it a bit with a pliers. Then it is an easy matter to loosen the nut, turn the screw, tighten the nut and replace the cap. I say "easy matter" when the D2 is loose from the engine - it may not be so easy when you are standing on your head trying to see through the wrong part of the trifocals, but at least the theory is simple.
Replaced my D2 and high is 130 and low is 110.
MUCH BETTER BRAKES AT THE HIGHER PRESSURE
Bob, that sounds like a significant increase and may eliminate the difficulty some have reported about airing their tires sufficiently.
Now if you or SOKS will tell me what D2 is, I can improve my system too.
Thanks,
Trent
Bob, is it ok to use the other D2? Seems I recall admonition to not do that? If so, I do not recall why not?
Mike
Mike,
The very first service that I had done by Cummins in NH (in 1998), the service manager recommended that I change to the 110/130 D2. 16 years later, I've had zero problems and I've never seen a convincing reason to use the lower range D2.
FOR WHAT IT'S WORTH
Neal
Just like they say, to get the engine compressor to build more pressure, you have to remove air filler chuck and bleed off air tank to governor set point. But one quick way to bleed is to use an air filler with a trigger and an open chuck that continues to let air our when removed from tire valve. Most air chucks will close when removed from tire.
See http://www.bendixvrc.com/itemDisplay.asp?documentID=5644 (http://www.bendixvrc.com/itemDisplay.asp?documentID=5644)
here is a page from the Bendix Catalogue
We run 85-90 psi in tires and so have no problems. Nine years with this Foretravel and on the second set of tires. Lots easier that changing the D2. We don't carry that much stuff anymore.
I made up a tire inflator similar to Peter's: Airing up the tires with coach air (http://www.foreforums.com/index.php?topic=17307.msg114921#msg114921)
I bought all the components from the blue big box store. Attached a couple of pics.
Dave A
I used the 15 lb Power Tank for tire rescue while suffering from pressure pro design issues, today the air chuck in the RF compartment is to provide air to raise the coach with out starting the engine. I use shop compressor if wondering.
Elliott,
Thanks for the catalog page and the link.
Trent
Same as Dave, air in to raise the coach. I use an in-line air dryer.
I wish the aux air outlet was powered by the 12v compressor for filling bike tires and other stuff. After a several days, tank pressure is not enough. I suppose I could add a air connection into the 12v air plumbing.
I bought my tire inflater for about $12 at Amazon Clip on chuck, gauge shows supply pressure or tire pressure, has a deflater button. Accurate and easy.
On their own the llocal cummins dealer installed the 110-130 D2 as the 90-110 was sticking.
I did not know of the two different ratings till I read it here.
I had my coach weighed and calculated out the correct pressure on our 40' u320
Full fuel, water its 98/108.
Yours seems low? Steers better absolutely correct on tire pressure. Plus or minus 2 pounds are noticeable.
When I bought my spare D2 governors at Freightliner, the choice I was offered was between adjustable and fixed. I didn't know any better to ask about different ranges available. t am not sure why there would be a need for two "ranges", as the adjustable can be, well, adjusted... ::) The adjustment can raise or lower the 20 psi cut in/cut out range, so I wonder why there might be an advantage to getting one with a higher (or lower for that matter) preset range.
Don
Don,There are adjustable and non-adjustable governors available. NAPA, for instance, carries many:
New and remanufactured, Standard and Hi Temp, Hi, Lo psig, fixed and adjustable.
AS Examples:
TWD BEN800361 105-130 (New) $52.65
TWD BEN275200N 90-105 (New) $49.50
TWD BEN284358N 105-125 High Temperature (New) $56.25
TWD BENOR275491X 100-120 Standard Governor, (Remanufactured) Adjustable $19.35
As I understand it, the non-adjustable governors tend to be more stable and durable over the long term. The non-adjustable are OEM on the Peterbilts and Kenworths that I am familiar with.
Only the "cut-in" (or "cut-out"), depending upon how you prefer to think of it, set point is adjustable on an "adjustable governor", and then by only 5 to 10 psig ..................at least for reliability and repeatability over the long term. The non-adjustable governors have a fixed value internal spring that is then mechanically adjusted and factory locked at a specific cut-out value. "Hi" and "Lo" range D2's have different fixed value springs. The difference between "cut-in" and "cut out" is always non-adjustable on either fixed or adjustable Governors. What follows is from the Bendix parent document (Also previously provided by Elliott).
(Quote):"OPERATING TESTS""Start the vehicle engine and build up air pressure in the airbrake system and check the pressure registered by a dash or test gauge at the time the governor cuts-out, stopping the compression of air by the compressor. The cut-out pressure should be in accordance with the pressure setting of the piece number ( Governor) being used. (Common cut-out pressures are between 105-125 psi.) With the engine still running, make a series of brake applications to reduce the air pressure and observe at what pressure the governor cuts-in the compressor. As in the case of the cut-out pressure, the cut-in pressure should be in accordance with the pressure setting of the piece number (Governor) being used. (Common cut-in pressures are between 90-105 psi.) Never condemn or adjust the governor pressure settings unless they are checked with an accurate test gauge or a dash gauge that is registering accurately. If the pressure settings of the D-2 governor are inaccurate or it is necessary that they be changed, the adjustment procedure follows:
Note: If the governor cover is marked nonadjustable (and the adjusting stem has been sheared off), this is a non-serviceable governor and must be replaced with a new or re-manufactured unit.A. Remove the top cover from the governor.B. Loosen the adjusting screw lock-nut.C. To raise the pressure settings, turn the adjusting screw counter-clockwise. To lower the pressure settings, turn the adjusting screw clockwise. Note: Be careful not to over adjust. Each 1/4 turn of the adjusting screw raises or lowers the pressure setting approximately 4 psi.D. When proper adjustment is obtained, tighten the adjusting screw lock-nut and replace the cover.(Note: The pressure range between cut-in and cut-out is not adjustable.)"(End Quote)
Hope this answers your question,Neal
Knock on wood, no D2 problems here...yet. But WHEN they surface, where can I find the critter on my coach. Is it engine-mounted?
Brad, it's mounted on top of the air compressor. Looking at your eng from the back, it will be on the right hand side, just forward of the A/C pump.
Richard B
Thanks! Today's job is gonna be to replace the toilet seal...These jobs are so much easier to do while OFF the road. At 12 years (9 with me), and 78k miles, I'm thinking a little D2 insurance may be a good idea while off the road as well.
I have one as a spare for when I'll need it. Made sure it's the same PSI setting as the one in service. If it's good enough for the factory install, it's good enough for me :D
Richard B
Thanks Neal... I will dig out my new spare and see which it is. I suspect it is the 100-120 PSI rebuilt adjustable. I will turn up the one that is on there and see if will consistently cut out at 130 psi. Afraid I won't really be able to test the cut in until I work through the air dryer issue.
Don
All of this makes me glad I have a Hi-Volumn/Capacity 12V direct to battery connected compressor.. pc
I finally got a new one made by Max well and it is same as used by some of the tire shops in this area. $90. Nice easy to read.
JohnH
Learning is fun: Air GOVERNOR - YouTube (https://www.youtube.com/watch?v=9Vb32PL1PVU)
Yep, that's where it is on my coach, except to left of the LP tank.
Unfortunately any compressed air that does not go though the chassis air dryer rusts the steel cord belts inside your tires slowly but surely. Thin rubber over the cord plies allows water vapor through it.
Used to look at failed tires on coaches years ago. Rust inside them all.
Dry air only