[Dave]

Jerry,

Just to help isolate the problem try this. Put your coach in the driving or ride position. Make sure the HWH is disabled. Shoot it if you have to because it might be the problem. This test is invalid if the HWH is trying to keep the coach level so it has to be turned off.

Once the coach is level raise the tag axle. That will result in a drop at the rear, but keep the bus running until it has returned to the driving height. Measure the heights side to side and front to rear so you have a way to quantify if it does settle or lean.

What you have done by doing the above is eliminated the tag axle air bags from the equation. Lets us know the result.

Did I mention the HWH has to be “off” for any of this to begin making sense?

[Greg]

OK, I’ll try that tonight Jon.

The HWH stays off when the green “Travel” light is on. That green light stays on all the time unless you are leveling.

I’m sure you mean find the breaker and kill all power to the HWH.

I’ll let you know.

[Jerry]

The green light stays on anytime the HWH is off, which is “travel” mode. If I turn any other button on, then the green light goes out, and the Level Low light on dash comes on. I cannot turn the breaker off, it is a push button breaker, but I cannot trip it. It will not pull out like an airplane. So as the picture shows, it is off.

Jon, I cranked the bus, put it on high idle, let the air build up and measured the height from ground to the bottom rail of bay in front of drive axle. It was 12″. I then flipped the lever on the tag axle dump, and the tag dumped pressure, the bus lowered in the rear, and the measurement went down to 10″. I let the bus run for a while, and it did not raise up any, just stayed there. I went back and flipped the lever back, and the tag restored air, and the bus raised back up to the 12″ i had earlier. Should it have raised back up?

The one thing that I noticed different tonight was, during the last week that I have been working on this, I have aired the bus up each time with shop air, all the way to 125lbs. Every time I do that, I hear an air leak under the bus that sounds like it is coming from the area of the air dryer.

So tonight, I put a little shop air in to tighten the belts, disconnected shop air, and cranked the bus to do the above checks. What is different now, when I shut the bus off, I hear NO air leaking under the bus like I have every time with using shop air.??

So is there some valve that may have been fooled, or open by the shop air, that closes with bus air? I don’t know, but guess I will find out in the morning if it’s still up.

I had even made an appointment for Monday with a local truck shop to use their pit to find the leak I have been hearing. My wife has heard it each time, and now she doesn’t hear it either (figured I needed a witness).

So, guess I’ll wait another day to see what it does overnight.

[jack]

If you use shop air, and go past where the trip point of the air dryer is, it will dump air until you disconnect the shop air source. Mine does the same thing…my compressor (shop air) is set higher than the engine air compressor, and it cycles the air dryer and then leaks out until I shut off or disconnect the shop air.

That may be what you are hearing…..

[Archived]

Mark, yea, it does that, but even after I disconnect shop air, it continues to leak until it’s all gone. Aux air that is.

[Archived]

Hang
in there Jerry, you’ll get it narrowed down..

If
your hearing air under the bus, you need to determine where it’s
coming from. Mine will leak air like Mark said while on shop air
until I unhook the shop air and then sometimes continues to leak. Has no effect on the suspension.

I
know this is driving you crazy, but are you absolutely certain there
are no leaks on each side in the rear? Did you isolate each bag as I
suggested before with shop air unhooking each line and pressurizing
the bag, lines and ping tank? If you didn’t do this, I’ll bet money
you have a leak on each side.

You
have to unhook the line from the 5 port to the front bag, line and
ping tank and pressurize.

Then
go to the second bag and do the same thing, line, bag and ping.

Then
go to the tag bag that also has the 3 port attached and do the same
thing, bag and ping.

Leave
each test pressurized for an hour or so and if your losing any amount
of air, you just isolated the problem.

If
all of that is good, you have to go up front.

[Archived]

I am Tom, but just seems to odd for both sides to leak down since they are not supposed to be connected.

I have not checked pressure individually. Just got through with replacing Norgrens last night. So I will do that next.

Bet I’ve sprayed 10 gallons of soapy water! LOL

[Archived]

When airing up to ride height and one side in the front is higher than the other what is causing this? There is only one ride height valve in the front. In the center just behind the front axle. The height will equal out if I drive down the rode. Rick

[Archived]

Jerry,

Your question about leaking air has been answered. I doubt if that has any impact on the suspension. If you want to verify what is happening just check the pressure at the schrader valve at the rear when you hear the air leak and I suspect you will watch that drop down to the 120-125 psi set point, and possibly down to zero, but your dash gauges should still show max pressures, including the aux system.

By lifting the tag, and getting the bus rear end up as high as it will go with the tag lifted it isolates the tag axle air bags and narrows the area you have to check for the problem you are having. My concern with the HWH is to insure that it is not working behind the scenes trying to level the coach with the key off which could cause a fairly rapid loss of aux air, but also could impact whether the coach sags or leans due to lack of sufficient air pressure.

An unknown to me is relating to the HWH and someone with experience has to jump in and verify it ceases to function with the key off. My first coach with the three position switch “drive, manual, and automatic” would keep the coach level as long as there was aux pressure even with the key off if it was in the “automatic” position.

[Corey]

Jerry buy some stuff called leak check its used to check gas lines air conditioning lines, soap and water does not hang around long enough to find small leaks , that’s what I use ….. Maybe that will help you too !!!!!

[Archived]

You can disable the HWH auto leveling by pulling a certain fuse in the brain box. Back in my CC days, everyone new that fuze location in case you had trouble on the road, you could then manually level to road height to get going. HWH wouldn’t give out the info, but it was common knowledge. If you have the HWH paperwork, you can probably locate that fuze location. I also thought you could turn off the auto level by pushing a button on the panel, greeen light would go out.

[Archived]

The only time the Green light will go out is when the key is off. The only time it is activated (supposedly) is when you press the air button. The green light goes out when you press the air button which starts the auto level if you press it twice. If you press it once, then you can manual level. The green light is always on when traveling, signifying “travel mode”.

I will try to find the fuse you are talking about.

[Archived]

Took the supply line loose from the 5 way for the starboard side air bags on rear, pumped it up to 90 lbs. In 1 hour, it lost 3 lbs. Did the same thing for the port side, it lost 10 lbs. per hour.

Front doesn’t sag or leak any.

I’ll continue my search for more leaks.

I did tighten the fitting on my guage where you see the bubbles. All new valves, no leaks on any of them.

Made the tester out of a 2″ air guage, brass tee, schrader valve, and 3/8 hose compression fitting.

[Chas]

Here is something to consider………..

When the coach is leveled using the automatic feature or ride height valves the air bags get only enough pressure to put the coach in the level or driving position. The automatic nature of how the systems function limits the pressure to “just enough”. In fact the only time the air bags have an excess of pressure in them is when you try to raise the coach to its maximum height.

So regardless of whether the leak is 10 PSI per hour or 1 PSI per hour once the key is off the coach begins to lean or settle. Depending on the size of the leak it might be quickly noticed, or it might take longer, but as long as there is any loss of pressure in the air bags the certainty is the coach is going down.

But for discussion purposes imagine your coach has been leaning left. That suggests strongly that you have a leak in one or more of the three air bags in the left rear, or any of the valves or fittings in the left rear. It doesn’t matter where, it just matters that the coach is going to lean.

So when you sit on a level site your air bags are going to leak down at some rate and the leans will be noticed. But pretend you are on an unlevel site. And that site slopes so the only way to level the coach is to fully raise the left rear. Imagine that you choose to do that manually and that you don’t stop adding air until the air bags on that side have all the air pressure you can apply. Lets say 80 PSI raises the rear to its maximum, but you manually increase the pressure to 120 PSI. Now the coach may sit level for days before the leans show up, because the leak rate is 1/2 PSI per hour or 12 PSI per day which will take about 3 1/3 days before the air bag pressure on the LH side reaches the point at which the coach begins to lean.

The point being unless you chase leaks and know the rate of leakage as Jerry is doing you can get confused thinking a leak is intermittent or steady depending on how the coach is leveled, when in fact the leak rate never changes, but conditions do change.

[Dean]

Slowly making progress, found a leaking fitting on LR tag axle “football size tank”. And the 1/4 ” fill line going into the dryer, was leaking bad at the push lock fitting.

I’ve been airing up the bus so much with shop air, so I installed a regulator, filter and air chuck fitting .