Problem with Air System

[dale farley]

Let me say up front, that I don't think there is a button I can push or something that simple to solve this problem. I've noticed that several times when I park the coach and level it, the right side drops down after a short while. The air pressure stays about 110-120 on the dash gauges for a couple days before they drop significantly.

It was really cold for Florida last night; went down to freezing about 10 p.m. and got to about 18 by early morning. When I went to move the bus at 12:30 today, I started it and let it fast idle for about 10 minutes. The temperature at that time was about 36.

The "Low Level" light went off as it should, and the air gauges were normal. I started down the road and noticed the right side of the bus was not running level. Pulled into a parking lot, shut off the bus, started the bus again, put the air control to the "Drive" position and waited for it to stabilize. It never did. I manually lowered the left side of the bus and tried to raise the right side, but it moved only a fraction of an inch. The best I could get was the right side off the ground about 8" while the left side was 12.5-13". Unfortunately, I don't know of a good place locally to check this out for me.

Is there a switch or valve that may be causing this?

Is that a chance I can get to it to replace it?

Is it more likely that I have an air bag leaking? Would my dash gauges still be reading 110-120 after several hours if I had a bag that was leaking?

If I have a sticking valve, could the cold weather make it worse?

Can I get Jon to bring his pit to Florida to help me trouble shoot and repair this?

I wish there was something goofy I was doing that might compare to the heater problem I really didn't have. I have an idea that this problem may have been manifesting itself in other ways, because the people I bought the coach from told me that they always lowered the bags all the way every time they parked. Of course, when you do this, you don't notice that the right side looses air. But this is the first time it has failed to go to the "Drive" position while running.

[Jon Wehrenberg]

Dale, There is no silver bullet when it comes to the ride height and leveling system.

Your description of outside conditions had bells going off in my head and I am sure others will chime in on this. Cold temperatures make your problems with the leveling system show up. Eventually you have the problem under all temperature conditions, but when it is cold you see it first.

The lack of response when you put it in the "road" position suggests something you should check. Make sure your coach air system is not filled with water, or at least there is not water in any of the valves. Open a drain valve on each tank. You should see a little water in the tank ahead of the dryer, but virtually no water on any of the others. You may have had a leveling valve (one of the Norgrens) freeze due to trapped moisture or water.

Lacking the opportunity to check other stuff that is my first guess.

If this condition persists when temperatures are above freezing, it could still be moisture, and your valves could be filled with water.

But if that is not the case, and I hope it is not, listen for leaks. Air up the bus, and shut the coach down, leave the key on and push the buttons to manually raise the side that won't come up. Step outside and listen for leaks.

If it will not come up, but you cannot hear any leaks the number of different things it could be range from a bad ride height valve (located in front of the drive axle fender liner), to a bad solenoid valve that is not switching the Norgrens to the closed position so the ride height valve can function, to a bad Norgren valve.

Once the moisture problem or leaks are ruled out then it is a question of methodically trouble shooting the system, starting with the solenoid valve pack on the rear wall of the steering compartment to the ride height valve to the Norgrens.

I do not envy you. Can you get a fellow POG member to help you poke around with this?

[Joe Cannarozzi]

There are ride height valves in a compartment in the area in front of the drives. If you get on the ground and look up in front of the drives you can see it. It has an arm attatched to it and that arm is hooked to threaded rod that comes down and is attatched to a piece of 1inch angle iron comming from the frame. The 2 lock nuts that attatch the threaded rod at a hole drilled in that piece of angle iron you can loosen, this is your adjustment for the height of that corner. lenghten it the bus gets higher, shorten it itll go down.

Remove the "adjustment rod' completly from the bracket and manually test that valve by moving the arm all the way up. That should make the bus go up. There is a slight delay built in so give it a few seconds. If this does nothing check the line that is suppling air by loosening that fitting and listening to hear if air pressure is evident.

If no air evident going in thats the problem, If you do have air in, the valve is bad. If I were to guess I would think the ride height valve is bad, its a little less that 200bucks, and not too hard to repair.

When you shut the bus off there is a solonoid that seals or isolates the air bag from the rest of the bus. If a bag were possibly leaking slowly that is why the guages stay up and that corner goes down while parked, however, because of the fact that it wont come up while motoring tells me its not a leaking bag because a leak that large would be very easy to hear.

Mango might have this procedure on his blog.

[dale farley]

I was going to try to eliminate the water in the system, but so far, I have not found the tanks. My maintenance manual shows one "Accessory Air Tank" located at the front left corner of the coach, but this doesn't sound like what Jon was talking about. I tried to see under the bus but was afraid to get under there too far since it might come down on me. I did notice that as soon as I shut off the bus, the right rear bag started going down. Unfortunately, there is no other POG member in this area that I am aware of.

[dalej]

Dale, it sounds like your in some cold weather right now, so it won't do much good to check for water in the tanks untill all thaws. If temps get in the 40s you can check. If it got down in the 20s the lines will freeze if there was water sitting in the sagging part of the lines. You will know when it thaws, the bus will air up again.

There are two tanks above the drive axles and one above the steer axle. Again it won't help cause the frozen part will be a line, keeping air from passing.

[Joe Cannarozzi]

If its leaking down that fast you should be able to hear air escaping. That very well could also be an air bag or line to it if its going down that fast.

There are 2 more tanks at the drive axle on the frame rails. If you feal mechanicly inclined- raise the rear all the way up and block out the frame on both sides, prefferably a couple of 20Ton jacks or some OAK, crawl in there and drain. Jon has pics. up on the correct procedure and locations.


My Bus 057.jpg

My Bus 053.jpg

We replaced our drains with these enabling us to drain tanks easily and often.

We will also be going through the panhandle inbetween Christmas and New Year and Ide be more than happy to help you with whatever I can.

We usually fuel at the Flying-J, Midway, I think its exit 192, but we can also come down through Dolthon, Al. on 231 that puts us on I-10 at the 100mm or so.
Let us know we would love to meet you.

[Joe Cannarozzi]

Dale,
Did you ever happen to notice how often the air compressor starts and the air dryer "SNEEZES" while your driving?

Do the air pressure guages stay up while driving or are they constantly going up and down inbetween100 and 120?

[Jon Wehrenberg]

I think Roadrunner's problems are related to a leak. He and I passed a couple of emails and he mentioned he could see the right side going down, so from that it sounds like he can get it pumped up, but the leak is so bad it goes down right away.

As Joe says, he should hear that. Unless he has a safe way to raise it and block it up I am concerned about trying to get under it to get closer to the source.

Roger had a leak in one of his front air bags, but could not find it until he got under it and soaped it from the center of the bus between the wheels. But with Roadrunner's fast leak down, he is probably going to hear it, if not with his ears alone, but with a stethoscope aimed in the general area.

The problem is the leak can be a valve, and air bag, or less likely a fitting.

That does not suggest he does not check his system for water. On my 40 foot I had two tanks in the rear over the axles, one in the front over the axle, and one inside the steer compartment.

[MangoMike]

Whoa!

What happened to all the replies since Jon's this morning?

MM

[dalej]

I think the server is getting switch, I have posted two times and nothing showing up. Maybe I have been tagged!