[Richard]

I am posting this for Mike Ginn. 

Today, he had a very bizzare occurence. He had to make a hard brake, then he noticed that the passenger side rear was rubbing on the fender skirt. He made it to the shoulder, examined the situation, and the coach remained on the tire with the engine running. 

He turned the engine off, and a few minutes later, restarted the engine. The coach returned to normal ride height. 

The coach has remained level for over a week so that sort of rules out a leaking air bag. 

The engine builds 120 psi and easily maintains it. 

Pictures of the ride height control valve don't show anything obvious. 

Replication of a hard stop in a parking lot, did not cause a second occurence. 

Mike is coming by tomorrow, and if you have any ideas about what to look at or any kind of diagnostic to run, then please speak up.

[folivier]

Could the ride height valve have gotten hung up temporarily from the hard stop? Then came back to normal?

[Land Yacht]

Thanks Richard for the post and help!

To add to the story. I never felt anything wrong with the coach driving, but we were going slow in Heavy traffic after a rapid stop. I just saw smoke in the mirror, and my wife said it was the tire. When I got to the shoulder, I was pretty sure it was a tire since all readings on my vmsPC were normal, I left the bus running. Once outside I saw the right rear sitting on the drive tire. I could not hear any air leaks with engine running. I walked to left side and it was at drive height. I turned off the engine to further assess the situation and decided to restart to see if it would reset since I could not hear air with engine off either. The coach returned to proper ride height and to proper air supply 125psi. I shutdown the engine again, and could hear no air leaks. After inspecting tire damage, it was holding air and no groove was deeper than tread. I could see an exit sign ahead and decided to go slowly down the shoulder to the exit and get off I-10. Fortunate for us there was a Walmart a mile of the interstate.

I consulted with Richard and sent pictures of ride height control valve on passenger side, looked normal.

I disconnected truck and my wife followed me with our phones connected so she could quickly tell me if the tire was smoking again. We drove without issue for over 200 miles but never encountered another rapid stop due to traffic backed up on interstate.

Background.
Last August, I stopped, shut down engine and the right rear sat down all the way within minutes. It aired up fine when I started the coach. I rebuilt the dump valve solenoids on the rear 6 pack. No other occurrences.

Also as Richard said, the coach had been in level mode with rear up for 10-12 days prior to departure today.

I just had to move as Lowe’s would not let us overnight, and again no issues moving around parking lots

Thoughts appreciated.

Mike

[Land Yacht]

Update: just after crawling in bed, I heard creaking noises. It took a couple of minutes but the HWH panel finally proved my suspicion, the right rear was leaking down. I let the system level left-right by exhausting air, then try to lower the front to match the rear. However, the front could go no further, so the system tried to raise the rear. When the supply reached 60 psi and the 110v compressor not making any significant headway. I turned the HWH off, and let the compressor pump to 100 psi and shut off.

This situation does seem to happen often, sometimes it stays level for hours, sometimes for days. Like I stated above, it held fine for 10 days before starting this trip. I never worried too much about this because it seemed intermittent and only when leveling, but now wondering if this was also cause of today’s misadventure?

Mike

We will start the bus in the morning and hopefully it comes up to proper ride height.

[Richard]

A ha!

I have seen this before, and if I hadn't witnessed it, would have said NO WAY. Bill Johnson @"bikestuff" knows this one all too well. One of the air bags on that side is breaking it's seal with the bottom horn. It will reseat, but the unseating can be unpredictable.

[Chester Stone]

As to the smoking tire, twice in five years I had to make an emergency stop. The tag wheels on my 2001 do not have the ABS braking system and emergency stops lock the tag brakes causing a lot of smoke and flat spots on the tires. Had to replace the tires both times.
As to the major noise heard while in bed, that was probably due to the drive axle brakes adjusting or slipping when the height of the coach changes.
Since the left rear sagging does not replicate, I suspect wiring or something in six pack, a sticking height control valve, but I really have not good idea.

[Richard]

It is confirmed that the aft air bag on the drive axle burped it's seal. The coach replicated the pancaking on the wheel in my driveway. It did exactly what @"bikestuff" 's coach did. Soapy water and the Infinicon positively identified the leak at the juncture of the air bag and the lower horn.

We tried getting the bag to reseal by airing up the coach all the way, but there is still a small leak.

[Land Yacht]

Thanks to Richard and Bill for the tremendous knowledge, know how and help! Interestingly, I replaced the left drive air bags 18 months ago and they are Firestone. The failing bags are only 3-4 years old and are Goodyear. Bill’s research and personal experience showed a different design on the bead. He ordered Firestone’s but has not installed. I will be ordering 2 new Firestone’s like what is on the left side and working fine.

Again, thanks to Richard for diagnosing the issue, and teaching me how, so maybe I can do in the future.

Mike

[encantotom]

i have a twist on this issue. i recently acquired coach 526, a 99.

when i raise the suspension up, their is a loud air noise that i traced to the drivers side tag airbag coming from the bottom plate. after it settles about 3/4 inch on rideheight, the whoosing stops. it does still very slowly leak down.

in talking with bill and richard, i think it is a similar issue to what is discussed here. it appears to be a relatively new goodyear bag. as the other side is an older firestone. so i will replace both.

issues is getting the bags. over the last year or so, firestone has stopped making the bag, and i think so has goodyear. i have called a zillion places. the ridewell bag is what newell still carries for it and it is almost twice the price of what it would be if goodyear still made them. i called ridewell and they have stock so the local fleetpride is getting aprice for me.

tom

[encantotom]

i found 2 goodyear bags. 295 bucks shipped.

one they have now, the other in a month.

tom