[Richard]

Jon, the fact the coach will lower doesn't really point to frozen suspension in my mind. That doesn't make sense that a bushing or radius arm would freeze in one direction of rotation.

If you put a pair of twenty ton bottle jacks under the rear hitch you can raise the coach without a tremendous effort. I would try to mechanically raise it before I took the suspension apart.

One thing is unclear to me. When you say it won't raise, can you define that it terms of how high the wheel well arch is above the tire?

Does the front raise on that side? Is the coach twisted when that happens?

I am assuming the coach is on level ground.

Give our love to Alie.

[77newell]

Richard: cool questions you do ask. I'm grateful for them.

Here is what I've noticed. With the shock disconnected and the air bags empty and the rear of the coach sitting on the down stops (vertical metal posts on the top of the rear axle below the main frame members, this limits how far the rear can drop). When I add air to the rear rear bags the right side rises starting at about 100psi and continues to rise until I shut off the air when the bags have risen as much as is prudent (fender well opening is several inches above the tires). The left side very slowly rises about 1/2-3/4 of an inch and then stops even as the air pressure rises to 110+psi. Yes, this puts twist in the coach. If I start from full down and use the HWH panel to raise the left side the front comes up and the rear acts as I just described.

When the gauge I've installed on the output of the left rear 6-pack shows 110psi (knowing the right only takes just over 100psi to fully rise), I shut the air off at the 6-pack, crawl under the coach and the left bags seem to have at least as much rigidity as the right side and probably more. If I then place a hydraulic jack under the frame at the front of the torque tubes on the left side and jack it up, it takes a fairly small effort on the 20 ton jack to raise the frame 3-4 inches. This is where it gets weird; when I then drop the jack the coach follows it back down, no air was added or released. I hear no noises while all this is going on. There is nothing holding up the frame from the axle except the air bags and any resistance in the ends of the torque arms. Given all this, it's as if the coach has gained several thousand pounds on the left rear corner, with that weight exceeding what the air bags can support, but only when parked. Going down the road during the time I've had this issue, the ride height is fine. I'm beginning to worry I've got early onset stupidity, that I'm missing something so obvious that the eventual solution will embarrass the heck out of me - duhh!

If you want me to try something specific just describe it and I'll tell you what results. I appreciate any help I can get.

Alie says: Hi y'all". I guess the time we spent in Memphis rubbed off on her.

[MrE]

I know this sounds really stupid, but have you switched the airbags from the left side to the right side? It sounds like everything else is working the same, could it just be a defective air bag?

[Fulltiming]

The statement that makes me dismiss many areas, including the airbag is

Going down the road during the time I've had this issue, the ride height is fine.

What changes when you switch from RIDE mode to LEVEL mode is different valves on the six pack are put into play, the ride height valves are taken out of the equation and the HWH "brain" (assuming this is a HWH auto leveling system) takes over using the level disk in the center of the bay.

[Chester Stone]

This may be way off base, but I am intrigued that the ride mode works perfectly. Could it be that when it is put into level mode, the right front goes up too much thereby putting extra weight on the left rear? It this is the case, then I would concentrate on the level air bag valve on the right front. The only thing that changes between ride and level modes is the front valves which switch from the center valve to the two outside valves. Just guessing.

[Yachts]

Has anyone checked the leveliing switch in the storage bay. I believe it is Mercury based. If it's not level it would never correctly level the coach.

[Richard]

Jon, has it always done this, or did it behave normally at some previous time?

You haven't changed air bags have you ? A different model air bag side to side would explain what you are seeing. The lifting force being a direct function of the diameter of air bag and the air pressure.

Is it possible the front air bag on the low side is not being inflated? A bad raise solenoid valve on the low side should be checked. Perhaps we are looking at the wrong end.

[77newell]

Richard: great questions!  

It has been fine, until we arrived in Florida in February, or maybe just before that. No new parts in the system just preceding the appearance of this problem.  The front rises normally.  The bags on the two sides of the rear appear to be identical in size and vintage.

The weight of the back so overpowers the back that wherever the back goes the front follows.

[77newell]

Marc: I generally don't use the auto level feature. In diagnosing what is going on I've sometimes individually powered the 6-pack solenoids. The solenoids are performing as intended.

[folivier]

Rather than switching airbags why not swap the airlines to the airbags and see if the problem follows the swap?
Also could there be a restriction in that airline to the airbag?