09-24-2017, 09:19 AM
Gang,
This is a follow-up to the original post. First of all thanks for all the input. It was very helpful and allowed me to learn much more about my leveling system. And as with most of my stories, the result is a good news / bad news scenario. (My brother says there is no bad news...it is only how I choose to handle it :/)
The good news is that the problem has gone away. The bad news is the problem has gone away without a complete understanding about where it went.
Since I first posted this thread, I did two things that may have affected the answer. First, I replaced all the height control valves. I also replaced the differential lockup valve. The HCVs were original to the coach (2003 with 240000 miles), and I just wanted to replace them for general purposes. The diff lockup solenoid valve was replaced because it would randomly start venting air (lots of air) for no apparent reason. the valve body was mounted with the exhaust up and this allowed grit to enter the valve.
With these two changes, I cannot replicate the coach just sitting down in the back with the key off and auto-level off.
My gut feeling is that the problem was related to the diff-lockup solenoid. I am thinking that when it decided to vent all the air out of the system for some reason, the rear airbags decided to play along and also deflate. There is no good reason to think this...but when I heard the diff lockup solenoid start leaking, it sounded just like the few times I was where I could hear the bags deflate. (Remember this was not a slow leak, but a rapid deflation).
So, the question I am left with is ... What could cause the rear air bags to deflate (left and right) when 1) Key off, auto level off 2) No air in the system 3) Coach is something less than travel height in back?
I will continue to try to isolate the issue and will report back if I develop new information.
Thanks again for the help!
ps. I don't know if I said this before, but I could not cause the issue when plugged into shop air.
This is a follow-up to the original post. First of all thanks for all the input. It was very helpful and allowed me to learn much more about my leveling system. And as with most of my stories, the result is a good news / bad news scenario. (My brother says there is no bad news...it is only how I choose to handle it :/)
The good news is that the problem has gone away. The bad news is the problem has gone away without a complete understanding about where it went.
Since I first posted this thread, I did two things that may have affected the answer. First, I replaced all the height control valves. I also replaced the differential lockup valve. The HCVs were original to the coach (2003 with 240000 miles), and I just wanted to replace them for general purposes. The diff lockup solenoid valve was replaced because it would randomly start venting air (lots of air) for no apparent reason. the valve body was mounted with the exhaust up and this allowed grit to enter the valve.
With these two changes, I cannot replicate the coach just sitting down in the back with the key off and auto-level off.
My gut feeling is that the problem was related to the diff-lockup solenoid. I am thinking that when it decided to vent all the air out of the system for some reason, the rear airbags decided to play along and also deflate. There is no good reason to think this...but when I heard the diff lockup solenoid start leaking, it sounded just like the few times I was where I could hear the bags deflate. (Remember this was not a slow leak, but a rapid deflation).
So, the question I am left with is ... What could cause the rear air bags to deflate (left and right) when 1) Key off, auto level off 2) No air in the system 3) Coach is something less than travel height in back?
I will continue to try to isolate the issue and will report back if I develop new information.
Thanks again for the help!
ps. I don't know if I said this before, but I could not cause the issue when plugged into shop air.
Bill Johnson
Birmingham, Alabama