| Author |
Message |
Jack Perry (Jpwinks) (66.174.6.205)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 21, 2003 - 9:01 pm: | |
To my esteemed and loyal Nuts; I once again come to you and ask of your expertise and solicit opines.
I am currently suffering an intermittent difficulty with the forward leveling feature on my 83 m9 (kneeling). It initially acted up around 1 out of every 20 starts, wherein the bellows would not automatically inflate completely to the proper height (although all warning lights and buzzers would go off indicating an okay situation); if I manually dumped the air at this point (using the kneeling switch on the control panel) and forced the coach to kneel and then manually forced the bellows to fill it would automatically adjust to the proper height without over inflating. The problem is this…I am no longer able to “cycle” and eliminate the under inflated bellows.
This is what I know:
1. I have used the bible “DaBook” to locate all related components without fail.
2. I have diagnosed that the kneeling switch (on panel) is okay and working.
3. I have diagnosed that the solenoid that is controlled by the kneeling switch is okay and working.
4. I have diagnosed that there are no major leaks or hissing noises in the system.
5. I have manually bled the air tanks to eliminate moisture/contaminates.
6. I have diagnosed that all other components that run on air are okay and working.
7. I have diagnosed that the compressor is okay and working fine.
Questions I have:
1. Is it possible that something is inherently wrong with/within the leveling valve?
2. If so, is there a rebuild kit? Or does it make more sense to purchase new?
3. I believe to have looked at and evaluated all the related components, have I missed something?
4. Is there anything else that I can diagnose before pulling the leveling valve?
Summary:
By all accounts (mechanical / electrical / warning systems) the forward leveling system appears to be operating without a hitch…except IT”S NOT!
I look forward to any input that you can afford.
Jpwinks
83 MCI m9
P.S. This has been cross posted for the Nuts that don't frequent this board. |
FAST FRED (63.234.21.126)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 22, 2003 - 5:26 am: | |
Am more familiar with GM leveling valves and there only about $40.00.Mci shouldn't be that different in cost.
The leveling valves are a high wear item and seldom last many decades , as the rest of the coach gear seems to do.
Might just be worth a change out , as part of your problem solving,
FAST FRED |
bruceki (12.228.106.43)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 22, 2003 - 5:38 am: | |
I've had intermittent problems with the front air bags inflating when I am initially airing up. It airs up, but the front air bags are not inflated at all. I then kick the brake a few times, and this seems to free up whatever it is that is not working, and bags then inflate.
My solution to this is to switch to a strictly manual air bag inflation scheme, so I can level the coach with them. I've done some inflation tests, and the air beam/bags themselves will hold air for 7 to 10 days where my bus usually airs out in 15 or 20 hours.
Next time you have this problem, try kicking hte brake pedal a bit. Five or six full pushes seems to do it for me.
Bruce |
Doug Dickinson (Dougd470) (65.161.188.11)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 22, 2003 - 10:24 am: | |
If you have a kneeling coach, your problem probably is in the kneeling system, not the leveling system (although they are tied together). I had a problem with mine causing the brakes to lock (a safety interlock feature) when my kneeling function malfunctioned.
Most of us have bypassed the kneeling function since it really doesn't do much for us in a conversion sense. That solved all my problems with suspension.
FWIW
Doug
St Louis 83 MC9 |
Geoff (Geoff) (66.238.120.42)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 22, 2003 - 11:47 am: | |
Keeping the kneeling feature of the bus gives you half of a manual over automatic leveling system if you modify the system. The reason most people get rid of their kneeling valves is not because they aren't needed or nice to have, but because the worn out Skinner valves allow the bus to lose air out of the air bags when parked (locking up the brakes is another problem). When I built my manual over automatic leveling system I kept the kneeling feature but hooked it up to my new solenoids (no brake interlock). This allows my wife (with the bad knee) to get on and off the bus easier.
As far as the original question, it sounds like Jack is not getting enough air pressure to the leveling valve to air up the front bags. It is up to him to figure out why there is not enough pressure, the kneeling valves should not effect the automatic lever, and I doubt the leveling valve itself is plugged up (but it could be, you just have to get dirty and look).
--Geoff
'82 RTS CA |
jpwinks (66.174.3.205)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 23, 2003 - 11:20 pm: | |
Thank you for the input.
I will attempt to start tearing this system down over the next few days.
I think the problem is primarily in the skinner valve and there is a very good chance that there is some wear and tear in the leveling valve.
I've decided to eliminate the kneeling feature (I have 6 kids [#7 on the way] that can crawl straight up a flag pole in less than 3 seconds; I don’t think 4 or 6 inches more on the first step will slow them down for a nanosecond); as well I would like to eliminate the relationship between the brakes, the entrance door, and the automatic step. In addition, I've decided to R&R the leveling valve (FF is about right at $40 and it's not worth having to crawl under this behemoth again...at least not for this reason).
I will keep you abreast as I proceed.
Thank you,
Jpwinks
83MCI m9 |