Norgren venting opening leak

[georgiapeachinc]

Thanks Mark. That was going to be my first call to Prevost.

[georgiapeachinc]

I got the entire valve manifold from Prevost and replaced it yesterday. My thinking is when one goes bad more will follow. This solved the problem and it now works better than ever. I was a little concerned finding oil inside these valves which means I may have an air compressor going bad. I'm going to the shop for a yearly inspection and will have them check that along with any evidence of oil in the system. I don't see any oil build up from the air dryer port, which is one of the indicators. Last time air tanks were drained there was nothing and that was maybe 2000 miles ago.

[georgiapeachinc]

Up date on this issue. After replacing the bank of valves yesterday and cycling through the low level and road sequence with perfect action. I set it into low level and quit for the day, everything was fine. Another issue arose. Started up the coach and it did the same thing before I replaced the valves. Rear comes up and the front did not. got the front to rise in manual mode and then everything went hay wire. Switched to low level and the bus came down only on the right side. Cannot lower the left side in manual. After shutting the bus of, ignition off the valve next to the bank of five valves continually looses air and the front squats all the way to the ground. I suspect the valve for the left rear is not working. That would be the set of valves in the left side looking into the compartment. I'm out of ideas on this. Thoughts anyone?

[Fratto]

Can you send a picture of the compartment and the valve that you are talking about?

[georgiapeachinc]

This first picture shows the bank of 5 valves I replaced To the left of those valves are two valves , one on top that you can't see. The valve below is now leaking when the key is off and draws all the air out of the tank except for the main coach tanks. I removed that valve took it apart and found an O ring that was shot. There are 2 O rings in there. I have several O ring kits and nothing matches. On top of that there is an inner O ring that only God can replace, its a special deal. So I'm sure this is part of the problem but I think it goes farther than that. In the second picture are the valves that control the left and right rear height. The left one ( Left side of the coach, drivers side) does not dump in manual. So I suspect this may also be a problem.
I'm at the point where I am going to order those two valves and replace them. All the switches work and there is power going to everything.

I read back to the beginning of this article with all of Joe's input. This sounds exactly what he was describing. Glad this happened in my garage and not out on the highway!!

Your thoughts are much appreciated. I have been in the trucking business for 40 years and fixed a boat load of air problems but this stuff is hard to wrap your head around.

[PrevostNewbie]

Chris, I would stop just replacing everything and isolate the problem. The Bus air logic is fairly simple if you sit down and study it. Do you have a pneumatic schematic for your bus build?

[georgiapeachinc]

Too late for replacing parts. The lower valve on the back wall which is the 3 way, 2 position valve has a bad O ring. Unfortunately, the two O rings inside I can't match up with my extensive selection of O rings. furthermore, one of the O rings is special. I have called Norgren, Prevost and Liberty and these valves are popular and backordered. Norgren estimates 10 weeks. At this point the coach sits huddled in my garage.

[Fratto]

Chris, I sent you a private message. Call me if you have time.

Have a great weekend.

[Gil_J]

In case you didn't know, Liberty modifies the Prevost suspension air system. They add a second air control valve to the front that you pictured. It runs parallel to the one Prevost installed servicing the 2 5-port, 3-way Norgren valves between the drive axle. You'll likely find a capped hose on one of the 5-port, 3-way valves that would have interconnected the supply line between these two valves. If one of the forward pair of valves was bad and couldn't be replaced, you could use just one of them. Just tee the 2 lines headed to the drive axle. When you can get a new valve, just put it back to the way Liberty did it.

[georgiapeachinc]

Thanks Gil. Fortunately I found that particular valve and it is on its way. I dug deep to find the specs on the other valve and Prevost or the OEM wont give me the specs. I found another valve that is the same but before I bought it I would need to be sure it would work. I sent you a link in your email. Thanks!