Thanks Mark. That was going to be my first call to Prevost.
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Thanks Mark. That was going to be my first call to Prevost.
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.
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?
Can you send a picture of the compartment and the valve that you are talking about?
http://forum.prevostownersgroup.com/...id=18383&stc=1http://forum.prevostownersgroup.com/...id=18384&stc=1
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.
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?
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.
Chris, I sent you a private message. Call me if you have time.
Have a great weekend.
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.
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!
After looking high and low for a new valve and technical information regarding the lower valve on the firewall (K910026) I called the company in Canada that distributes the valve for Prevost. They have that valve back ordered with no idea when Norgren will ship any and they don't have any technical data on the valve. I determined that this valve may work https://www.norgren.com/us/en/detail/k41ea00ks1ka2 but it has a slightly different internal part. I'm not sure if I want to experiment with replacing it but at this point I only have one other choice. Radwell International can repair the valve. They offer no guarantee at $387.85. that includes a rush of $100.00 to have it back in 10 days. I'm on a waiting list to get the part from Prevost in Sommerville, NJ. Liberty Coach is also on a waiting list. I wonder how many people have a coach sitting useless waiting for this part!
Wow! Try these people from a random Firefox search. Also note that on this site they say that the valve is discontinued?
https://www.radwell.com/en-US/Buy/NO...RGREN/K910026/
I may have missed it, but have you talked to Norgren to see if they have a work around or an alternate part?
What are your symptoms that lead you towards this valve being bad?
I spoke to Radwell as I mentioned they can rebuild it but they do not have that valve in stock. To answer mikes question. The lower valve that I need was leaking from the port. The other valve that I ordered for the left rear (K910060) that I received has the exact same valve body with a different end on it that looks like it can be swapped out if it has no seal damage. I will take some pictures and post them here later. I'm going to tackle the job today and see where I wind up.
I replaced the Norgren valve in the front (K910060) for the left rear leveling. The valve bodies are the same as the lower valve (K910026) on the back wall, this is the valve that is unavailable for 2 months.. I was hoping that the spool would be the same in both valve bodies but it is not. My theory was if it was the same I would get another K910060 and swap the ends and be good to go. Unfortunately they are different. Reluctantly I shipped the valve off to Radwell International, LLC in Willingboro, NJ for repair. They have repaired this valve before. At $387.00 for a rush turn around in 4 days, twice the cost of a new one from Prevost. I will follow up on this when I get the repaired valve back and installed.
Another option in the future is to simply rebuilt the valve yourself. Relatively simple. Take pictures are you go. Wipe out the interior with brake-clean or similar product. Either replace the O-rings or lube them with some vasaline prior to reassembly. I've saved several Norgrens from the trash heap using this technique.
Joe,
Thanks for the advice. I have changed o rings on many things but the barrel on this valve has 2 o rings that look more like a button with a hole in the middle, nearly impossible to remove without damage; which I discovered. I looked low and high for a replacement kit. Found something that might have worked on Amazon but they never shipped it. This particular barrel that floats inside the manifold looks as though it comes apart to replace the o rings. Without proper equipment I have no idea how you could stretch that o ring over the barrel without damaging it. Good news is Radwell contacted me and said they can repair the valve after looking at it. This company has 3-D printers and a serious machine shop so I assume they could probably rebuild the valve from the ground up if they had to. Additionally they give a 1 year warranty on the repair.
I wish it was simply replacing a few o rings from the multiple kits I have but no such luck! If you have any details on replacing o rings on this particular valve I would be curious!
I am not an o-ring expert in any definition. If it's not an easy 'just lube it', or 'just replace it', then i'm out of my skill bucket fast.
I'm been amazed at the number of times i've gotten old things to work by just cleaning and adding some lubrication. But as you state, this doesn't always work.
Keep us posted in progress.
Radwell contacted me and said the valve is repairable and should have it back in a week. There are going to be a lot of people going the rebuild route if I get my coach off the floor! I can't guess how many coaches are waiting for this valve!
Radwell International repaired and shipped my valve back in a week. I installed it along with the new valve above the repaired one and all is working perfectly. I also located the source of the oil that was going through the valves that destroyed all of the o-rings. The auxiliary air compressor was the culprit. I disconnected the main line from the compressor and shot it full of brake cleaner and let it run for 1/2 hour disconnected. It ran dry with no oil so I buttoned everything up. The oil is a mystery. The auxiliary air compressor was replaced before I got the coach so this sis something I need to investigate.
That is great news. A week is a super turn around time.