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Level Low Solenoid Rack
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You’re right Bob, only good news so far, in chasing aux leaks, I have come across several fittings leaking on the brake air. Now, my brake air holds for days!!!
If I could only get the aux leaks done, and figure out the dropping rear. Just went out there and it’s already dropped 1/2 inch in 2 hours, with the tag raised!
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on dash is it below 75 lb? if so hook your shop air feed up in front compartment where stack is there is a schrader valve in small dryer for stack. take it out(1/4 inch fitting) and put a shop air feed in there…I have had problems with feeding from rear before confusing check valve… Bob
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OK Bob, I’ll try that.
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you being a detail guy. there is something telling them to go down. Almost 2 many things happening at once here with both sides going down equal. After trying supply from front compartment.. possibilities bad signal telling them to go down… electrical?? you can remove that signal source possibility… elect over/ air the signal changes in the stack. the stack is on a common manifold. the selnoids share a common air supply— the sides are seperated by O-rings. yours are old. CK? When you level with the HWH does it stay up days? if so that would elinimate a bunch. If it goes down the same that helps also
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The way I understand the HWH is that it uses the Prevost valves, not it’s own, and it does control the valves for leveling. That may be why I don’t get anything out of the Level Low switches. They are all on 24v. They appear to be the original ones. I’m going to look around in the control box for the HWH, to see if I see anything in there suspicious.
I will be going through the process of elimination (Hopefully) today on the valves., as Jon suggested.
I have also ordered new ones from Prevost, when they get here, I’ll replace them, but in the meantime today, I’m going try and figure out what’s been going on.
I have a pretty quick aux air loss, but I can’t hear anything leaking anywhere, so I’m still looking for that. I know it can be in the pocket doors, step, Gen air bags, engine air bags, (replaced already) TV lift and other places.
I did find a leak on a plastic manifold in the ceiling of the drivers bay, that I will be replacing also.
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Jerry, having been through the process of trying to stay ahead of leaks I have found with each succeeding coach that both Prevost and Liberty had air systems of ever increasing complexity due to greater use of aux air. One thing I have already done and will be doing a lot more of the same is to start adding shut off valves to each individual air system in the aux air total system.
Then your focus in chasing leaks gets more focussed. Turn off all valves, go get a cup of coffee and when you come back open the valves. Any valves that have air rush through them are on circuits with an air leak.
That doesn’t necessarily make chasing leaks easier, but it enables you to stop looking everywhere and allows you to just follow the leaky circuit.
Those valves are on the house circuits all of which originate from a manifold installed by Liberty. I don’t know how other converters set up their distribution of air lines. I haven’t yet added any to the Prevost aux circuits (not the suspension) but I have identified and labeled what all the Prevost circuits are because they also originate from manifold blocks.
I have not and will not do that to the suspension because I do not want to mess with a system that critical, and also because the system tells you where to look for leaks by how the coach leans or drops.
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I’m in shock, are those actually push in fittings!
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I saw that too , all that work and push in fittings, really!!!! LOL !!!!
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Jon: I don’t have a bus yet.
Where in your Liberty is that collection of valves and stuff?
Adding those shutoff valves seems easy and inexpensive … why don’t the converters do that when they build the coach? If something “goes wrong” … it would be so easy to isolate the offending sub-system.
Thanks for all the great descriptions and pictures.
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Even a Royale has comp fittings on those , thought liberty would be gold plated comp fittings!!!!!!!!!!
Mine are in the steering bay…..
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OK you push in fitting guys.
If you take a look at the manifold you will note the fittings are literally side by side, and unless the 90 degree fittings swivel there is no way to get them on the manifold. Send me a link to any compression fittings that swivel and I will change them out…………I’m waiting…………….still no link………………….didn’t think so.
The manifold with the shut off valves is in the steer compartment.
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You are right Jon I did not put mine in a manifold block so I could use comp fittings that was one of the reasons I did it the way I did it , yours looks way cleaner , mine are on each line not all on one block , I put one on every acc line and one big one , on line coming from acc air tank just before norgren filter ……
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I knew that was coming about the Push-ins LOL
Good Idea Jon. I actually put a ball valve just ahead of the aux compressor, just to see if leakage was occuring at the compressor itself…….notta.
Someone before me put 1 in the steer compartment that feeds the step, fold up TV etc. I have turned it off, no difference. I will put additional valves on other aux lines.
New update, I raised the bus up, disconnected completely all solenoids from the valves on the manifold, so the solenoids are completely off, AND, the bus is slowly dropping in the rear again!!!!
Could the middle valve not be holding pressure inside the manifold/valve,and letting the signal to the 5 ports in the rear allow the piston to move? I know they have springs to center the spool, but I don’t know which way the signal is from the center valve, whether it holds pressure or not.
How do the valves work? What does the solenoid do to the stem?
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If it is dropping you have ruled out the HWH.
The Norgren valve can leak through the valve itself so air that is supposed to be blocked can flow (think of a leaky faucet) or it can leak out past the end of the spools and out the end caps. If it is leaking out the end caps from air leaking past the end of the spools, given enough soapy water you will see the bubbles. If it is leaking through the valve you will hear that through an unltrasonic leak detector or if you have a TX bubbler or a gauge to watch system pressure drop you can find those leaks.
Chasing leaks is not for sissies. You got at least one, and maybe more and only through starting at one end or another and then working up or down the system one component and fitting at a time are you going to find the leak.
At this point given all you have gone through I think I would remove the supply line to all 3 air bags on a side from either the first air bag, or the 5 port Norgren and change the fittings so I could pressurize the 3 air bags and measure pressure loss if any. If no loss of pressure the 5 port Norgren would likely be the issue.
Conversely if there was an air loss then I would move to the next air bag in line and measure air loss, if any.
It is a painfully slow process when you are unable to find a leak the easy way, by listening or using soapy water.
I’ve been through it, Tom just went through it, and Hector has almost gone through it to the extent his bus will still not be leaning when the Pyramids are nothing more than a pile of sand.
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All the Norgrens in the rear are new, I guess they could be bad. When I started this, the RR was leaning. Since, I replaced all the valves, and now both sides drop.
Back to the electric solenoid valves………they show no signs of leaking outside them, but maybe, they are leaking inside.
I already checked leakage by unhooking the air bag line from Norgren, and pumping air, which it lost 3 lbs per hour per side, and that was all 3 bags together.
I have not replaced the 2 Norgrens in the steer compartment. I have 1 new one left.
While all this is going on, the front stays up all the time! LOL
I know you guys have had enough of my leaks, but I will continue to narrow it down…..hopefully.
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