Aux Air Leak??

[0533]

Thanks Brian,

This might explain why I noticed the noise right after doing a manual leveling of the bus.

When I finish the leveling I leave the switch in the last position I had leveled.

Before I restart the bus I move it back to the ride position, have I done something wrong in this process ,should I leave it in the ride position after I turn off the key??

I will look for your picks and read the other posts. I definitely am not level any longer, will get back.

[0533]

Thanks Brian, very helpful, I will use this as guide, but after I test with a restart of the ride position key on..

[0533]

Some have a single small screw in the center of the electrical "plug" on one end (the part with the wires)

Loosen the screw and wiggle off the plug.

Examine the valve body to discern the way in which it is mechanically mounted to the switch block, and loosen that mounting. (save all screws, as they will be needed for remounting the new valve)

Swing the old valve, still attached to the air, out of the way and mount the new valve to the switch block.

Remove the airline and fitting from the old valve. Install the existing line and fitting to the new valve. (best to have the air off), but could be done in a pinch with air in system (work quickly).

Jim I will follow your suggestions but after I get a replacement part. PS> there is no way that I will be able to do this quickly as all projects are on the job training sessions for me.

Also when I restart the bus am I going to be able to return to normal ride level position?? Is this solenoid that vital a a part to the operation of the bus over the road????

[BrianE]

Bruce, As I mentioned, am not sure why this works but returning the switches to the ride position immediately before shutting off the ignition switch locks the valves in the ride position where they're less likely to leak. The system is deactivated when the ignition switch is off so you can leave the switches in the ride position. The bus will then go to ride height when you make your next startup. At least, that's the way it works on our Liberty

[0533]

I did the re-leveling and the quick shutdown in the road position, and the solenoid is still leaking.

I guess when I finished leveling I left the position switch in the left side position when I turned off the key, this may have contributed to the problem.

I will take the little bugger apart and see if I can clear its little brain.

Thanks,

Bruce

[Jon Wehrenberg]

The solenoids are the coil to which the wires are attached. By energizing the wires the coil becomes a magnet and the magnetic force puills the valve open.

When the coil is de-energized the valve spring closes the valve. When the valve is closed the air pressure in the line that pushes the Norgren valve pneumatic operator is released and spring pressure in the Norgren valve pushes the Norgren valve to its normal position.

The reason I point this out is that there are several failure modes. The most likely is the valve itself leaks at the base. There are two screws (in some cases they are phillips and in others they are #10 torqs. They are under the coil and to access them pull the coil by removing the "c" ring. Tighten them. If that does not do it, remove the valve itself and see if the small "O" ring has been pushed out of place by air pressure.

You will have to do a little detective work to find the offending valve body but if it is a problem isolating the actual leak to a specific body try tightening all of them.

If they are all tight and if you do not find an "O" ring out of place then it is likely the valve itself is leaking. They can be ordered from Prevost and in your hands overnight. If you cannot live without your aux air you may have to go to Lowe's or Home Depot and plug or cap the aux air line feeding the manifold. That line to cap is the one going into the bottom of the manifold. That will allow all other aux air systems to be aired up. Until that leak is fixed and the aux air line to the manifold restored however you cannot travel. If this valve assembly leak is sufficiently large or is associated with a solenoid that affects the ride height you could have problems if you try to drive.

If you must move the coach before you repair the valve the valve that must be working perfectly is the center one in the stack. Make sure that valve is not leaking by swapping it if is is the bad one with any other. Just do not swap coils from their original positions. The center valve in your stack is the one that controls the valving to bring the ride height valves into play.

[0533]

The solenoids are the coil to which the wires are attached. By energizing the wires the coil becomes a magnet and the magnetic force puills the valve open.

When the coil is de-energized the valve spring closes the valve. When the valve is closed the air pressure in the line that pushes the Norgren valve pneumatic operator is released and spring pressure in the Norgren valve pushes the Norgren valve to its normal position.

The reason I point this out is that there are several failure modes. The most likely is the valve itself leaks at the base. There are two screws (in some cases they are phillips and in others they are #10 torqs. They are under the coil and to access them pull the coil by removing the "c" ring. Tighten them. If that does not do it, remove the valve itself and see if the small "O" ring has been pushed out of place by air pressure.

You will have to do a little detective work to find the offending valve body but if it is a problem isolating the actual leak to a specific body try tightening all of them.

If they are all tight and if you do not find an "O" ring out of place then it is likely the valve itself is leaking. They can be ordered from Prevost and in your hands overnight. If you cannot live without your aux air you may have to go to Lowe's or Home Depot and plug or cap the aux air line feeding the manifold. That line to cap is the one going into the bottom of the manifold. That will allow all other aux air systems to be aired up. Until that leak is fixed and the aux air line to the manifold restored however you cannot travel. If this valve assembly leak is sufficiently large or is associated with a solenoid that affects the ride height you could have problems if you try to drive.

If you must move the coach before you repair the valve the valve that must be working perfectly is the center one in the stack. Make sure that valve is not leaking by swapping it if is is the bad one with any other. Just do not swap coils from their original positions. The center valve in your stack is the one that controls the valving to bring the ride height valves into play.

Hi Jon,

The solenoid that appears to be leaking is the bottom one, and it appears to be leaking from the red plastic portion right at the little opening on one side of it at the corner of the red plastic screw, it looks like a relief valve of some type, if I place my finger over the end of the red screw and hold it there for a few seconds it will blow off the over flow valve near the norgren, and makes a sound like it has reached its maximum capacity, this of course happens after I refill the air system, otherwise it has completely run out of aux air.

[Jon Wehrenberg]

I am guessing by your description that valve is not closing. It sounds like it is bad. As stated before Prevost sells the kit to replace the valve. it consists of the valve body and all that is necessary is to remove the defective one and replace it. Two screws and a "C" ring and that's all that is required to be removed and the valve body comes off the manifold.

The new valve will have a new "O" ring to go under it, replace the two screws, put on the coil and the "C" ring and your problem should be solved.

If the converter did not modify the system that should be the valve that controls the left rear. If the leak is not too bad you can drive the coach, but be aware you will be working your compressor to keep up with the leak.

[0533]

I am guessing by your description that valve is not closing. It sounds like it is bad. As stated before Prevost sells the kit to replace the valve. it consists of the valve body and all that is necessary is to remove the defective one and replace it. Two screws and a "C" ring and that's all that is required to be removed and the valve body comes off the manifold.

The new valve will have a new "O" ring to go under it, replace the two screws, put on the coil and the "C" ring and your problem should be solved.

If the converter did not modify the system that should be the valve that controls the left rear. If the leak is not too bad you can drive the coach, but be aware you will be working your compressor to keep up with the leak.

I have successfully repaired the solenoid thanks to all of you. This only proves that it is possible to walk the mechanically challenged through problems successfully.

Here is how I handled it: I first took off the clip, removed the first half then removed the flat and torc screws. The large "O" ring had some kind of crap on it that clearly would open the seal. I took the entire solenoid apart, cleaned each "O" ring including the area where it rests, removed the spring inspected it, cleaned its ends and replaced all parts, pressurized the system and all is good.

PS: all O rings looked as good as new, but the end of the spring near the magnet was very dirty and needed cleaning.

Thanks again.

[truk4u]

Bruce,

Your funky o-rings may be a sign of water/oil in the aux air system that got mixed up with dust and dirt. Make sure you frequently drain the air tanks, service the dryer filter and drain any water out of the small black cannister in the steering bay (assuming you have one). Also, if you have a aux compressor with it's own tank, make sure you drain that one often, I get a little moisture out of mine everytime I drain it and I do it often.