Norgren venting opening leak

[Fratto]

Good Morning and Happy 2021~

The lower norgren in the drivers bay is leaking air out of the bottom discharge or vent opening. This valve appears to be serving accessory things like:
Optional kneeling
Door lock
Drivers seat
Air horns
Etc.

I assume that this is a valve failure not a control issue? Anything I need to know before I replace my first one?

Also, since these accessories have their own control, what is the valve doing? Why not just feed all of these things from a manifold? Or is the kneeling option being used as part of the HWH leveling system?

Thanks!

[PrevostNewbie]

Are you saying the lower valve (bottom of stack) in the bank of 5? Those are the Level low system. Or is it one of the stand alone valves?

[Fratto]

It is the valve circled in red. The leaking discharge port has the red line pointing to it.

[PrevostNewbie]

On my Bus that is the Air Control and Exhaust Valve. The port you are pointing to is the air Exhaust port for Level Low. If i want to dump the air or lower the bus, the air exhausts there. Air can escape from that port if either the valve is shifted or partially shifted, or leaking. The air supply for that valve comes from the valve above it. if the dump switch is on or you are lowering the bus. This is a good exercise, we can learn together.

[Fratto]

Thanks Mike. I will confirm that this valve is operating like yours in the next couple of days. In the mean time, my valve is discharging even with the level low in drive. You can hear it when you turn off the diesel and it continues until the auxiliary air pressure goes to 0.

[PrevostNewbie]

If it's a slow air leak the spool is shifted partially or the seals are leaking. I just aired up my bus and soaped the ports and no leaks. next i asked someone to push the down button on the Prevost Level low and air came rushing out of that port (port 3) . When you dump air does it rush out of that port like it should? The air supply for that valve is the one above it. It's a spring return single pilot valve. When dumping air, the spool is in the spring shifted position. When you want to manually raise the bus up, the air pilot signal shifts the spool over. This pilot signal comes from the top valve and whtever position you are in at Prevost level low. The prevost level low selector switch will select one of the norgrens in the bank depending on which position. Top in the bank is Air Control & Exhaust, second down is Front Control, Third down, Middle is Drive, 4th down is Rear Right control, Last Valve is Rear left Control.