Front won't go up or down?

[Jon Wehrenberg]

Elliot,

What appears to be happening is when your go to the travel or ride position the center solenoid is functioning as it should allowing aux air to flow through the ride height control valves.

When you go to the manual position and attempt to raise the front it fails because one of the top two solenoid valves or valve coils is failing to function. When you attempt to raise the front manually both of the top two solenoid valves come into play. My guess without getting further details from you is that the second one down is functioning correctly because the bus will go down, but the top one is faulty because it will not go up.

Since it appears the third one down is funtioning as intended don't change that one. It appears the second one down is also OK. So swap the top one with one of the bottom two and see if the problem with the front goes away. If it does you know what part has failed. If that does not solve it report back with details and I will go further into the system but right now my guess is with the solenoid valve or valve coil.

[truk4u]

Elliott,

I'll stay out of this since Jon is helping you, but remember, each assembly has two parts, the coil and valve. If your just swapping the coil and not getting any results, it could be the valve that is bad.

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[HarborBus]

OK Jon I'll try that, I sure wish I had an extra coil and valve on hand.

[Jon Wehrenberg]

OK Jon I'll try that, I sure wish I had an extra coil and valve on hand.

You do. Verify the rear left and right are functioning properly, and if so you know they are working. Use one of them to replace the top one.

Note Tom's post. Start by swapping coils.

[HarborBus]

Yes, I have verified that the right and left rear raise and lower as they are supposed to I have done it several times. So I will use one of those solenoids for in place of the top one. One question, is the auxiliary tank the little pancake tank in the compartment under the seat? If so how do I turn off the aux pump to keep it from trying to refill if I have to replace the valve. My pump for that tank is a 12 volt pump at the back of the generator.

[Jon Wehrenberg]

That's a Marathon question I cannot answer. I presume you can turn off the aux pump and bleed the aux air system down to zero if you have to change the valve and not just the coil. On my coach I have a connection for an air hose in that compartment as well as drain cocks on my pressure regulator bowl so I can dump air in the aux system at either place.

If all you change is the coil that has no impact on air pressure. Unless the Marathon suspension system is different than the Prevost Level Low (apart from HWH) dumping aux air will not change the height of the bus as long as the key is off, but anytime you are working on any part of the bus, either keep your body and all its parts out from beneath the bus, or support the chassis so it cannot drop.

[Kevin Erion]

you can turn that air compressor off at the small round circuit breaker back in the bedroom behind the dark plastic door. Look for the one marked aux air and push it, it should pop out, thats off.