[Peter]

Grizz,

If an new event occurs following a repair you can almost be assured that when the repair was done the technician did something to cause the problem.

Then when you ask the technician about what he did to create the problem he will often get defensive which makes solving the problem more difficult. What you need to begin is to find out how Marathon routed the air lines to the air horn and the seat. If you have diagrams available it will help you trace the lines from the seat back to the source.

It could be anything from a valve that was closed by the tech, to another solenoid whose wires got disconnected, to the tech getting creative and plugging a line because he didn’t think it went anywhere. If your aux system is holding pressure it could be any of the above three items. If you aux system is leaking down it will be a matter of finding where the air is leaking from, and then looking for the line to the seat, and connecting the two.

[Larry]

Grizz,

FYI – If you don’t have Prevost aux air up, you will have no seat air. I thought maybe you were trying to play with the seat while parked. It’s plumbed from the Prevost side and not the Marathon aux. Also, the front button has to be in the up position or air is shut off.

Seat air is above the yellow knob.

Stop knob has to be up for air.

[Jerry]

Thanks! The stop button was moved down and I did not know or think about it.

Thank you so very much, from an old guy who must be losing it!

[AL]

Tom….do you guys generally keep the Bus air and the Aux air separated? I’ve been running with the valve open between them. I seem to get the sense that most people keep them separated..ty

[Tom]

Marathon factory labeled…..

[Liam]

Tom,

The only time I open the valve is to charge the Prevost aux system before starting to allow the aux compressor to bring up the Prevost aux air so the engine belt bellows are pumped up. One reason to keep it closed when the bus is not running is the aux compressor makes a lot of water, so keeping it closed assures the water is within the Marathon system and can be drained via the Marathon aux tank.

On the other hand, I don’t see any reason why it can’t be open during traveling, the Prevost air is dry and clean, providing it is maintained properly.

[Archived]

Tom,

Not sure of all the details.. .but I recently had some issues on the marathon air side and Leon advised to open the valve to get enough PSI to close the slides… he was very clear to run run with it open…. if there was a massive air leak on the house side and it was open could that cause issues for the chassis? Not sure… I just do what I am told. 🙂

Bill

[Fred F.]

Bill,

Generally speaking large air leaks on the house side of a coach are a serious problem for the chassis.

But instead of thinking house leaks, think of it as an accessory or auxiliary system leak. As long as you have an open path from the bus air system to the leak at the very least the engine driven compressor will be working very hard to maintain system pressure if it can. If it cannot then the degree of seriousness ramps up. As long as the coach air system inegrity has been maintained and check valves and protection valves work as intended you can safely drive the coach, because all air produced will remain with the two braking systems as long as the protection valves shuts flow to the aux air system. Once they reach 75 PSI then air will be released to the aux systems and if the brake system pressure drops below 75 then the protection valve shuts.

That is one benefit of being able to control or limit where air can go. Our aux air systems are extensive with plenty of potential places for leaks, some of which can be large. Our main aux system purpose is for our suspensions. If an air bag bursts, there is nothing to prevent the coach from dropping, and also there is no way to shut off air flow to the leak unless you can manually direct air or block air from going to the respective air bag locations.

On the converter side if there is an issue with the house air functions, ideally you should be able to close the air flow to that portion of the aux system also.

I cannot address all slide coaches, but I need air for my slides, not to move them, but to perform certain functions. I need to inflate and deflate the seals. I need to retract and engage slide room pins. All of that is on the aux side of the air systems. Once those functions have been satisfied however I think I could turn off air to the slides if there is a huge leak in that system.

[Dick]

Bill,

I understand what they are saying and following Leon’s advice is the thing to do. I’m on my 6th bus and this Marathon is the only one that doesn’t get all it’s aux air supply from the engine compressor when running. Those other Coaches were designed so the aux compressor wasn’t needed when driving. With the Marathon, you have to leave the aux compressor on while traveling so you have air for the pocket doors, slide, seat, etc. Or, you turn the little yellow knob and combine the aux air with Prevost aux air and not worry about having the compressor on.

Isn’t this stuff fun…..

[Corey]

Thanks for the help…I’ll change my valve to closed the next time I’m down at the barn. I can add this one to my growing list of assists I’ve gotten from my PC tutors….ty