Some Mornings, Hard as a Rock, Others, Limp...

[GDeen]

and floppy - my belt tensioners that is. When I bought the bus from Steve, the belts would stay tight for weeks on end. During a trip in July, I noticed one morning when checking the engine bay they were down on air and the belts were floppy. Now it seems to come and go.

Would like to find the problem. Any ideas given the symptoms? I have soap tested all the bellows and connectors running to them in plain view. No leaks. Need to dig deeper and am not too up on the air system yet.

[Pete]

Gordon, check the belt tension valve itself and the connections to it. I had the same problem, and we found it to be the problem. Jim Keller and I found it using a listening device that Roger had during the Titusville get together. We tightened the connections and solved the problem. I later changed the valve itself, and have not had the problem since. Hope you find the same.

[Jon Wehrenberg]

What Pete said. Plus finding a leak in the bellows is tough. You not only cannot see all around them, but worse, you cannot get soapy stuff all around them either. You can use my stethoscope and ultrasonic leak detector in OKC. (If you can stand the abuse from the multitude, not that a POG member would break your chops.)

Can we assume that your aux air pressure remains up while the belt tensioners lose air? If not, the problem may not be the tensioners, but a leak in the aux system.

[GDeen]

Alright, thanks guys - will start there. Aux air does stay up.

[truk4u]

If aux air stays up, then there is a check valve to isolate the bellows! I had one on my Marathon. Usually, limp belts are the tell tale sign of aux air leaks.

[HarborBus]

Our bus had the same problem when I bought it but mine would leak down in approx 90 seconds. It took Marathon a little over an hour to find the problem. The leak was in the line going to the bellows under the pump. It was hard to find because it was under a clamp which is what caused the leak in the first place.

[Richard Barnes]

I had the same problem and discovered that the auxilary air compressor would sometimes come on and sometimes not. The pressure switch was the culprit and was sticking in one position or the other. I'd get up one day and the belts would be tight and in a few days they would be loose. Cleaning the contacts seemed to work for me. Compressor now works fine and cycles on and off properly.

Have you checked that out yet? On my coach its in the front compartment under the drivers seat - a gray color plastic housing with cap nut in the center to hold the cover on with 110 wiring and an air line going into it.

[GDeen]

Richard, you know it did occur to me that something like this could be going on. Told Jon that the air is staying up, but I do now recall seeing my pressure down some at one time on the aux air. Am going to spend some time at the bus barn in the morning and will see what I can figure out.

[Jon Wehrenberg]

Gordon, The ability to isolate the problem is dependent upon whether the leak is isolated to the aux system, or just the bellows portion of the aux system.

With a check valve the aux system can lose air, but the bellows should retain air. I do not know if all coaches have a check valve, or if that is converter installed.

If your aux system loses air you have to isolate the leak. Since every converter is different advice on solving that problem on my Liberty is unlikely to be much help on your Marathon. But clearly, step one is to define the problem by monitoring to see if you are losing aux air or bellows air or both.