Community Forums

szwirn · 05-11-2013, 07:56 AM

The drive line brake on my 2003 HR ambassador keeps getting out of adjustment. I've adjusted it several times and am now out of adjustment. There is no logical reason for the pads to be wearing other than the brake is dragging. The brake is air actuated. Anybody know anything about these and where I would start with a diagnosis. The air pressure gauges on my dash fluctuated between 100 and 110 while i'm driving. I'm taking the shoes off and getting them relined. I'll also remove the air drum and have it checked/rebuilt.

Mike Canter · 05-11-2013, 09:29 AM

Couple of questions....
1. Are you talking about the drive axle brakes or a parking brake located on the driveshaft?
2. Are these brakes that are dragging shoe/drum brakes or disc brakes because you say both "pads" and "drum" which is two different types of brakes.

szwirn · 05-12-2013, 07:19 AM

Hi and thanks for responding, the brake is a drum with shoes. It is mounted to the rear of the Allison transmission and connects directly to the drive shaft.

Mike Canter · 05-12-2013, 07:24 AM

That is your parking brake. If it is dragging or coming on without you commanding it then you should first check for an air leak on that portion of the air system which runs from and includes the button assemble to activate in in the cockpit, the air line to the brake and the brake activator. Time to get some soapy solution on everything.