Near-north Ontario, French River | Personally I wouldn't look at the brakes themselves( ie the drums, shoes, slacks, air chambers), I'd be looking more at valving on the tractor. TWICE I've had the tractor protection valve go back and both times it caused symptoms like this. Tractor brakes would come on hard, following a couple seconds later by trailer brakes coming on . I really don't know why the TPV was making things act that way, but replacing it solved the problem. Two different trucks but both T-800s. Another thing to try is to get the truck into a quiet area, air it up and shut engine off. Apply the brake pedal and listen for air venting. You could have a quick release valve on the trailer that's venting, and stopping the trailer brakes from activating properly. Either way, get it fixed ASAP because you cause a wreck. I'd hate for tractor brakes to come on hard, and nothing on the trailer,... loaded and on ice. Bad things happen. |
touchy air brakes
