Near-north Ontario, French River | If the maxi sounds 'loose' when you tap it, the spring is broken, but that doesnt necessarily mean the pancake is ruptured.. but if it isnt its just a matter of time. To the OP, I had a ABS valve fail once, when you hit the brakes there was a very audible air leak. Also had a TPV fail once, when you hit the brake pedal there would be a 2-3 second lag until the trail brakes engage, then when you let off they seemed to drag for 2-3 seconds before releasing. New TPV solved that issue. IF its your treadal valve the air leak should be easily audible , even with the engine running. You description of not being able to hold pressure at a stop light tells me you have a blown service chamber. Depending how badly the pancake is torn they can be very audible or almost impossible to hear. Pull the truck in the shop, put shop air to the air tanks, and with the truck OFF, depress the brakes. if you can't hear anything, go from wheel to wheel and physically feel around all the brake chambers and various valves. You've got a major air leak somewhere and shouldn't be driving until its fixed. |
Semi Air Brakes Troubleshooting Questions
