RV particulars:
Engine: Cummins 350, Allison
Miles: 40,000
Year: 1997
Break Down Description: (You can add any description of the problem here that you think would help others in understanding the situation and problem.)
Symptoms: Loss of air pressure
Effect: Had to stop before brakes locked up
Cause: Air dryer seal
Outcome: Good Sam Road Service dispatched diesel mechanic who bypassed air dryer to continue trip. Replaced seals when we got home. Told that this is a maintenance item.
Lesson: Put the air dryer on your annual maintenance list.