Title: Inspect the tractor protection valve.
Course: Diesel Equipment Technology II (20107-II) > Section: Brakes: Servicing Air Brakes

Inspection should include

- chocking the wheels before beginning
- starting the engine to build air pressure to 120 psi
- turning the engine off and listening for air leaks
- creating an air leak in the trailer air supply circuit.

ASE 1: III. Brakes: B. Air Brakes: Air Supply and Service Systems (P-1)

Process/Skill Questions:

- What is the purpose of the tractor protection valve?
- How long should it take to build the air pressure?

- What might cause a valve to leak when released?