Removal Procedure
- Block the wheels.
 
- Drain all of the air reservoirs. Refer to 
Air Brake Reservoir Draining.
 
Note: Tag the air lines for later installation.
- Remove the air lines at the differential lock pressure protection valve. Refer to 
Hose and Line Replacement - Nylon Push-In Type Fitting.
 
- Remove the following components from the differential lock pressure protection valve:
 
- Remove the differential lock pressure protection valve at the brake pedal bracket.
 
- Inspect the air lines for the following conditions:
 
- Repair or replace the air lines as needed. Refer to 
Hose and Line Replacement - Nylon Push-In Type Fitting.
 
Installation Procedure
- Install the differential lock pressure protection valve at the brake pedal bracket.
 
Caution: Refer to Fastener Caution in the Preface section.
- Install the following components to the differential lock pressure protection valve:
 
Tighten
Tighten the differential lock pressure protection valve nuts to 12 N·m (106 lb in).
- Install the air lines at the differential lock pressure protection valve. Refer to 
Hose and Line Replacement - Nylon Push-In Type Fitting.
 
- Start the engine. Charge the system to the air compressor governor cutout point.
 
- Stop the engine.
 
- Inspect for air leaks using a soap solution.
 
- Remove the wheel blocks.