- Charge the air system to full pressure.
- Turn off the engine.
- Apply a soap solution around the cap
of the valve (4).
- Check for soap bubbles indicating leads. A one inch bubble in
three seconds or longer is acceptable.
- Drain the air pressure from the delivery port and remove the air
line connected to the port.
- Apply a soapy solution around the delivery port. A one inch bubble
in five seconds or more is acceptable.
- If excessive leakage is present, replace or overhaul the valve (4).
Refer to
Pressure Protection Valve Replacement
or
Air Brake System Description and Operation
.