GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC C-Series Medium Duty Truck B7 🢒 Brakes 🢒 Air Brakes 🢒 Pressure Protection Valve Leakage Test
  1. Charge the air system to full pressure.
  2. Turn off the engine.

    3. Object Number: 202622 Size: SH
  3. Apply a soap solution around the cap of the valve (4).
  4. Check for soap bubbles indicating leaks. A one inch bubble in three seconds or longer is acceptable.
  5. Drain the air pressure from the delivery port and remove the air line connected to the port.
  6. Apply a soapy solution around the delivery port. A one inch bubble in five seconds or more is acceptable.
  7. If excessive leakage is present, replace the valve (4). Refer to Reservoir Drain Valve Replacement - Front Axle .