GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC C-Series Medium Duty Truck B7 🢒 Brakes 🢒 Air Brakes 🢒 Air Brake Double Check Valve Leakage Test
  1. Block the wheels.

    2. Object Number: 209561 Size: SH
  2. Remove the valve (2).
  3. Plug the delivery port.
  4. Connect an air supply to one of the supply ports. Apply approximately 861 kPa (125 psi) of air pressure.
  5. Apply a soap solution to the opposite supply port.
  6. Check that the leakage is less than a 25 mm (1 in) bubble in 5 seconds.
  7. If the leakage exceeds these specifications, replace the valve.
  8. Disconnect the air supply.
  9. Repeat steps 4 through 6 on the other supply port.
  10. Shut off and disconnect the air supply.
  11. Unplug the delivery port.
  12. Install the valve (3).
  13. Charge the air supply.
  14. Check the brakes.
  15. Remove the wheel blocks.