GM Service Manual Online
For 1990-2009 cars only

Reservoir Replacement - Rear Axle Front Unit GZK

Removal Procedure

  1. Apply the parking brake.
  2. Block the wheels.
  3. Drain all the reservoirs. Refer to Air Brake Reservoir Draining .
  4. Remove the air lines. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .

  5. Object Number: 1487251  Size: SH
  6. Remove the reservoir support strap nuts.
  7. Remove the reservoir support straps from the reservoir supports.
  8. Remove the reservoir.
  9. Clean the air lines and the fittings with a dry cloth.
  10. Clean the inside reservoir with steam or hot water.
  11. Inspect the air lines for the following conditions:
  12. • Damage
    • Cracks
    • Bulges
    • Wear
    • If any of these conditions are present, replace the air lines.
  13. Inspect the reservoir for corrosion or damage.
  14. Replace the reservoir if the reservoir is weakened.
  15. Inspect the reservoir supports and the straps for damage.
  16. Replace the supports and the straps, as needed.

Installation Procedure

  1. Install the reservoir.
  2. Install the reservoir support straps to the reservoir supports.
  3. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1487251  Size: SH
  4. Install the reservoir support strap nuts.
  5. Tighten
    Tighten the rear axle service reservoir support strap front unit nuts to 13 N·m (10 lb ft).

  6. Install the air lines. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .
  7. Start the engine.
  8. Charge the system air pressure to the governor cut-out point.
  9. Stop the engine.
  10. Inspect for leaks with a soap solution. Leakage is not permissible.
  11. Inspect for proper brake operation.
  12. Remove the wheel blocks.

Reservoir Replacement - Rear Axle Front Unit Non-GZK

Removal Procedure

  1. Apply the parking brake.
  2. Block the wheels.
  3. Drain all the reservoirs. Refer to Air Brake Reservoir Draining .
  4. Remove the air lines. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .

  5. Object Number: 1487256  Size: SH
  6. Remove the reservoir support strap nuts.
  7. Remove the reservoir support straps from the reservoir supports.
  8. Remove the reservoir.
  9. Clean the air lines and the fittings with a dry cloth.
  10. Clean the inside reservoir with steam or hot water.
  11. Inspect the air lines for the following conditions:
  12. • Damage
    • Cracks
    • Bulges
    • Wear
    • If any of these conditions are present, replace the air lines.
  13. Inspect the reservoir for corrosion or damage.
  14. Replace the reservoir if the reservoir is weakened.
  15. Inspect the reservoir supports and the straps for damage.
  16. Replace the supports and the straps, as needed.

Installation Procedure

  1. Install the reservoir.
  2. Install the reservoir support straps to the reservoir supports.
  3. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1487256  Size: SH
  4. Install the reservoir support strap nuts.
  5. Tighten
    Tighten the rear axle service reservoir support strap retaining front unit nuts to 13 N·m (10 lb ft).

  6. Install the air lines. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .
  7. Start the engine.
  8. Charge the system air pressure to the governor cut-out point.
  9. Stop the engine.
  10. Inspect for leaks with a soap solution. Leakage is not permissible.
  11. Inspect for proper brake operation.
  12. Remove the wheel blocks.