GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy P12 Chassis 🢒 Brakes 🢒 Park Brake 🢒 Parking Brake Pump Replacement

Removal Procedure

    Notice: When replacing any hydraulic components, the hydraulic system should be flushed with Dexron® III transmission fluid. This is to ensure that the hydraulic system is free of contaminants such as metal particles that may have been circulated through the system as a result of a component failure.

  1. Move the shift lever to park (P) and apply the parking brake.
  2. Position a drain pan to catch the fluid that leaks out. Do not reuse the old fluid.

    3. Object Number: 258761 Size: SH
  3. Remove the parking brake pump motor switch assembly and pressure indicator electrical connectors, and remove the switches.
  4. Remove the pump motor connectors.

    5. Object Number: 258754 Size: SH
  5. Remove the hydraulic pipe from the pump assembly connection.

    6. Object Number: 258762 Size: SH
  6. Remove the screw and washer which holds the pipe to the cross member bracket, if required.
  7. Remove the pipe, if required.

    8. Object Number: 258745 Size: SH
  8. Remove the parking brake pump assembly mounting nuts.
  9. Remove the parking brake pump and bracket assembly.
  10. Disconnect the harness from the bracket.
  11. Remove the pump assembly from the brackets.

Installation Procedure

    Object Number: 258745 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  1. Install the pump assembly to the brackets.

    2. Tighten
    Tighten the bracket mounting bolts to 36 N·m (27 lb ft).

  2. Position the parking brake pump assembly.
  3. Install the parking brake pump assembly cross member mounting nuts.

    4. Tighten
    Tighten parking brake pump assembly mounting nuts to 25 N·m (18 lb ft).

  4. Install the pump assembly bracket nut.

    5. Tighten
    Tighten the bracket nut to 50 N·m (37 lb ft).


    Object Number: 258762 Size: SH
  5. Install the parking brake hydraulic pipe fitting to the pump.

    6. Tighten
    Tighten the hydraulic pipe fitting to 16 N·m (12 lb ft).

  6. Fasten the hydraulic pipe to the cross member bracket, if removed.

    7. Tighten
    Tighten the screw and the washer to 24 N·m (18 lb ft).


    Object Number: 258761 Size: SH
  7. Install the pressure indicator and pump motor switches.

    8. Tighten
    Tighten the switches to 11 N·m (97 lb in).

  8. Install the connectors.

    9. Cycle the system at least six times. Turn the ignition switch to ON and move the shift lever from park (P) to neutral (N).

  9. Check the fluid level. Refer to Checking and Adding Park Brake Fluid .
  10. Check the operation of the parking brake. Refer to Hydraulic Park Brake Diagnostic (Inoperative/Does Not Release) .