GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1998 🢒 Cutlass 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Hydraulic Brake System Flushing

Flushing Procedure

Important: 

   • If evidence of contamination is present in the vehicle's brake fluid, flush the entire brake system using one of the procedures outlined below.
   • After flushing the entire brake system, replace the following rubber components:
      - The brake hose assemblies
      - The master cylinder rubber parts
      - The brake caliper and wheel cylinder boots and seals
      - The hydraulic modulator
      - The ABS solenoids
   • Re-flush the system after all of the rubber components are replaced. Use one of the following procedures outlined below.
   • Once the second flushing procedure has been performed, bleed the entire system. Refer to Hydraulic Brake System Bleeding .
   • Flush the system if any of the following conditions exist:
      - There is a concern that the fluid is contaminated.
      - The fluid contains traces of mineral oil, engine oil, or transmission fluid.

Pressure Flush

Tools Required

J 35589 Bleeding Adapter

Notice: Pressure Bleeding equipment can be used to perform the flush procedure. The pressure bleeding equipment used for flushing must be of the diaphragm type. It must a have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, and other contaminants from entering the hydraulic system.

  1. Clean the fluid reservoir cover and the surrounding areas.
  2. Remove the fluid reservoir cover.
  3. Remove any remaining brake fluid in the reservoir.
  4. Refill the reservoir to the proper level using clean DOT-3 brake fluid.
  5. Install the J 35589 to the brake fluid reservoir.
  6. Install the J 35589 to the pressure bleeding equipment.
  7. Adjust the pressure bleeding equipment to 35-70 kPa (5-10 psi). Wait for approximately 30 seconds in order to ensure that there is no leakage.
  8. Adjust the pressure bleeding equipment to 205-240 kPa (30-35 psi).
  9. Attach a clear plastic hose to the rearward bleeder valve on the hydraulic modulator.

    10. Place the other end of the hose in a container in order to collect the draining brake fluid. Do not submerge the hose end into the fluid.

  10. Slowly open the bleeder valve. Allow the fluid to flow until clean brake fluid flows or until at least 118 ml (4 oz) of fluid is accumulated.
  11. Close the valve.
  12. Attach a clear plastic hose to the forward bleeder valve on the hydraulic modulator.

    13. Place the other end of the hose in a container in order to collect the draining brake fluid. Do not submerge the hose end into the fluid.

  13. Slowly open the bleeder valve. Allow the fluid to flow until clean brake fluid flows or until at least 118 ml (4 oz) of fluid is accumulated.

    14. 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.

  14. Close the valve.

    15. Tighten
    Tighten the hydraulic modulator bleeder valve to 9 N·m (80 lb in).

  15. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

    16. Important: Flush the wheel brakes in the following sequence:

    1. Right rear
    2. Left rear
    3. Right front
    4. Left front

  16. Attach the bleeder hose to the bleeder valve at each wheel.

    17. Place the other end of the hose into a container in order to collect the draining brake fluid. Do not submerge the hose end into the fluid.

  17. Slowly open the bleeder valve and allow the fluid to flow.
  18. Close the valve when the clean brake fluid begins to flow or at least 235 ml (8 oz) of fluid is accumulated.
  19. Lower the vehicle.
  20. Remove the J 35589 .
  21. Replace the following rubber components:
    22. • The brake hose assemblies
    • The master cylinder rubber parts
    • The brake caliper and wheel cylinder boots and seals
    • The hydraulic modulator
    • The ABS solenoids
  22. Repeat the entire pressure flushing procedure one more time.
  23. Inspect the fluid level in the reservoir. Fill the reservoir to the correct level, if necessary.
  24. Install the fluid reservoir cap.
  25. Bleed the entire brake hydraulic system. Refer to Hydraulic Brake System Bleeding

Manual Flush

Tools Required

J 35589 Bleeding Adapter

Important: Use a suitable container and/or shop rags in order to catch the fluid and prevent the fluid from contacting any painted surfaces.

  1. Clean the fluid reservoir cover and the surrounding areas.
  2. Remove the fluid reservoir cover.
  3. Remove any remaining brake fluid in the reservoir.
  4. Refill the reservoir to the proper level using clean DOT-3 brake fluid.
  5. Install the fluid reservoir cover.
  6. Flush the hydraulic modulator using the following steps:
    7. 6.1. Attach a clear plastic bleeder hose to the rearward bleeder valve on the hydraulic modulator.

    Place the other end of the hose in a container in order to collect the draining brake fluid. Do not submerge the hose end into the fluid.

    6.2. Slowly open the rearward bleeder valve ½ to 1 full turn.
    6.3. Depress the brake pedal until the fluid begins to flow.
    6.4. Close the valve and release the brake pedal. Repeat the previous 2 steps until clean brake fluid flows or until at least 118 ml (4 oz) of fluid is accumulated.
    6.5. Attach a clear plastic bleeder hose to the forward bleeder valve on the hydraulic modulator.

    Place the other end of the hose in a container in order to collect the draining brake fluid. Do not submerge the hose end into the fluid.

    6.6. Slowly open the forward bleeder valve ½ to 1 full turn.
    6.7. Depress the brake pedal until the fluid begins to flow.

    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.

    6.8. Close the valve and release the brake pedal. Repeat the previous 2 steps until clean brake fluid flows or until at least 118 ml (4 oz) of fluid is accumulated.

    Tighten
    Tighten the hydraulic modulator bleeder valve to 9 N·m (80 lb in).

  7. Install the fluid reservoir cover.
  8. Raise and the support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

    9. Important: Flush the wheel brakes in the following sequence:

    1. Right rear
    2. Left rear
    3. Right front
    4. Left front

  9. Attach the bleeder hose to the bleeder valve at each wheel.

    10. Place the other end of the hose into a container in order to collect the draining brake fluid. Do not submerge the hose end into the fluid.

  10. Open the bleeder valve.
  11. Slowly depress the brake pedal.
  12. Close the valve and slowly release the brake pedal.
  13. Repeat the previous three steps until clean brake fluid begins to flow or at least 235 ml (8 oz) of fluid is accumulated.
  14. Lower the vehicle.
  15. Remove the J 35589
  16. Replace the following rubber components:
    17. • The brake hose assemblies
    • The master cylinder rubber parts
    • The brake caliper and wheel cylinder boots and seals
    • The hydraulic modulator
    • The ABS solenoids
  17. Repeat the entire manual flushing procedure one more time.
  18. Inspect the fluid level in the reservoir. Fill the reservoir to the correct level, if necessary.
  19. Install the fluid reservoir cap.
  20. Bleed the entire brake hydraulic system. Refer to Hydraulic Brake System Bleeding