Brake System Bleeding
Brake System Bleeding
Pressure Bleeding
WARNING: Do not use any fluid other than clean brake fluid meeting manufacturer's specification. Additionally, do not use brake fluid that has been previously drained. Following these instructions will help prevent system contamination, brake component damage and the risk of serious personal injury.
WARNING: Carefully read cautionary information on product label. For EMERGENCY MEDICAL INFORMATION seek medical advice. For additional information, consult the product Material Safety Data Sheet (MSDS) if available. Failure to follow these instructions may result in serious personal injury.
NOTICE: Do not allow the brake master cylinder reservoir to run dry during the bleeding operation. Keep the brake master cylinder reservoir filled with clean, specified brake fluid. Never reuse the brake fluid that has been drained from the hydraulic system. Damage to the brake system components may occur.
NOTICE: Do not spill brake fluid on painted or plastic surfaces or damage to the surface may occur. If brake fluid is spilled onto a painted or plastic surface, immediately wash the surface with water.
NOTE: Pressure bleeding the brake system at 207-345 kPa (30-50 psi) is preferred to manual bleeding.
NOTE: When any part of the hydraulic system has been disconnected for repair or installation of new components, air can get into the system and cause spongy brake pedal action. This requires bleeding of the hydraulic system after it has been correctly connected.
NOTE: If the Hydraulic Control Unit (HCU) or any component upstream of the HCU are installed new, carry out the brake system bleed procedure first without the scan tool, followed by the brake system bleed procedure using the scan tool.
NOTE: Pressure bleed the brake system at 207-345 kPa (30-50 psi).
1. Clean all dirt from and remove the brake master cylinder filler cap and fill the brake master cylinder reservoir with clean, specified brake fluid.
2. NOTE: Master cylinder pressure bleeder adapter tools are available from various manufacturers of pressure bleeding equipment. Follow the instructions of the manufacturer when installing the adapter.
Install the bleeder adapter to the brake master cylinder reservoir and attach the bleeder tank hose to the fitting on the adapter.
- Refill the brake master cylinder reservoir with clean, specified brake fluid as necessary.
3. Place a box-end wrench on the master cylinder bleeder screw. Attach a rubber drain hose to the bleeder screw and submerge the free end of the hose in a container partially filled with clean, specified brake fluid.
4. Open the valve on the bleeder tank.
5. Loosen the bleeder screw and leave open until clear, bubble-free brake fluid flows into the container.
- Tighten the master cylinder bleeder screw to specification. Refer to Specifications.
- Remove the rubber hose.
6. NOTE: Bleed from the longest to the shortest brake line. Make sure the bleeder tank contains enough clean, specified brake fluid to complete the bleeding operation.
Remove the brake caliper bleeder screw cap and place a box-end wrench on the bleeder screw. Attach a rubber drain hose to the brake caliper bleeder screw, and submerge the free end of the hose in a container partially filled with clean, specified brake fluid.
7. NOTE: Have an assistant press the brake pedal approximately 25 mm (0.98 in) once every 2 seconds while pressure bleeding. This will enhance the pressure bleeding procedure.
Loosen the bleeder screw and leave open until clear, bubble-free brake fluid flows into the container. Wait 15 seconds after clear, bubble-free fluid flows through the rubber hose.
8. Tighten the brake caliper bleeder screw to specification. Refer to Specifications.
- Remove the rubber hose and install the bleeder screw cap.
9. Continue bleeding the brake system repeating Steps 7 through 9 at all wheel ends.
10. Close the bleeder tank valve. Remove the tank hose from the adapter and remove the adapter.
11. Inspect the brake fluid level in the master cylinder reservoir.
- Fill the brake master cylinder reservoir with clean, specified brake fluid if necessary.
12. Install the reservoir cap.
13. NOTE: If the brake pedal remains spongy, air may be trapped in the HCU.
If the brake pedal remains spongy after pressure bleeding, carry out the ABS Hydraulic Control Unit (HCU) Bleeding procedure with the scan tool.
Manual Bleeding
WARNING: Do not use any fluid other than clean brake fluid meeting manufacturer's specification. Additionally, do not use brake fluid that has been previously drained. Following these instructions will help prevent system contamination, brake component damage and the risk of serious personal injury.
WARNING: Carefully read cautionary information on product label. For EMERGENCY MEDICAL INFORMATION seek medical advice. For additional information, consult the product Material Safety Data Sheet (MSDS) if available. Failure to follow these instructions may result in serious personal injury.
NOTICE: Do not allow the brake master cylinder reservoir to run dry during the bleeding operation. Keep the brake master cylinder reservoir filled with clean, specified brake fluid. Never reuse the brake fluid that has been drained from the hydraulic system. Damage to the brake system components may occur.
NOTICE: Do not spill brake fluid on painted or plastic surfaces or damage to the surface may occur. If brake fluid is spilled onto a painted or plastic surface, immediately wash the surface with water.
NOTE: When any part of the hydraulic system has been disconnected for repair or installation of new components, air can get into the system and cause spongy brake pedal action. This requires bleeding of the hydraulic system, including the HCU after it has been correctly connected.
NOTE: If the HCU or any component upstream of the HCU are installed new, carry out the brake system bleed procedure first without the scan tool, followed by the brake system bleed procedure using the scan tool.
1. Clean all dirt from and remove the brake master cylinder filler cap and fill the brake master cylinder reservoir with clean, specified brake fluid.
2. Place a box-end wrench on the master cylinder bleeder screw. Attach a rubber drain hose to the bleeder screw and submerge the free end of the hose in a container partially filled with clean, specified brake fluid.
3. Loosen the bleeder screw and leave open until clear, bubble-free brake fluid flows into the container.
- Tighten the master cylinder bleeder screw to specification. Refer to Specifications.
- Remove the rubber hose.
4. NOTE: Bleed the brake system from the longest to the shortest brake line.
Remove the brake caliper bleeder screw cap and place a box end wrench on the bleeder screw. Attach a rubber drain hose to the bleeder screw and submerge the free end of the hose in a container partially filled with clean, specified brake fluid.
5. Have an assistant pump the brake pedal and then hold firm pressure on the brake pedal.
6. Loosen the bleeder screw until a stream of brake fluid comes out. While the assistant maintains pressure on the brake pedal, tighten the bleeder screw.
- Repeat until clear, bubble-free fluid comes out.
- Refill the brake master cylinder reservoir as necessary.
7. Tighten the brake caliper bleeder screw to specification. Refer to Specifications.
- Remove the rubber hose and install the bleeder screw cap.
8. Repeat Steps 5 through 8 for the remaining brake calipers.
ABS Hydraulic Control Unit (HCU) Bleeding
NOTE: The Hydraulic Control Unit (HCU) bleeding procedure must be carried out if the HCU or any components upstream of the HCU are installed new.
NOTE: Pressure bleeding the brake system is preferred to manual bleeding.
1. Follow the pressure bleeding on manual bleeding procedure steps to bleed the system.
2. Connect the scan tool and follow the ABS Service Bleed instructions.
3. Repeat the pressure bleeding or manual bleeding procedure steps to bleed the system.