Brake System Bleeding
Brake System BleedingSpecial Tool(s):
Material:
Pressure Bleeding
WARNING: Use of any brake fluid other than approved DOT 3 will cause permanent damage to brake components and will render the brakes inoperative. Failure to follow these instructions may result in personal injury.
WARNING: Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with eyes. Wash hands thoroughly after handling. If brake fluid contacts eyes, flush eyes with running water for 15 minutes. Get medical attention if irritation persists. If taken internally, drink water and induce vomiting. Get medical attention immediately. Failure to follow these instructions may result in personal injury.
CAUTION: Do not allow the brake master cylinder reservoir to run dry during the bleeding operation. Keep the brake master cylinder reservoir filled with the specified brake fluid. Never reuse the brake fluid that has been drained from the hydraulic system.
CAUTION: Brake fluid is harmful to painted and plastic surfaces. If brake fluid is spilled onto a painted or plastic surface, immediately wash it 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 diagnostic tool, followed by the brake system bleed procedure using the diagnostic 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 DOT 3 motor vehicle 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.
NOTE: For ABS only vehicles, open the master cylinder bleed screw until clear, bubble-free fluid flows from the tube into the cup.
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, as necessary.
3. NOTE: Bleed from the longest to the shortest brake line. Make sure the bleeder tank contains enough DOT 3 motor vehicle brake fluid to complete the bleeding operation.
Place a box end wrench on the bleeder screw. Attach a rubber drain tube to the bleeder screw, and submerge the free end of the tube in a container partially filled with DOT 3 motor vehicle brake fluid.
4. Open the valve on the bleeder tank.
5. NOTE: Have an assistant press the brake pedal approximately 25 mm (0.98 inch) once every 2 seconds while pressure bleeding. This will enhance the pressure bleeding procedure.
Loosen the bleeder screw. Leave open until clear, bubble-free brake fluid flows. Wait 15 seconds after clear, bubble-free fluid flows through the rubber hose. Then, tighten the bleeder screw and remove the rubber hose.
^ Tighten to 21 Nm (15 ft. lbs.).
6. Continue bleeding the brake system repeating Step 5 at all wheel ends.
7. Close the bleeder tank valve. Remove the tank hose from the adapter, and remove the adapter.
8. Inspect the brake fluid level in the master cylinder reservoir.
^ Fill the brake master cylinder reservoir with DOT 3 motor vehicle brake fluid, if necessary.
9. Install the reservoir cap.
10. NOTE: If the brake pedal remains spongy, air may be trapped in the HCU.
If the brake pedal remains spongy after pressure bleeding, perform the Anti-Lock Brake System (ABS) Hydraulic Control Unit Bleeding procedure with the diagnostic tool.
Manual Bleeding
WARNING: Use of any brake fluid other than approved DOT 3 will cause permanent damage to brake components and will render the brakes inoperative. Failure to follow these instructions may result in personal injury.
WARNING: Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with eyes. Wash hands thoroughly after handling. If brake fluid contacts eyes, flush eyes with running water for 15 minutes. Get medical attention if irritation persists. If taken internally, drink water and induce vomiting. Get medical attention immediately. Failure to follow these instructions may result in personal injury.
CAUTION: Do not allow the brake master cylinder reservoir to run dry during the bleeding operation. Keep the brake master cylinder reservoir filled with the specified brake fluid. Never reuse the brake fluid that has been drained from the hydraulic system.
CAUTION: Brake fluid is harmful to painted and plastic surfaces. If brake fluid is spilled onto a painted or plastic surface, immediately wash it 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, including the hydraulic control unit (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 diagnostic tool, followed by the brake system bleed procedure using the diagnostic tool.
1. Clean all dirt from and remove the brake master cylinder filler cap and fill the brake master cylinder reservoir with DOT 3 motor vehicle brake fluid.
2. NOTE: For ABS only vehicles, open the master cylinder bleed screw until clear, bubble-free fluid flows from the tube into the cup.
NOTE: Bleed the brake system from the longest to the shortest brake line.
Place a box end wrench on the bleeder screw. Attach a rubber drain tube to the bleeder screw and submerge the free end of the tube in a container partially filled with DOT 3 motor vehicle brake fluid.
3. Have an assistant hold firm pressure on the brake pedal.
4. 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 and release the pedal pressure.
^ Release the brake pedal.
^ Repeat 3 times or until clear, bubble-free fluid comes out.
^ Refill the brake master cylinder reservoir as necessary.
5. Tighten the bleeder screw.
^ Tighten to 21 Nm (15 ft. lbs.).
6. Repeat Steps 2 through 5 for the remaining bleeder screws in the system.