Master Cylinder Priming - In-Vehicle or Bench
Master Cylinder Priming - In-Vehicle or BenchSpecial Tool(s):
Material:
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: When any part of the hydraulic system has been disconnected for repair or replacement, air can enter the system and cause spongy brake pedal action. This requires bleeding of the hydraulic system after it has been properly connected. The hydraulic system can be bled manually or with pressure bleeding equipment.
NOTE: When the brake master cylinder has been replaced or the system has been emptied, or partially emptied, it should be primed to prevent air from entering the system.
1. For in-vehicle priming, disconnect the brake lines.
2. For bench priming, mount the brake master cylinder in a vise.
3. install short brake tubes with the ends submerged in the brake master cylinder reservoir, and fill the brake master cylinder reservoir with specified brake fluid.
4. Have an assistant pump the brake pedal, or slowly press the primary piston until clear fluid flows from both brake tubes, without air bubbles.
5. If the brake master cylinder is being primed at the bench, install it in the vehicle.
6. Remove the short brake tubes, and install the brake outlet tubes.
7. Bleed each brake tube at the brake master cylinder as follows:
1 Have an assistant pump the brake pedal, and then hold firm pressure on the brake pedal.
2 Loosen the rearmost brake tube fittings until a stream of brake fluid comes out. While the assistant maintains pressure on the brake pedal, tighten the brake tube fitting.
^ Tighten to 25 Nm (18 ft. lbs.).
3 Repeat this operation until clear, bubble-free fluid comes out.
4 Refill the brake master cylinder reservoir as necessary. Repeat the bleeding operation at the front brake tube.