Master Cylinder & Brake Lines

WARNING: DO NOT allow reservoir to run dry during brake bleeding procedure. Use only clean brake fluid. Ensure no dirt or other foreign matter contaminates brake fluid. DO NOT mix different brands of brake fluid, as they may not be compatible.

CAUTION: DO NOT spill brake fluid on vehicle, as it may damage paint. If brake fluid contacts paint, immediately wash with water.

NOTE: If any of these conditions exist, bleed the brake system.

Work has been done on the brake system.
It is suspected the brake system has air in it.
Master cylinder is rebuilt or disassembled.
Reservoir is empty.

NOTE: Manufacturer recommends fluid type SAE J1703 or FMVSS No. 116 DOT3.

Ensure brake fluid reservoir remains full of brake fluid during bleeding procedure. Check the fluid level in the reservoir after bleeding each wheel. Add fluid, if necessary.
Bleed master cylinder:
1. Use a flare nut tool to disconnect the brakeline union nuts from the master cylinder.
2. Slowly depress the brake pedal and hold it in the depressed position.
3. Block off the brake master cylinder outlet plugs with your fingers. Slowly release the brake pedal.
4. Repeat steps "B" and "C", 3 or 4 times until air clears out of master cylinder.
5. Reconnect the brake lines. Tighten the union nuts to specification. See TORQUE SPECIFICATIONS .

WARNING: Bleed the rear brakes first. If front brakes are bled first, the rear brakes air cannot be bled.

Bleed brake lines:
1. Connect an appropriate tube to the bleeder screw at the caliper or wheel cylinder, and insert the other end of the tube into an appropriate container to catch the fluid. See Fig 1.
2. Depress the brake pedal several times. Hold the brake pedal in the depressed position, loosen the bleeder screw to release air.
3. When the fluid/air is released, tighten the bleeder screw. Release the brake pedal.
4. Repeat steps "B" and "C" until all the air in the brake fluid system is bled out. Confirm air is bled by ensuring there are no air bubbles visible in the fluid in the tube. Refill brake fluid reservoir as necessary. Tighten the bleeder screw to specification. See TORQUE SPECIFICATIONS .
5. Ensure fluid leakage is not present and fill the reservoir.
6. Repeat the above procedure for the brakeline of each wheel.

NOTE: When repairing the master cylinder or precharge pump, bleed the precharge pump of the air.

Bleed precharge pump:
1. Install an appropriate pump to the brake fluid reservoir. See Fig 2.
2. Using the installed pump, apply 14.2 psi (98.1 Kpa) of pressure to the brake fluid reservoir.
3. Disconnect the precharge pump electrical connector. See Fig 3.
4. Connect connector lead 2 to the battery positive and connector lead 1 to the battery negative, and activate the precharge pump about 20 seconds. See Fig 5.
5. Remove the installed pump from the reservoir.
6. Connect the vinyl tube to the right side front brake caliper. Submerge the other end of the tube in brake fluid, and loosen the bleeder screw. See Fig 1.
7. Activate the precharge pump again until there are no more air bubbles in the fluid. Tighten bleeder screw to specification. See TORQUE SPECIFICATIONS .
8. Connect the precharge pump connector. See Fig 3.

NOTE: Manufacturer recommends fluid type SAE J30 or FMVSS No. 116 DOT3.

Check fluid level in brake fluid reservoir, and add as necessary.

Fig 1: Bleeding Wheel Cylinders

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Bleeding Precharge Pump

Fig 3: Identifying Master Cylinder Components Vehicle Without Vehicle Skid Control

Fig 4: Identifying Master Cylinder Components Vehicle With Vehicle Skid Control

Fig 5: Identifying Precharge Pump Terminals