OEM 2004 Toyota Prius Brake Master Cylinder

2004 Toyota Prius Parts Questions & Experts Answers

• Q: How to replace the brake master cylinder sub-assembly on 2004 Toyota Prius?

  A: The brake master cylinder sub-assembly replacement begins with removal of front wiper arms from both sides and the hood to cowl top seal before you take out the two cowl top ventilator louvers from left and right sides. Then remove the windshield wiper motor with its link assembly. The brake control (ECB) requires a shutdown with removal of motor relays No.1 and No.2 because the brake actuator hose air creates bleeding complications. The outer front portion of the cowl top panel sub-assembly needs to be removed by disconnecting 2 bolts, 3 clamps, and 7 bolts. The service technician should begin by draining brake fluid from the w/converter inverter assembly before extracting the instrument panel register assembly No.1 and instrument panel finish panel sub-assembly lower. To remove the brake master cylinder sub-assembly the technician should first remove the brake return spring and push rod pin along with the clip and then deal with four retaining clips and two reservoir tube hoses before separating the actuator bracket bolt. Special Service Tool: 09023-00100 should be used to disconnect front brake tube No.1 while following steps to separate front brake tube No.2 from the clamp with brake master cylinder sub-assembly. The procedure to detach the brake master cylinder sub-assembly consists of removing first two nuts and a gasket and the brake master cylinder sub-assembly. The same tool serves for separating the brake tube and 2-way from the brake master cylinder sub-assembly. You must first remove the screw to separate the brake master cylinder union No.1 and 2 grommets and after that loosen the clevis lock nut to extract the push rod clevis. The push rod clevis installation process begins with attaching it to the brake master cylinder sub-assembly and using the lock nut to secure it before adding lithium soap base glycol grease to new grommets and screwing them into place at 1.8 Nm (18 kgf-cm, 16 inch lbs). Use Special Service Tool: 09023-00100 to install the brake tube and 2 way, torqued to 15 Nm (155 kgf-cm, 11 ft. lbs.). Additional Steps involve installing the brake master cylinder sub-assembly with the gasket using two nuts to a torque value of 13 Nm (127 kgf-cm, 9 ft. lbs.). Use the same tool to fasten front brake tubes No.1 and No.2 before installing the actuator bracket bolt to 5.0 Nm (51 kgf-cm, 44 inch lbs.). Finally, reattach the brake tube reservoir tubes using clips before you place the push rod clevis assembly which features the master cylinder push rod pin into the brake pedal position and add the clip with return spring. The w/converter inverter assembly and cowl top panel sub-assembly outer front should be reinstalled with 7 bolts torqued to 6.4 Nm (65 kgf-cm, 57 inch lbs.) and 3 clamps and engine room R/B No.2 should be installed with 2 bolts torqued to 8.4 Nm (86 kgf-cm, 74 inch lbs.). The final installation step includes front wiper arms (both left and right) and the windshield wiper motor and link assembly then proceed with filling the brake fluid reservoir and cylinder bleeding with Special Service Tool: 09023-00100 before checking for leakage and fluid level and brake pedal adjustments followed by lower instrument panel finish panel sub-assembly reinstallation with Instrument panel register assembly No.1 and clearing all detected technical problems.