Genuine Pontiac Fiero Brake Proportioning Valve

Pontiac Fiero Brake Proportioning Valve Parts Questions & Experts Answers

• VALVE ASM
  10036563
  Q: Is the combination valve repairable, and how should it be replaced and tested on Pontiac Fiero?

  A: The combination valve is not repairable and must be replaced as a complete assembly. To test the electrical circuit, first remove the electrical wire connector from the pressure differential switch by squeezing the sides of the elliptically shaped plastic locking ring and pulling up, which will move the locking tabs away from the switch; a pliers can assist in this process. Next, use a jumper wire to connect the switch wire to a good ground, then turn the ignition key to On, which should light the warning lamp on the instrument panel. If the lamp does not light, the bulb may be burned out or the electrical circuit defective, necessitating replacement or repair. When the warning lamp lights, turn the ignition switch Off, disconnect the jumper, and reconnect the wire to the switch terminal. For testing the warning light switch, attach a hose to one rear brake bleeder valve and immerse the other end in a container filled with clean brake fluid, ensuring that the master cylinder reservoirs are full. Turn the ignition switch to On, open the bleeder valve while an assistant applies moderate pressure to the brake pedal, which should light the warning lamp; close the bleeder valve before the assistant releases the pedal, then reapply moderate-to-heavy pressure to the brake pedal, causing the lamp to go out. Repeat this test with a hose attached to one front brake bleeder valve and turn the ignition switch off. If the warning lamp does not light during these tests but does light when a jumper is connected to ground, the warning light switch portion of the combination valve is defective and the entire combination valve must be replaced. For replacement, disconnect the hydraulic lines at the combination valve and plug them to prevent fluid loss and contamination, then disconnect the warning switch wiring harness from the valve switch terminal. Remove the combination valve mounting bolt and detach the valve, then install the new combination valve and securely tighten the mounting bolt. Install the hydraulic line fittings and tighten them securely, plug in the warning switch wiring harness to the valve switch terminal, and bleed the entire brake system.