Brake Fluid Pressure Sensor/Switch: Service and Repair

PRESSURE DIFFERENTIAL WARNING VALVE, RECONDITIONING

(Installed only on cars without ABS and on models to 1987 incl.)





Q1. Lock brake pedal in depressed position
Use pedal clamp.
Collect any brake fluid which escapes.
Q2. Inspect and clean (if necessary) warning valve plugs and switch





Q3. Remove/disconnect:
^ lead and switch
^ end plugs
^ piston, spring and O-rings
Clean components.
Q4. Replace O-rings
Lubricate rings with brake fluid

Assembly





Q5. Reinstall:
^ rear plug
^ piston assembly. Use socket of dimensions shown to facilitate installation of piston.
^ front plug
Q6. Remove pedal clamp
Bleed braking system

Note: Operate pedal for 30 seconds (hard braking) when system has been bled. Inspect switch unit for signs of fluid leakage.

If leakage is present, replace complete valve. If no leakage is present, reinstall switch and reconnect lead.