See Figure 1
As mentioned before, the hydraulic brake system on your vehicle is diagonally split; the left front and right rear are part of one system and the right front and left rear part of the other. Both systems are routed through a pressure differential switch (located under the master cylinder) which is designed to warn the driver should a failure occur. If hydraulic pressure is lost in one side of the split system the switch will activate a warning light on the instrument panel, indicating that the brake system should be checked and repaired, if necessary. After repairs to the system have been made, the switch will automatically center itself and the light will go out.
- Raise the front or rear of the vehicle and safely support with jackstands.
- Open a caliper or wheel cylinder bleeder valve while a helper holds pressure on the brake pedal.
- As fluid is lost through the bleeder, the dash lamp should light.
- If the lamp fails to light, check for a burned out bulb, disconnected socket, or a broken or disengaged wire at the switch.
- Replace the warning switch if the rest of the circuit members check out.
- Fill the master cylinder and bleed the brakes after repairs have been completed.