Brake Failure Warning Light Switch: Operation

Switch consists of a single piston activated on one end by hydraulic pressure from front brake system and on other end by pressure from rear brake system. If pressure is equal on both ends, piston will not move. If pressure drops on one end, higher pressure of opposite end will force piston to low pressure side. Piston movement will actuate switch causing brake warning indicator to light. Switch can be tested for proper operation by loosening a bleeder screw while pressure is being applied to brake pedal and observing light.

Test both front and rear systems, then reset switch if necessary.