Failure Warning Switch

Fig. 8 Failure Warning Switch. Rear System Failure:

DESCRIPTION
If the rear brake system fails, the front system pressure forces the switch piston to the right, Fig. 8. The switch pin is then forced up into the switch, completing the electrical circuit and activates the dash warning lamp.

OPERATION
When repairs are made and pressure returns to the system, the piston moves to the left, resetting the switch. The detent on the piston requires approximately 100 to 450 psi to permit full reset of the piston. In event of front brake system failure, the piston moves to the left and the same sequence of events is followed as for rear system failure except the piston resets to the right.