Description & Operation

All models are equipped with front disc brakes and rear drum brakes. Hydraulic system is split front and rear. Parking brake lever assembly sets rear brakes using a cable and mechanical linkage system. System uses a Load Sensitive Proportioning Valve (LSPV). LSPV consists of a lever and load sensing spring. Spring senses variations in vehicle ride height, proportioned to load weight. A plunger and valve inside the LSPV perform the hydraulic pressure modulation. A chamber with a fail safe piston, monitors front brake pressure. If front system loses pressure, the piston releases the plunger/valve assembly and cancels pressure modulation. This allows full hydraulic pressure to the rear brakes. LSPV is bolted to the frame, with lever connected to the upper suspension arm. As the load in the vehicle increases, the distance between the axle housing and frame decrease. This action causes the lever to move and actuate the plunger such that the rear brake pressure is increased in proportion to weight increase.