Brake Hose/Line: Description and Operation

PROPORTIONING VALVE






A proportioning valve has been adopted to prevent early locking of the rear wheels, in order to provide improved stability during braking.

BRAKE FLUID PRESSURE CONTROL





1. BELOW SET FLUID PRESSURE POINT
When the input fluid pressure from the master cylinder is below the set pressure, the valve is held in its left-most position by the spring. thus, input fluid flows through the passage between the valve and seal and is supplied to the wheel cylinders with no reduction in pressure.





2. FROM SET FLUID PRESSURE POINT UPWARD
When the input fluid pressure from the master cylinder reaches and exceeds the set pressure, the output fluid pressure applied to the rear brakes acts as a reaction pressure and pushes the valve rightward until it pressure against the seal, thus closing the passage. At this time, the output fluid pressure diminishes relative to the input fluid pressure, initiating a pressure reduction effect.
If the input fluid pressure from the master cylinder increases further, the valve moves leftward, allowing fluid to pass between the valve and seal such that the pressure supplied to the rear brakes increases. By repeatedly closing and opening the passage in this way, the valve maintains the optimum balance between the input and output pressures.