Check the listing for details. AP SCREW TYPE BRAKE BIAS VALVE – CP35510-14. Condition: New. Listed at 246.94 USD. AP Racing brake proportioning valves are designed for use in competition vehicles where it is desired to reduce the brake line pressure to compensate for varying road / track conditions. Allows brake balancing from front to rear to compensate for changing road / track surfaces Includes an indicator plate which creates a positive affirmation of each full turn, ideal for adjusting on the fly Fitting in line the valve offers no restriction when screwed in fully, but reduces pressure by approximately 33 percent when fully opened. The screw operation of the valve allows for precise adjustment of the pressure anywhere between fully closed and open to give the best possible braking balance. The lightweight and compact body includes 2 holes for mounting to a panel or bulkhead and features inlet an.