Screw Type Brake Proportioning Valve

The AP Racing CP3550-14 screw-type proportioning valve provides precise control over brake pressure for competition vehicles. Its infinite adjustment capability allows drivers to tailor braking bias to specific track or road conditions. When the cap is fully screwed in, there is no reduction in output pressure, maintaining full rear brake effectiveness. Conversely, when the cap is fully unscrewed, the output pressure is reduced to approximately one-third of the input pressure, allowing for more front brake bias when needed. This valve features a nominal ratio of 0.325 and is constructed for reliable performance under demanding conditions, weighing approximately 180g. It is compatible with DOT 3, DOT 4, and DOT 5.1 brake fluids, with AP Racing recommending their own 600 brake fluid for optimal results. Installation involves biasing the brake system towards the rear initially, with the valve piped into the rear line. Adjustments are then made by turning the screw cap outwards to progressively reduce rear line pressure, thereby increasing front brake bias as grip levels change. AP Racing strongly advises against disassembling or modifying these valves due to their internal adjustments. This component is strictly intended for competition use only.