Brake valves regulate hydraulic pressure within a vehicle’s braking system. Typically found in brake lines between the master cylinder and wheel cylinders/calipers, they control flow to individual wheels or brake circuits. Common types include proportioning valves, shuttle valves, and distribution valves, each designed for specific pressure modulation needs. Internal spool or diaphragm designs react to system pressure or wheel speed, adjusting flow to maintain stability and prevent wheel lockup. Materials are commonly steel or brass, designed for compatibility with brake fluid and high-pressure operation. Precise calibration is critical for optimal braking performance and safety.