Brass Proportioning Valve Disc/Drum Disc Front Drum Rear Brake 172-1353 Fit For Chevy Classic Car & Truck Enhances braking safety with our advanced proportional control technology brake load sensing valves, featuring high precise sensors for intelligent hydraulic pressure adjustment to boosts response and stability. This load sensing brake valves boasts real time automatic adjustment based on vehicle weight, and is crafted from corrosions resistant materials for durability in harsh conditions. Produced from heavy-duty plastic, this component is highly resistant to rust and damage, ensuring an extended operational life. The cylinder oil separator breather valve stops fluid from flowing back into the master cylinder, thus keeping pipeline pressure low., Manufacturer: HAYSXVR