A-Team performance chrome GM Chevy disc drum brake proportioning valve pv2 new factory replacement pv2c-2 This is a universal combination valve, disc/drum brakes, brass, an exact copy of the original ac delco style proportioning-combination valve in brass. Carry individual proportioning valves for your customized application. Works on, and mopar. These combination-proportioning valves are based on the popular AC Delco 172-1353 (disc-drum) and 172-1361(disc-disc) valves. When upgrading your vehicle from drum to disc, these small items are a must. These components ensure proper fluid transfer and contain a residual pressure valve for a proper braking feel. These valves contain a low-pressure shut-off valve and warning light switch to ensure driver and vehicle safety should your brake system lose hydraulic line pressure. Aftermarket imported master cylinders with built-in adjustable proportioning valves do not feature this and could put you and your vehicle at risk.