Single Heavy Duty Brake Proportioning Valve Bleeder Tool ✔️ Blue steel handle fits GM combos disc drum props plus PV2 units This blue anodized bleeder wrench locks the low pressure exhaust valve inside your proportioning valve so you can safely purge trapped air without messing up wheel pressure balance. Mechanics rely on this handy garage tool when flushing brake fluid on disc disc or disc drum setups to restore a firm pedal feel. ✅ Works with all common GM non adjust combination valves and PV series models ✅ Keeps the exhaust valve centered to stop piston drift during fluid flushes ✅ Compatible with CPP proportional valve setups to prevent tripped warning lights ✅ Simple squeeze handle design speeds up bench bleeder hook ups 💡 Why does brake fluid need special bleeding procedures for proportioning valves? Locked bleed ports isolate the master cylinder to maintain perfect split ratios during service. - Air pockets in the ABS module trap moisture and ruin stopping power fast. - Proper flush removes compressible gas that makes pedals mushy under heavy loads. - Locked exhaust ports keep pressure balanced while you pump old fluid out. ✝️