Stiletto

Been trying to diagnose this one for a while, and I have come up empty. When I let off the brake, the pedal is returning very slowly, often taking several seconds to return. The pads are still gripping most of this time, resulting in increased brake pad wear. Clutch return is fine. Based on a few searches here, I have tried replacing the hydraulic master cylinder with a new one and re-bled the system, no help. Any other ideas?

arthropraxis

Look up around the pedal and see if the return spring is broken or missing.

Stiletto

Yea, the spring seems fine. In fact, when the car is off, I pump the brakes a few times (hear air moving each pump), afterwards the pedal returns normally. When the engine is running, slow return. Re-bleed the brake lines and slave cylinder?

arthropraxis

If the problem happens with the car running check for vacuum leaks to the brake booster.