Hello all, I spent the long weekend rebuilding the brakes on my '65 PV544. The only big problem I had was the master cylinder. I bought a rebuild kit for it. It looked fine inside. We checked it againest the illustration in the green Volvo manual. It was put together correct. The rebuild kit did not include a new spring which I thought was odd. Sometimes the piston/spring does not return when the pedal does. If you tap it with a hammer it will release. It seems to do it only when bleeding the brakes, when the system is open. I did adjust the pushrod. Did we miss something? Is the spring bad? Thanks!