MPD47

You may have read my question asking about brake pad quantities the other day. Well now i have my brake parts, but i think my master cylinder is shot. I can bleed the system, however it feels extremely weak while bleeding the rear wheels, and when im done bleeding the whole system, no amount of pumping will get any preasure the to pedal. Is my master cylinder shot? Or am i missing something? I have no leaks, ANYWHERE, and ive pulled the master apart and not found any scoring, rust, or anything out of place. Suggetions? I'm almost out of ideas.

Jakerx

bump

Kevin Baker

When you bled the system, did you start at the right rear, move left rear, then right front, then left front?

If the system is bled and the pedal is still soft you may have a master cylinder problem. To check, after its bled, press the pedal with a firm steady pressure, if the pedal continues to drop under steady pressure, the master cylinder may be "bypassing". Or leaking past the piston/seals.

MPD47

Yeah i bled the system the correct way, still no pedal though.

Dave951M

One tip for bleeding the brakes, don't press the pedal all the way to the floor. Sometimes there is a "ridge" inside the master cylinder that abrades the piston seals and can cause a master cylinder failure.

Sounds to me like the master is shot in your case.