I replaced the master cyl about 2 months ago and I still have to pump the brakes once to get the pedal up. The system is completely blead out. It is acting the same way as it was before the change. I'm thinking it is the booster, but I'm not sure. Any help?

------------------
86 Trans Am
red/silver t-top
305 TPI

 

CG,

The next time I fly through Eau Claire toward Hayward, I'll have to keep my eyes open...

Anyway, a weak/failing booster would not require you to pump the brakes to build pressure, it would only provide less assist. One stroke of the pedal would still have the same effect, but the pedal resistance would be higher.

Since you have an '86, you have the rear discs with the actuator screws for the park brake mechanism. This assembly is prone to sticking and allowing a lot of extra pad clearance. If all other normal disc brake ideas have been exhausted (warped rotors, sticky calipers, worn caliper brackets, air, bulging hoses, etc.) you might want to inspect these adjusters closely. Clean, lube with brake fluid, and readjust the lever positions as necesary. They are a PITA, but this has happened to me often with the same calipers on my daily driver Fiero.

These mechanisms were the subject of a recall, but GM (in their infinite wisdom) decided that only manual transmission cars were eligible for the recall. Apparently, automatic transmission vehicles don't need to have the parking brake applied, despite that the owners' manual states clearly that it should ALWAYS be used. My Fiero passed inspection, and my '86 TA has an automatic, so I was S.O.L.

------------------
Later,
Vader
------------------
"Make Me Bad"
Adobe Acrobat Reader 4.0

 

VADER

Next time you're coming through Eau Claire please let me know and I'll meet ya somewhere. It would be pretty cool to meet the master!