C2 power brakes

[Paul Burrelli]

Just rebuilt the power brakes on my 65. Everything is new except for the power booster and the master cylinder. The MC was sleeved and rebuilt. All I did to the booster was take it apart and have the housing plated. It worked fine when I took it apart so I didn't give it a second thought. I didn't do anything to the power piston except wipe it off and put the thing back together.

Spent a lot of time trying to bleed the brakes but finally with the help of a homemade pressure bleeder was sucessful. Read most of the posts about brakes in the archives but I'm still not sure what to do.

My problem is when I step on the brakes with the engine running the pedal goes to the floor and locks the brakes. I can pull it back by hand but it's not easy. I hate to pull the booster off again if I don't have to but not sure what's happening. I don't really understand how this vacuum thing works. Is the trouble in the MC, booster, or could it be just an adjustment? I really need some help here. I'll appreciate any help you guys may have. Thanks, Paul

[cdonr]

Re: C2 power brakes

I replaced my master cylinder an had the same kind of problem. You could check the piston in the master make sure it returns, had a bad one once and it seems I couldnt bleed it out either. It was a fresh rebuilt also. There is also some adjustment on the rod ( not sure what you call it) between the booster and the master, drives the piston, I had to play around with it to get it working good luck. Chris

[Werner R.]

Re: C2 power brakes

i had a somewhat similar experience that i posted on the corvette forum. what i found was that the "ears" on the springclip that hold the piston assembly into the master cylindr were grabbing the shaft of the rod coming out of the power booster. in other words, i step on the brakes but they will not release except with a lot of efort by hand. my temporary cure was to snap off the ears on the circle clip. this will make it harder but not impossibe to remove the piston assembly from the MC if i have to in the future. i have had no roblems since i snappd off the ears. at lest worth checking out.

[Craig S.]

Re: C2 power brakes

Werner - it sounds as if the clip is improper if it is was binding on the transfer shaft. While I realize your solution is working, I wish you all the luck getting the clip out in the future, it sounds like a challenge to me!...Craig

[Werner R.]

Re: C2 power brakes

craig
i agree, the clip might be improper. i know what you mean about removing the clip, but i did it once in the basement just to make sure it is possible. it was putsy, but i was able to remove it using two very small bladed screwdrivers [of course, the trick is not to slip and scratch the cylinder wall].
i'll probably replace the MC next year anyway, because someone did scratch the cylinder wall, and even though i honed it out, it has, after 5 years, finally developed a slow leak.
werner

[Craig S.]

Re: C2 power brakes

Werner - you commented it was sleeved already, I was thinking of going to apple hydraulics or white post restorations with mine. They may be able to resleeve your unit if it is original, vs replace....Craig

[Werner R.]

Re: C2 power brakes

craig
no, no, mine has not been resleeved. it's just that someone years ago really scratched up the cylinder wall, probably trying to get out the spring clip.

actually, years ago i had the combined brake and clutch MC of my MGA resleeved by white post [i think that is the name]. they did a great job, and i think the sleeves were bronze. never worried about rust again. well worth it.

[Craig S.]

Re: C2 power brakes

Werner - my fault, it was Paul at the top of this thread that posted resleeved...sorry for my confusion...Craig

[Geoff C.]