IanS

iTrader: (4)

I am stuck. I have worked on fixing my brakes and clutch all day today. I finally got the clutch to bleed correctly after priming it. This leads me to the brake master cylinder and the problems I am now dealing with in regards to it.

First off, I couldnt get the brake master cylinder primed so I tore it apart and compared the new parts to the old. It seemed that the plunger that runs the front brakes was shorter than the original. No big deal, just turn the screw on the end to adjust it. This made it so the fluid would be pulled in from the reservoir and then pumped to its outlet like it should. This was all fine and dandy, except with the new length came another problem. The plunger would be flush with the very end of the master cyl. and I would not be able to install the lock ring that holds it in. I installed the master cylinder to the booster without the lock ring simply to test wether or not it worked like this. After installation, I could not get the master to prime. Thinking of what could have been the problem, I loosened the master from the booster a bit. I was able to prime the brake master cylinder correctly and it seemed to be building pressure correctly, though it still had a squishy feel (havent bled brakes yet). With it installed all the way, I basically have no pedal pressure at all. I can bleed the rear, but not the front.

So now, heres my problem. Is it ok to install a couple washers behind the master cylinder so I get full travel of the plunger? Will that somehow effect the booster? If the booster and the master are not mated tight, will there be some sort of vaccuum leak? I also noticed that their seems to be a leak when I press the brake pedal coming from the booster, in between it and the master cylinder. Is there some sort of gasket that will fix this? Please help me as I am kinda lost on this one. This is my first time rebuilding a master cylinder (other than my clutch one that went ok).

I know that no one likes to read such a long post but I wanted to explain the problem as good as I could. Thanks

-Ian

IanS

iTrader: (4)

bump

nimrodTT

It's been years since I've rebuilt a master cylinder (I just buy rebuilt ones since they are only a few dollars more), but I don't recall anything about the secondary piston being adjustable. Where did you get the rebuild kit from?

Are you saying you can't bench-prime with it in the original configuration or you can't get it to prime while installed? You need to bench prime, then install, then bleed.

IanS

iTrader: (4)

I cannot bench prime it with the original configuration. After changing the (what I believe) primary piston (the one that runs the front brake lines), I can bench prime it and then after installation onto the booster it will not prime. The reason, I figured out is that the piston does not travel back far enough to draw fluid in from the reservoir. I also figured out that my booster itself is leaking. Is there a rebuild kit available? I know that VB sells remanufactured ones but I would prefer to rebuild it myself. I would like to gain a better knowledge of braking systems and how they work. Rebuilding the clutch and brake master cylinders have given me quite a bit of insight on how it all works.

Oh yeah, I bought the rebuild kit from VB. It is the Raybestos - "The best in brakes" kit. Also, as far as the booster is concerned, I have a couple spares so I will try them out and hopefully they wont leak. I may just replace the whole assembly from one of my spares.

Thanks for the questions and help.

-Ian

Rogue_Wulff

You said the booster is leaking. Is fluid leaking from it? If so, it's the master cly that is leaking, there should not be any fluid in the booster. As far as rebuilding the booster, that requires some special equipment. There is a large spring inside it, and without the proper caging equipment, it can be very danderous to attempt disassembly. Assembly is even harder.

nimrodTT

I haven't seen a VB catalog in years, but everything they used to sell was overpriced and generally total crap. There was nothing they sold that I couldn't get elsewhere for cheaper and/or better quality. Even the dealership sells many parts for less.

Reman master from the local Oreilly's is $45, a brand new one with reservoir from Autozone is $63. What's VBs price?

IanS

iTrader: (4)

I fixed the problem. I guess the entire time it was just my booster leaking. I put the one from my 85 GSL parts car in. I changed out the brake master cylinder with one that looked newer from my 85 GS parts car. It all seems to work good now, except I found out that I need new front brake rotors and also I am pretty sure I destroyed my rear drums. I guess the shoes were wore down to nothing and I didnt know this as I had limited stopping power before. I could lock up the tires but the pedal was real squishy. Either way, the hydraulics part of my brakes are working excellent now and all I need is new hardware components (rotors, pads, shoes). Has anyone had a good/bad experience from a normal aftermarket brand? I figure I will get them from O'Reilly's as I have had decent luck with their brake components in the past.

The price from VB for a new brake M/C is 100 bucks. The rebuild kit was 10, so I cheaped out but luckily it was only 10 bucks.

Rogue_Wulff

Most generally, the stuff you can get from auto parts stores is of a decent quality, even though it is just a stock replacement. I have pads and shoes on my car from O'riellys, as well as a front caliper. All seems to be good with it.

IanS

iTrader: (4)

Another update on the rear brakes. I placed a plug on the master cylinder so fluid would not go to the rear brakes. I bought a plug so this would be reversable, as I do want rear brakes sometime. The rear brakes would drag and get so hot that they would start to stick. I am now only running on front brakes and I have to say I like the pedal feel. The pedal reacts like my Dad's 62 corvair (all 4 wheels have drum brakes). The pedal goes down a little bit and then you really have to push down to get the car to stop. Very hard, but good feedback from the brake pedal.

SilverArrow

yay...don't hear "brakes like a corvair" too often

Rogue_Wulff

The reason the pedal goes down a bit, then gets real hard, is the plug you put in the rear brake portion of the M/C. Not a good idea, in my opinion. I understand that the rear brakes are totally worn out, but that is just too risky to drive like that. A real good way to crash the car, due to not being able to stop. Ask me how I know about sucking "pucker donuts" in the seat, from having rear brakes that don't work. Believe me, I fixed them the next day, and used the wife's car to go after parts.
For the love of the first gen, park it till you can repair the brakes to a fully functional state. The life you save could be your own.

IanS

iTrader: (4)

They still function correctly, the brake pedal is simply harder to press down. With the corvair comment, yeah I know not the best car to be comparing but its the only thing I know of that I can compare it to. Anyways, I can still lock up the tires relatively easily so I have full stopping power up front. I rarely drive the car anyways and the shoes are going to be here on thursday. This was just a simple inexpensive way of making less wear and still being able to drive the car that has been down for 2 weeks for having no clutch and shitty brakes.

jays83gsl

You could say it brakes like my 323