Master cylinder?????

[dirtywhiteboy]

Ok so I checked vacuum line and booster. Nothing. Pedal still hard as a rock and no brakes to speak of. So.......... anyone got any ideas? I'm lost never had this problem before and I've been turning a wrench almost 15 years now.

by nothing do you mean no vacuum @ the line? If so it will simulate a bad booster. (same as when you lose brakes when the car shuts off) I run the big bore M/C on my wagon and it works great.

Make sure you have vacuum to the booster and make sure the booster bladder is/is not ruptured before changing it out.

 

[jbake]

Last night I took MS off double checked everything. Bleed the hole system. Triple checked I didn't hook anything wrong. Checks booster vacuum line. I've found nothing wrong. I even took my MS off my Monte to see if maybe I got a bad MS. Same thing.
Car idels good and run great for being a 267 with a 2 barrel.

 

[78MC-BBC]

with the engine running remove the vacuum line going from the manifold to the brake booster right at the check valve. One end should still be connected to the intake manifold and check to see if you have suction at the open end of the hose.

If you have vacuum at the hose end then plug it back into the check valve and now pull the hose off on the other side of the check valve and see if there is vacuum. That check valve is a one way valve only allows air to flow one way

If you have vacuum on both tests then the supply going to the booster is good.

Also make sure that there are no tee's in the vacuum hose going from the manifold to the booster. nothing should be pluged into that line except for the check valve

after you finish both testes turn of the engine get inside and pump the break petal, is it still hard to push. can you hear any wooshing sound like air escaping? if you hear air escaping then the booster is toast

 

[jbake]

Thanks for all the help guys. I did check the vacuum last night and had vacuum but did not listen for any house from booster after I hooked it back up. Was running late for family trip to Orleans. When I get back Friday ill check it. Maybe I did have senior moment case I didn't even think to check it. Lol thanks again n ill let you all know what I find.

 

[jbake]

K so I pulled both calipers off and think I've solved brake problem. The fluid to the calipers is good n clean but the fluid in it is sludge. Looks like water rust and 29 year old brake fluid. Wife on way to orileys now for reman calipers. $9.99 per side so to cheap not to just replace front brakes.

 

[78MC-BBC]

well at least you figured it out. I forgot how cheap the stock brakes on these cars were to replace.
Once you start upgrading the brakes then the prices skyrocket, once i put 2002 corvette bakes up front and add hydroboost it got expensive pretty fast, but a whole lot better braking

 

[jbake]

Thanks for the help. After I get Jr Buick up n running I'm going to do the ls1 swap on my Monte. Even the junk yard swap cost more than I paid for both of my gbodys. O well got to pay to play. Thanks again for info and help.