brake trouble in my 84

here are the symptoms:

firm pedal
front brakes grab/lock up
pedal gets more firm as heat builds

Heres whats already new:

front calipers
pads
rubber brake lines
master cylinder


The only thing that is not new is the brake booster. I am leaning towards putting on a new booster because if I take the vacuum line off (plug the line and booster fitting) and then go driving besides having manual brakes they seem to work fine(no grabbing/locking up). After I put the vacuum line back on the booster it worked like it should sporadically for two days then it got real bad and locked up the front to where I could barely drive it home.

Could it be a problem in the vacuum system somewhere else away from the booster causing this or is there any adjustment in the amount of vacuum?

Ideas???

 

ok so I know the check valve is a 1 way valve. unhook the end from the carb and blow into the hose (no jokes needed here) towards the booster and that should work??

that doesnt make good since to me, of coarse i dont really know what i'm doing here, but when I take loose the booster end of the hose there is constant vacuum through the hose(engine running) like the valve is always open in turn always pulling air through. could the check valve be in there backwords???

 

the check valve is in the middle of the firewall not on the booster itself.... so it could have been messed with at some point.

 

ok so the "inline" valve is correct.... I may just go to auto zone and throw down on a new booster tonight....

It has to be the check valve in the booster or something in the not equalizing pressure because the pedal is so firm and gets more and more firm locking things up

 

lol thanks for the replies. Plan activated.....

 

did some more testing after work. this time it seemed not to matter if the vacuum line was connected to the booster or not, the front brakes just wanted to grab/lock up. is it possible for the booster to just be stuck or maybe the spring that makes it equalize pressure is broken, or maybe......

oh by the way that white in-line valve in the booster vacuum line only lets air go towards the engine, it does not let air pass back to the booster