front wheels still lock up after a good use! any ideas

ok, cool.. i thought it was that end i had to cut, heres what i did, i cut about 1/4 off.. when you pushed the booster shaft inn, the shaft came out along with a black sleve. what i did was cut the round tip off and just left it flat along with the black sleeve that comes out..i did not round it, any problems with not rounding it, i tried the brakes without using the car and seems to work good, should i cut the sleeve off and then round off the tip or just leave it flat.

 

Round it off as closely as possible to what it was.

 

but i have to cut the sleeve aswell right, kind of like peeling it off...take off the sleeve, then grind the shaft round.. is the sleeve plastic or metal.

 

I'd round the end that goes into the back of the master cylinder, and trim the sleev as needed to clear the part you've rounded.

-Josh

 

so i did that today, does not lock up anymore...:TU: but noticed the brakes feel good but when u use the car, it feels like about half way its running without a booster, say first half down it feels good but does not brake that well, and past half. it feels hard as if it had no booster. but brakes alright, not the way it should be though, could it be the booster, if i were to just leave this alone and just buy a booster, should it just be for the for the 72 skylark with disc brakes.