What's up with my brakes?

[randito]

I've been dealing with some brake issues for a while now on my 86 pickup. When I bought it, the MC was leaking so I replaced it with a brand new one from Toyota and thoroughly bled everything. Now after I brake hard, the pedal initially won't push down far unless I really stand on it. Then it will catch up high then push all the way to where it is supposed to. But it keeps doing this catching and then pushing all the way down, very harsh. If I drive a while, it will brake properly again.

I figured that maybe the pushrod that comes out of the booster needed to be adjusted to go with the new MC. So I did that, but the only way that I could adjust this problem out of the system was to have the pedal engage really high up, almost to the point that I was worried about there always being pressure in the lines. Any ideas or similar problems? Thanks.

 

[WristPin]

take off the front wheels and check all 8 pistons on both calipers to see if they all push in evenly, with out sticking.

make sure the rear shoes are adjusted properly.

make sure no lines are kinked, and no hoses are swelling.

adjust the pedal free play to specs. this ensures the stroke is correct.

are you 100% that master is correct for your truck?

call another dealer, talk to the parts manager, and double check the number.

if you have a master designed for 4 wheel discs it has a residual valve not designed to operate with drums.