S14 brake problem

[terrence]

I have had issues with my brakes for about 2 years now and it is one of the main reasons I haven't driven my car. At first they felt normal but they would slowly lock up and wouldn't release until you bled the brakes releasing pressure and then it would roll again. After replacing the master cylinder and brake booster and an sr swap the brakes would work but they felt extremely stiff like there was no assist from the booster. So I recently (this week) got another booster and threw it on the car but to no avail. Basically as the car sits:

The brake pedal is really stiff, if you press on it, it will slow the car down but it takes alot of pressure and is not applying a lot of pressure on the calipers. It doesn't feel like it is slowing the car down much at all but it will stop it eventually. Basically unsafe to drive.

I have replaced the booster twice, master cylinder and check valve. I have checked for leaks and bled the brakes on multiple occasions. But I am still in the same spot, but at least they are not locking.

Any ideas at all?

[0wn3r]

What condition are the calipers in? Think they need a rebuild?

[terrence]

So, checked for vacuum leaks around the booster and yea, its not getting vacuum at all. Pulled the one behind the intake and rev'd the motor and no fucked up idle, no vacuum just nothing. So it is either clogged or something.

[z32boy]

I have an SR20det and when I accelerate hard and let off and try to stop the brakes are hard to press and will lock up. It's like the vacum doesn't build back up fast enough after boosting.