Brake pedal pressure.

[cracka400]

Hello all,
It seems as though I fix one problem and another arises. Anyways, I replaced the rotors, pads, and calipers for the front on my 89 coupe my buddy Zach-Ka is driving. What the main issue was, the front right caliper seized up about a week ago and started all of this. So on to the big issue. I changed out all of that stuff and now the pedal will build crazy pressure and lockup the front brakes. I've changed the booster, hoses going to the booster, check valve, and a.i.c.v. assuming that would fix the issue. Btw, all the parts came off a working car. The crazy thing is, the brakes will do fine for about 5 min of driving and then boom idle spikes up a bit and then the pressure will build up. This situation is blowing my mind entirely. I do not understand where all this vacuum is coming from to amount that kind of pressure. Anyways if anyone has had or have seen an issue like this please help because I don't know where to look next. Thanks guys.

[PapaSmurf2k3]

There was no change after changing the booster?

The only other thing I could think of would be the master cylinder... does it lock up both front brakes? Are you getting any braking power to the back of the car?

[cracka400]

No there was no change with swapping the booster. And yes it locks both front calipers down. Zach-Ka and I were talking earlier and we do believe that it sounds like a master cylinder. Oh and the rear brakes feel as though that are working fine. It just seems so odd that it will do it on and off at different times.

[PapaSmurf2k3]

Yeah, that is weird. Unless you are boiling your fluid or something...

[zach-Ka]

I was studying the inner workings of the master cylinder and the front brake lines have their own piston inside the cylinder and the rear lines have their own. I think the spring that is supposed to make the paticular piston return when you let off the brake has taken a crap. So that would cause there to be constant brake pressure to only the front when it has warmed up. IDK though...