Brake booster or master cilinder problems

Pull the master cylinder and see if the front seal of the master cylinder is leaking into the brake booster.

Check ur master cilinder , a way to know if your wheels are free, jack it up turn the wheel by hand if not realese the bleeder on top of the caliper and try again if it is free probably u need to replace master cil.

when your brakes get hard 99 % of the time it is the brake booster if they get soft or spongy it the master cylinder

OK, a hard brake pedal is a good thing, in general. But, if the booster is not giving full power due to a vacuum leak, then stopping performance will be diminished due to the lack of vacuum assist.

Make sure the booster is holding vacuum by shutting off the car, locating the booster under the hood at the firewall, between the master cylinder and the firewall.

After a few minutes, remove the check valve from the booster by pulling it out. You should hear a loud swoosh of air going into the booster. If not, the booster may have a leak in it, or the check valve is not working.

Good luck on diagnosing the hard braking problem.

Did you bleed the line for air? If the break line was by the master cilinder, got to bleed all 4 tires, otherwise, got to bleed the two front or two rear tires.

If you step on the brake and feels spongy, is probably air in the lines, if it feels hard check master cilinder, if you hear an air leak, check brake booster.

If it's really hard and you cannot hear the booster making noise or it make alot of noise then I'd suggest getting a booster. Also MOST of the time the reason the booster goes bad is because of the master cylinder leaking fluid into the booster. If you take the master off and look into the booster and see fluid then replace both. If it has no fluid in it and the master looks good, then most likly the booster is the only problem!

IF your booster is vacuum operated,not a hydro-boost 7 IF you can mount it & IF you can plumb it,properly bled,it should be compatible.

Two issues...
The brake booster has a ruptured diaphragm. Replace the booster.
It is located under the hood between the brake master cylinder and the firewall.

Your master cylinder may be leaking fluid internally past the plunger.
Have it examined when you change the booster.

Might be the power booster located behind the master cylinder