Super Stiff Pedal, Brakes only Sorta Work

[Panopticon31]

Recently acquired a 1991 S13 that needs a little work.
It has a 5 lug swap already, I am assuming it is a 300zx swap.
The brakes reaaaaalllly dont work that well. The pedal is SUPER stiff and I would say pushing as hard as you can you get maybe 30% of normal stopping power.

With the car off pumping the brake successively does nothing, its really stiff from the first pump to the last.

Before i start digging I wanted to get some opinions. I am thinking it sounds like the brake booster is shot but would like to hear what you guys have to say.

Thanks.

[centralcoaster33]

I'd at least spend some time bleeding out the system with some fresh brake fluid. While bleeding, I'd give the system a visual check. Then I'd test. Then I'd look into a vacuum leak at the booster vacuum line and intake. Then I'd look into the master cylinder... and so on. What have you done so far besides drive it and pump your brakes? Can you try the above?

[Panopticon31]

Don't have the equip just yet for bleeding. Just got the car a few weeks ago and was waiting for the Texas heat to die down a bit before starting on it haha.

I will get a hand bleeder and start there though.

Thanks.

[PapaSmurf2k3]

Yup, definitely sounds like a bad brake booster.
I've had the same thing happen. Nice stiff pedal, no braking assist.

[Panopticon31]

Yup, definitely sounds like a bad brake booster.
I've had the same thing happen. Nice stiff pedal, no braking assist.

Thanks for the info definitely what i am running into.

With 227k on the odo i think i am just going to replace the booster and master cylinder just to be on the safe side. new fluid goes without saying.

[PapaSmurf2k3]

Definitely.
A lot of times the master will leak fluid out the back and contaminate the booster/blow some seals anyway. You're probably due for both. Make sure your check valve in the booster line is working too, and that your booster is actually getting the vacuum it needs

[JustinRB25s13'92]

Usually,
Not in all cases, but usually a stiff pedal is due to brake booster so I agree with PapaSmurf2k3 on checking that out... Another key to a leaking master is if there is what looks like corrosion or rust or galled metal on the face of the booster just behind or underneath the brake master cylinder, it would look as if something had been running down. typically thats a dead giveaway to a leaky master to begin with. Atleast from what I have found and experienced..