so im cruising home from my friends place after a complete t2 swap, and my brake pedal went out as if i lost pressure in my system, so i geared downs to slow and eased on the e-brake to a stop. WTF!!! sounds like the vacuum line to the brake booster has a leak either before or after the one-way valve......... my question is the following, can it be the brake booster gone bad?!!!! how can i tell, i hear a noise around the one way valve or the booster not sure, i was shitting bricks at the time......

 

Damn! That's crazy! Does it only happen after you put load on the engine? Or is it all the time? When I first bought my car, the owner forgot to tell me it didnt have a check valve on the brake booster, I boosted and afterwards brakes didnt work AT ALL! Almost ran into a car because I couldn't stop at a stoplight. They sell aftermarket GM style brake check valves at autozone for like $3.99 if you find that to be your problem.

 

wow good thing you are save, scary stuff

 

^

i is save bro you thanks :P

well i bled re bled the system. theres no air in it at all, and its all the time. but yea im seriously thinging its the bloody check valve

 

huh?

does the pedal go to the floor? or does it not move at all. or moves only with alot of effort?

 

it has enough pressure to spring the pedal back up and at all times its super soft, i pump it and i feel it build pressure but not enough..........

 

Bad brake master cylinder?

 

I had the same thing happen to my s14, I almost died. It sounds like the master cylinder to me as well...

 

Pull the hose out, try to blow from both sides, see what happens. This will tell you if you have the check valve.

With the engine off. Pump the brake pedal a few times. Each time, the pedal should stay a little higher. On the last time, hold the pedal, and it should stay in the same position if the hydraulic system is fine. Start the engine, and the pedal should go down a bit if the rest of the brake booster system is working. If all checks out, your check valve may be indeed missing or bad.

Are you using the NA brake booster (since you mentioned a TII swap)?

Also a good time to check for leaks or a dropping fluid level. I know I'm bouncing from cause to cause, but you should check the whole system, even if it turns out to be the check valve.

Good to hear nothing got into your braking distance.