brake problem...possibly the booster???

[kefferjoe]

So on my 86 300zx I seem to be having a braking issue I can floor the brakes and still only stop very slowly...I have mAde sure there are no air bubbles in the lines and there is NO fluid loss...however when the car is on and you press on the brakes I can hear air come out from around the pedal more specifically the rubber boot that most likely goes into the brake booster I replaced the vacuum line in the engine compartment because it was cracked but the brakes still don't work and I am out of ideas any help is appreciated

[evildky]

might be a bad master, with the car off, if you press the brake pedal is ti still soft? if so it's the master

[kefferjoe]

definitely not seeming to be the master cylinder...i don't want to dump $250 into a new brake booster if its not the problem is there any way to test if it is broken?

[ravera]

You might have had the reaction disk fall out, it's a little rubber disk that sits in the booster. If you pull the thing apart it should be firmly stuck in the booster by the plunger to the master.

[evildky]

see if the booster holds vac, if it won't hold vac it's bad, if thats not it pull the master cna check the reaction disk

[kefferjoe]

If the reaction disk did fall out can I just put it back in place??

[evildky]

yup, you just gotta fish it out fo the booster

[kefferjoe]

ok well turns out the booster problem was due to the large amounts of fluid inside of it so that obviously means issues with the master...has anyone had luck replacing the seals on it or should I buy a new one??? Dealer says new one

[evildky]

you can get remanufactured units about as cheap as a rebuild kit and there is a possibulity tat the leak is due to a scratch int he cylinder bore thats too deep for a brake hone, rockauto has some really good prices