I have a 96 S-10 4.3 auto when I press my brake pedal to the flr it sticks causing my brakes,to lock up when running. but when I shut motor off brakes an pedal releases what would cause this. Don't knw when they do lock up.

 

maybe a bad booster....unplug the vacuum line to the booster and see if it works better....you won't have vac assist obviously

 

Ok I will try this this evening. If my booster is ok u think it could b my master cylinder

 

It especially does this n cooler weather not so much n warmer weather

 

Brake booster is ok

 

maybe the check valve is sticking open?

 

Ok I will check that this,evening

 

Im just going to replace the check valve an hose instead of checking an go frm there. That way i knw that part will b new.

 

My rear drum brakes r acting strange when I come to a,stop going forward instead of coming to a smooth stop it grabs,an tries,to lock up it only does this on my left rear wheel could it b my wheel cylinder it's not leaking fluid.

 

I checked my check valve it's working no air leaks. Never done this before.