project91

my 91 truck has a very stiff brake pedal..and minimal braking taking place..any ideas...?

904_runner

hows the fluid? did this just start?

project91

Fluid is topped off..new shoes/wheel cylinders in back...this was the inaugural run of the 3vz v6 swap, so I was wondering if the vacuum boost has something to do with it...I unhooked the vacuum boost, still stiff.

904_runner

im not sure what to tell you. did you use the v6 calipers/ well the brake components?

project91

Not sure if thats the issue...I unhooked the master cylinders vacuum line that goes to the intake manifold and its still hard as hell.

Yoda

Your symptoms sound like a bad booster.. Do you have vacuum at the hose at the booster? Maybe the check valve is bad in the hose (on our 85 truck)?

project91

gonna check on the check valve becasuse when I pulled the vacuum line off withit running....there was no vacuum on the hose.

Yoda

No Vacuum will act like a bad booster

kramykram

^^^ What he said!! Without the vacuum boos you will have no hydrolic pressure. If you have no vacuum on the hose when you pull it off the booster you will have no brakes. The hose should suck you finger and pull strong, it should also effect your idle. If you do have vacuum and still have a stiff pedal you may have a leaking MC into the booster not letting the diaphram do it's job.

project91

I done an engine swap, so the vacuum booster hose sat in the engine bay of my truck for about a month, unhooked. A bug had crawled inside and built a "mud" seal in the check valve....I cleaned it out and hooked it back up and "BAM" brakes again..thanks alot folks!!!!!!!!!!

904_runner

good, glad you fixed it! i think you need to post the pic of the engine you posted on ttw! that thing is so CLEAN!!!!!!!!

project91

Here it is..surprisingly it has better power and mileage than the 22re..I like it!