flaunt

I got a 94' 2wd Toyota Pickup. Turned into a prerunner.
Im currently running 4x brakes up front and a T100 Rear End.

The brakes worked fine before i tore the truck down to get it ready for this upcoming season, upon putting the truck back together I went to bleed the brakes and they would get hard but not stiff, and when bleeding fluid came out just fine and air was completely out of the lines.

I sucked down atleast 4 tanks full of brake fluid..and zero leaks were found.
Whats the issue here?..is it my booster?..master cylinder?

Im currently in the midst of my 3.4 swap not having a motor in it wouldnt be a issue right?

Any help is appreciated.
Thanks!

myyota

You have to have the engine running and vacuum to the brake booster, otherwise the brakes are going to be hard.

Zelephant

Blake fluid can leak from the master cylinder into the booster, it happened to me. Pull the booster, hold it upside down, and see if fluid comes out the vac line hose mount. If so, you found the leak. Dunno about four tanks of the stuff, though.

Correct me if I'm wrong, but not having an engine in there shouldn't matter when bleeding brakes. You just won't have power assist.

91diesel

I had the same problem on my 91' 4x4. Try adjusting the rear shoes out. If they are not far enough out the brakes will feel like they need bled, including 'pumping' them while driving to get a firm feel. But for me all it needed was the shoes adjusted out and the pedal felt great.

flaunt

Thats the problem the brakes arent even geting hard, they start to build up then the fluid goes low and all the pressure goes away.

I was thinking what Zelephant said that the fluid is leaking to somewhere else and is resting, I know all the fluid isnt sitting in there because it came out as i bled so theres some of it going somewhere else.

Still clue less. Unless anyone else knows whats up?

camo31_10.50

well OBVIOUSLY the fluid is going somewhere..

so if there is NOT a puddle of brake fluid somewhere...(or in the floorboard...leaking down from the master cylinder on the inside of the truck) then it's likely leaking into the booster.

flaunt

Well duh its going somewhere I knew that I'm just saying its resting somewhere without keeping pressure.

So all of this might equal to that my master cylinder is bad or booster?

ab_mekanik

by now, it's both. If you still have that load sensing proportioning valve in the back, you might want to try there as well. Have you checked your wheel cylinders?

if there's no engine installed, it'll be easiest to check the MC now. No, you don't have your engine running to bleed the brakes, in fact, that's the wrong way to do it.

tried4x2signN

Have you removed or replaced both calipers recently?

Awe heck, I'll just tell ya...

I just went through a fubar... Grabbed the wrong caliper for the wrong side...

Shoulda went with my gut but didn't. Couldn't bleed the caliper... DUH! It was the wrong one and the bleeder was at the bottom of the caliper... Not at the top where it should be, so the air can purge out of it.

clydehatchet

have you bled the master cylinder and or the LSPV?

flaunt

haven't bled the mc or the lspv.. didn't even think that there might be a problem there... its just so weird to me that the truck was fine and braked fine, then once I put everything back on and try to bleed the brakes again they wouldn't get hard.

flaunt

any other input?

thinking of just getting another MC.

any input on a aftermarket one or just try to get my hands on a factory MC?

Foglifter

I recently replaced the hard lines and first time around didn't bleed the proportioning valve. Pedal was to the floor. Bled the valve second go around and bingo. Pretty much foam came out of the valve. DOH!