bone collector

ok guys ive searched and ive tried everything. i have a 94 v6 4x4 ext cab. ive changed the master cylinder, power booster, calipers, rotors, front pads, rear pads are still good and adjusted to the point where i have to use a hammer to slide drum back on. ive bled everything 6 ways from sunday and so many times i lost count. i have absolutely zero pedal. the truck will stop once the pedal is to the floor then it is full brakes. help me out im lost on this one. Thanks

waskillywabbit

iTrader: (-1)

Bench bleed the MC.
Bled the LSPV?
Bled in the correct order?

:wabbit2:

INFINITY

i vote micro bubbles out of the lspv. been there before.

bone collector

i bench bled the mc i bled the lspv. truck was sittin for 6 monhs before i got it. whats correct order??

bone collector

can i bypass the lspv?? just use a t- block like whats on the master cylinder??? how important is the lspv?? this is really frustrating. i have gravity bled the lspv for 45 mins then power bled it along with everything else. and still no pedal. there are no leaks anywhere. im really lost on this one

skypilot

iTrader: (1)

No; there is a funny loop-back to the lsvp. it takes effort and parts to bypass it.

I bet the MC is defective; its simple hydraulics, force in ,force out at the wheels. If the pedal goes to the floor all that "volume" had to go somewhere??? So it must be bleeding around the piston seals of the MC.

One thought; could your flex lines to the wheels be ballooning?

bone collector

i changed the MC, and bench bled it correctly. i will check the flex lines. any other ideas??

skypilot

iTrader: (1)

I have a 1990 Chevy Scottsdale with an "Isolation Dump" valve that is notorious for sending the brake pedal to the floor, part of the RWAL. Do you have ABS? or some type of RWAL installed? That might be dumping the fluid back thinking the wheels are locked up.

If the fluid is not being lost, all that energy has to go somewhere.

bone collector

i dont believe it is rear abs, but how can i be sure?? what is the correct bleding order?? i went rear driver rear pass, front pass, front driver lspv. correct ??? nothing has helped any ideas??

TNRabbit

That's correct order.

Either you have air or fluid is dumping somewhere. What brand MC? The standard parts store stuff is notorious for 1 in 3 being bad....

bone collector

the mc is an autozone special. i will pull it off and bench bled it again. and then bled the entire system again. if that doesnt work i will get another mc. thanks for ur help

rattlewagon

You can get rid of the LVSP and replace it with a manual valve. I think summit sells them for about 30 bucks.

TNRabbit

you should get an Aisin from MarlinCrawler or WabFab

oldblue

make sure the calipers are on the correct side of the vehicle. the bleeder screw needs to be at the top of the caliper, if not you won't get the air out. I've seen plenty of backyard mechanics loose their mind over this.

bone collector

Omg....thats it. i feel like such a noob. i didnt catch it when i changed the passenger side caliper. both bleeders are at the bottom. Doh! thanks for the help. i will change that asap. i feel like an idiot now

oldblue

haha, like i said, it's not the first time i've seen this!

bone collector

Teach me in the ways of the Yota master.....obviously im still a rookie. i cant belive i missed that with how many times i bled the brakes. now i need to go thru this entire new to me truck and see what other stupid things i can find.

TNRabbit

Wow; I learned something today. I didn't even know it was POSSIBLE to do that!! LOL

bone collector

Ya me either. in my defense i bought the truck 3 weeks ago with no brake pedal. whoever worked on the brakes put the calipers on the wrong side. they are exactly the same except the bleeders. once i swapped the calipers to the correct side it has great brakes now. thanks guys especially old blue. i still feel dumb for missing that little detail. of course thats where the devil is....

lozanojalpa

I ran into this prob. I had to pay a $300 embarassment. SOB i was so mad.