the_ocho

Okay so when i bought my truck the guy told me that he had blew out the break line to the lpsv and when he replaced it he never got the rear breaks to work again. I figured I would start small and try to bleed the system properly so I went to the driver rear wheel and nothing came out. so I figured I would jump straight to the lpsv bleeder and nothing came out of there either. so I disconnected the line that he had installed that ran into the lpsv and it had pressure to it. so I'm thinking that some sort of junk got into the lpsv when he had the line off and plugged it up. so i was wondering if the lpsv could be easily rebuilt or at least taken apart and cleaned? or would i be better off trying to find a different one. Any help would be greatly apriceated. its starting to snow and no back breaks for my first winter outside of CA where it never snows isnt that good of an idea.

Bigblock

I omitted mine.Ran straight from M/C to rear brakes.BUT I don't live where it snows!
Bigblock

the_ocho

yea i think the 50/50 is a lil too strong for the ice/snow

abecedarian

one line to the LPSV comes from the rear circuit of the master cylinder
the other line to the LPSV comes from a 'tee' in the right front brake line.
the 'bleed' valve is supplied fluid from the line from the right front brake.
if nothing came out of the bleed valve, I think you've got a lead to follow.

Bigblock

Do you trust your ABS?LOL

the_ocho

the light is on, so no

the_ocho

Yellow= bleeder has no pressure to it.
RED= the line that he replaced and has pressure to it.
Blue=?
Green=?

you said one comes from the MS and one from the T in the front. and logicaly the other goes to the wheels. can yo tell me which is which?

abecedarian

it's too dark for me to trace down all of it but I can say that the port at the top of the LPSV, the one you have circled in red... is supposed to go to the rear axle, not receive pressure from anything.

the_ocho

ok so i decided to man up and go outside and look at mine again. laying there in 3 inches of snow under my tuck with a lighter to see. i did see what he did wrong. the red is supposed to be the output the the softline. if one of you can help me out so i can figure out what is supposed to plug into the green and blue on my diagram i would love it.

the_ocho

what size are the break lines and fittings?

Cyberman

I replaced the hard line going to the soft line as well. I didn't know the size, but when I went into the parts store, they gave me the "standard" size, which was the correct one.

I had issues with bleeding the rear as well. What happened in my case was that the bleeder was clogged. After loosening it almost completely, it finally gave way.

I do know that it is a pain to bleed the brake system properly. According to the FSM, the initial bleed is actually done with the engine running, due to the ABS actuator running off the power steering. Even after doing that, I still don't think the brakes are bled properly. My mechanic also said I was on my own, because of his past experience in trying to bleed this kind of system without success.

Maybe someone else here knows the trick?

Bigblock

Never had any problem.One person to mash the pedal and one to operate the bleeder.Air goes up,liquid down.I use my finger as a check valve by placing it over the open bleeder while the other person pumps the brake pedal.Engine off.Take your time pumping too.The fluid cant move as fast as you can pump.Dont let it run out of fluid in the M/C or you'll have to start over.
Bigblock

abecedarian

I think the problem here is the anti-lock system. Have you checked for related codes?
http://personal.utulsa.edu/~nathan-b...14diagnosi.pdf

the_ocho

Guess who has back breaks....yea THIS guy I went and bought a 2 foot section of line from the auto parts store ran it from my softline to the correct spot in my Lpsv and connected the line that the PO ran to the correct spot in the LPSV and started the bleeding, and i got stopping power in all four corners and must say what a difference. its still a lil soft so I'm gonna bleed them again and then hopefully it will stiffen up.


And yes i do have my Anti-lock light on. I haven't yet looked at the codes but have been reading up on it in the FSM that will be my next project on this never ending project.