9 replies to this topic

[HiZ]

Here we go
It is 3:45 am I just finished up a full brake job on my 93 GMC Burb
Replaced:
Front~
Rotors
Pads
Calipers
Hoses
Rear~
Shoes
Hardware

Front and rear fluid

I put all new stuff on and used a vac pump to evacuate all the fluid and put fresh in the system
the brakes were always better than my 98 and ABS worked perfectly
After replacement of all components the brake pedal will go to the floor with minimal resistance
the master res never was low on fluid, never had any issues with the lines
I used an electric puller vac to evacuate the fluid in the system
~also when depressing the Brake pedal fluid will Push/Stream up and out of the rear res of the Master

What is going on

Help
I have an idea but what you think is what I am curious about


Thankyou

[NickV]

You have air somewhere in the system.

When you say you evacuated the fluid, did you drain it dry or suck in new fluid at the same time? In other words, did you ever suck air into the master cylinder? Hopefully you don't have air in your abs pump. If so it would require a Tech II to pulse the system and bleed the air out.

[HiZ]

I have access to a TECH II
I did not let air get into the system at all
I used an electric pump with 2 of us on each end keeping it full

My question is WHY: when the brake is pushed, does fluid come up from the master main/rear passage like a water fountain/bubbler?

[Squirrely]

did you manually adjust the rear drums out as far as you can? It's a pain but must be done.

If not, that will cause your problem

[HiZ]

did you manually adjust the rear drums out as far as you can? It's a pain but must be done.

If not, that will cause your problem

I was thinking the same thing

[Squirrely]

Simply put the drum on and smack around it with a mallet to center everything up. Then pull the drum back, but not off, just enough to get your finger on the star nut. Spin it out till tight and repeat the whole process till you're maxed out.


If you pull the drum all the way off then you might have to start over.

[govtech4]

I have access to a TECH II
I did not let air get into the system at all
I used an electric pump with 2 of us on each end keeping it full

My question is WHY: when the brake is pushed, does fluid come up from the master main/rear passage like a water fountain/bubbler?

tech 2 is not used on a 93 anyways ,,,so dont worry about that misinfo

you let air in when you replaced lines and calipers i would think,


loose the vacumm crap,set up rear shoes and bleed it manually ,,,

open bleeder,, push to floor slowly1 time ,close bleeder ,release pedal, repeat

you MAY need to bench bleed the master cyl if that doesnt work,,,but that is unlikely

no smacking anything ,sorry squirrely !

the fountain thing is strange,how far does it spray out ????

Edited by govtech4, 06 April 2012 - 08:09 PM.

[Squirrely]

no smacking anything ,sorry squirrely !

the fountain thing is strange,how far does it spray out ????

twas the only way to get my shoes to fully adjust. no biggie to me. I swear

The fluid thing has happened to me. I was pumping the pedal way to fast and it threw fluid up and out from the master. Got the fluid all over..... Yup, I seen it before.

Edited by Squirrely, 07 April 2012 - 10:10 AM.

[HiZ]

Fluid came out like a bubbler, just overflowed from the master splattering it all over
I think that it was the rear adjusters/making adjustments to the system via the inspection cover it now is much better
Thank you,
I still want Answers to the master cyl flow

[John's Trucks]

Vacuum bleeding is iffy at best (don't ask me how I know ) pressure or manual bleeding is more reliable. Did you pump the brake pedal all the way down at any point? If so, you may have buggered up the master cylinder seals. In normal use the seals never see anywhere near the end of the M/C bore, so over the years the unused part of the bore gathers crud and rust. If you go anywhere past that point when pumping the brake pedal when bleeding, the crud and rust can damage the seals which means a new M/C. The way to avoid this is to just use small strokes when pumping up the pressure.

Edited by John's Trucks, 08 April 2012 - 11:10 AM.