hello all: new member here and just purchased a 1993 s-10 blazer,4wd. 65k original miles. with ABS

and it has a soft brake pedal.minimal braking and pedal goes almost to the floor. i purchased as is, that way.

previous owner replaced several rusty brake lines and after bleeding brakes had this problem. he then installed a new master cylinder.

same results.after bleeding system,has minimal braking and pedal goes almost to floor.

i bled the brakes at all 4 corners yesterday using correct sequence . i,with an assistant, pumped 2 quarts brake fluid thru the system. same results.

my question is:: has anyone removed the ABS from the brake system?? or tips on abs removal?
thanks in advance for any and all reply's.......larry...

 

Does the red "BRAKE" light on the dash come on momentarily when you turn the ignition to the RUN position, or does it stay on?

 

when i turn the ignition switch on:"brake" light and "abs" light come on and then go out in about 4-5 seconds.
thanks for reply........larry.........

 

Cool, that means the centering valve, (proportioning valve) is centered, which is how it needs to be to bleed all 4 wheels.

Low, mushy pedal means there is air trapped, no doubt Need to start at the master cylinder and work outward from there. Was the master cylinder bench bled before it was installed? If you're not sure, it needs to be removed and done.

 

i am not sure how the master cylinder was bled. i will remove and bench bleed tomorrow. and then bleed the 4 wheels again.
will report back here my results.
thanks for information.......larry.........

 

Not so fast After the master is bench bled, reinstall it and fill it up. DON'T touch the brake pedal. Leave the cover off and open the right rear bleeder valve. Let it gravity bleed for ~20 minutes or until the fluid comes out clear, no bubbles. Close the valve and move to the left rear and repeat. Then the fronts, one at a time, until there are no bubbles from any of the bleeders. DO NOT let the master cylinder run dry during all of this. Once all 4 are done, have an assistant apply pressure to the pedal, don't pump it. Quickly open and close the bleeder while pressure is applied. Don't allow the pedal to go to the floor. Repeat until no bubbles. Repeat at each wheel. Cross your fingers and post your results.

 

thanks for replys.i removed the MC and installed a rebuild kit. (it looked like a new MC on the inside)
and then bench bled until only pumping fluid.and reinstalled.

gravity bled the 4 wheels .got a lot of air out of all 4 wheels.and then pressure bled using the foot pedal. no air came out when i used the foot pedal

however,no joy.
still have a low and soft pedal with very little braking.

no waning lights are coming on except briefly when ignition switch is turned on.

i believe my problem is in the abs component,on the fender,beside the MC.

i am considering bypassing the abs system and rerouting the brake fluid lines.

Anyone done this successfully? thanks in advance for any and all reply's.

 

Mush pedal means there is still air in one or more hydraulic circuits. Pumping the pedal on that system to bleed it, will bring no joy Gravity bleeding is the answer, and leave the master cylinder cover off. Could take a quart or so of fluid. You can try using a hand vacuum pump on each bleeder to speed it up.

 

This guy knows what he is talking about, do the sequence bleed for all 4 wheels using the gravity bleed method. Use a hand pump if needed like Cap Said... but I found those to put a cramp in my hand.

There is definitely air still trapped in the system.


Cap... curious, if the fluid got too low, do you think air could be trapped in the ABS system, if so, wouldent they need a special code reader to bleed the ABS system?

or is that a different situation?

 

gravity bleeding from the rears was very very slow.
like one drip each 2-3 seconds.

so i ordered a mityvac 8000. will see how that goes.

..............thanks....larry....