my brakes just died for no reason

[wimpytwins]

i have a 93 explorer with abs. two years ago i put in a none abs rear axle and also a solid axle up front. it has been fine for the last two years and now out of no where my brakes dont work. when the car if off i can push on the brakes and the pedel get hard after a few pumps. when i start up the truck the brake pedel go soft and i can push it to the floor over and over. i have replased all of the lines and i have bleed them a dozen times. i have check for leaks and there arent any. could the abs modual just go bad? shoul i bypass it? what do i need to bypass the abs if that is whats it is?
thanks for the help

 

[Ford_Racing_Guy]

i'm thinking that brake master cylinder needs to be replaced,

do the brakes work while moving if you pump them up and then does it feel like the pedal goes down and your losing pressure?

 

[410Fortune]

Sounds like your master cylinder has been bottomoed out.
also a good time to check the vacuum in your booster or replace it.

If you replaced the rear axle with a non ABS version and the same is true up front you should remove the ABS module, run new hard lines, and get a master cylinder built for non ABS trucks. If you have rear discs you should get a 95 Explorer master cylinder with no ABS, bolt it on, bleed and go.

Your problem seems to be master cylinder related, but it could also be a bad booster or vacuum.....

 

[wimpytwins]

everything was working fine for two years and last week i put in new pads up front and i used a c clamp to push the brake piston back in and put everything back to gether and now there is still nothing. i read that if i get a air bubble into the abs unit there is no way to get it out unless i take it to a dealer. is this true? if so can i bypass it and use my same master cylinder even through it isa abs one? if i have two replace my master cylinder do i need a adjustable valve for the front and rear brakes? thanks for all of the help. one other thing is my transmistion slips in and out of overdrive but all of the other gears are fine and if i leave it out of overdrive everything works great. thanks again

 

[410Fortune]

The air will come out of the ABS valve

Still sounds like you bottomed out your master cylinder, you might have also blown your front calipers.

 

[Mbrooks420]

You pushed the caliper piston in too far and damaged something, or have trapped air. I wouldn't call that no reason The light duty aluminium overdrive unit in the tranny is probably starting to go. They aren't very stout, and fail often.

 

[DeRocha]

I have read you need to be careful when compressing / seating the caliper piston. If the brake fluid looks bad then you could force all the bad fluid back through the lines and have it contaminate the ABS controller. One procedure recommended you open the bleeder valve on the caliper so that you will expel the old fluid instead of pushing it back through the lines.

 

[wimpytwins]

today i found out that my brakes would work in reverse but would go back to nothing in forward. i took off the master cylinder and found that only one port out of the two would shoot fluid. i went to the parts store (autozone) and bought a rebuild master cylinder and found out that it wouldnt even prime before i put it in luckly. does all of this sould right except for the bad part?. thanks

 

[urbanistic]

The seal on the power booster had a recall from the dealer. I would make sure you have the right seal. Ask a dealer for details.

 

[410Fortune]

what does I found it wouldnt even prime before I put it in mean?

Meaning you bought a Autozone master cylinder and when you went to bench bleed it you found it didnt even work?

Dont EVER buy somethig as important as the master cylinder from Autozone.
In fact dont buy anything electrical or hydraulic that is rebuilt from Autozone, ever...

 

[urbanistic]

ya dont buy rebuilt!

 

[wimpytwins]

i bought i brand new master cylinder and got rid of the abs all together. all the back brakes are working great but the front brakes still have no presser. there are no leaks in the system. does this mean that the calipers are bad even thow nothing is leaking from anywhere.

 

[410Fortune]

what master did you get?
Hows the booster, got vacuum?

You have a solid axle up front, is it a D44?

The biast from front to rear is adjustable on your truck. The plunger that comes out of the booster and acts as the pushrod for the master has an adjustable nut on the end, the length of the rod determines the front/rear biast.

Do a search, sounds to me like you could use more front biast.
Also when you say you ditched the ABS did you plumb new hardlines in place of where the proportioning valve used to be, or is it still there?