Mushy Brakes

[WDP]

Yes I did hit the search hard so here goes. 2004 AWD XLT. The pedal was soft and would sink to the floor with moderate pressure. Replaced the rear pads and rotors, no diff. Decided to flush out and bleed the system, no difference. Replaced the master cylinder and reflushed and bled the system again. Still about the same, tried a mighty vac and bled the system again, got more dark fluid out of the fronts. Took it out on a dirt road and got the ABS working, pedal goes to the floor. Did a manual two person bleed, after the vacuum runs out the pedal is right at the top and firm, start the engine with moderate pressure, pedal drops almost to the floor, no amount of pumping will move it back up. It is hard to believe there is air in the system with all the bleeding I have done, someone have another area to check? Thanks in advance.

WDP

 

[Jd0gg919]

Have you tried bench bleeding the master cylinder? Maybe there's some air still stuck in there.

 

[WDP]

Did the bench bleed per instructions, didn't have a hope of getting it all without a regular bleed procedure, or two.

WDP

 

[ld50]

How's your soft lines in the system -one at back to rear diff and two up front feeding the front calipers(?).
Seems like you have everything covered (everything is new!)but perhaps a soft line is bulging somewhere. Long shot but If not, then you have to have air in the system somewhere, or you have a faulty new master cyl.

 

[XtremeRanger]

YEah, im with ^^^ I say faulty Mast Cyl....

 

[WDP]

More- did the two man bleed again, not bubble one, the rubber lines feel ok both with and without pressure. If I got air in the ABS can they be cycled in hard stops on gravel and blow it out? Starting to look like ID and the Ranger have it. Maybe the rebuilt is shot . Still up on blocks if some one can throw another idea at me. Thanks

WDP

 

[ld50]

Wouldn't be the first time a replacement master cyl was already shot..
It could be leaking past the seals and be totally internal and you can't really tell.
I`m not sure about trapping air in the ABS. I've done a lot of work where I have had to bleed that system and never had a problem I could attribute to that.