Brake pedal goes to floor

[bludmon]

Hi everyone! My name is Mike and I have a question about my 2002 Ford Explorer Eddie Bauer Edition. I just had the master cylinder replaced and my pedal still goes to the floor. My mechanic is stumped! He has tried everything he can think of and he doesn't know what to do next! So far he has changed 3 calipers, all the rubber lines. He capped off the master-and deadheaded the cylinder and got a rock hard pedal. He hooked the lines back up, cycled the ABS with the scan tool, bled, cycled again, bled. Checked vacuum in booster. Took apart ABS, cleaned the valves, reassembled and installed, bled. The pedal still goes to the floor. He bought a used ABS, installed it, bled and the pedal still goes to the floor. The Explorer does stop and stays stopped but the pedal goes right to the floor. My mechanic did all this and still ended up with the same result!

Please help! I love my Explorer and with 239,000 miles it runs great but we can not figure out this braking issue! I would appreciate any help you can give us on this problem

 

[FordFlintrock]

Assuming the pushrod is properly adjusted to the master without it too long or short. Do you get a good strong stream of fluid out of all bleeders? Has a vacuum bleed been tried? Is everything under the dash correct with pedal and booster and pedal stop leaving pedal too high off the floor? Are u still getting air after multiple bleeds? Calipers wrong or upside down, bleed screws on top? Getting booster vacuum on master?

 

[bludmon]

Assuming the pushrod is properly adjusted to the master without it too long or short. Do you get a good strong stream of fluid out of all bleeders? Has a vacuum bleed been tried? Is everything under the dash correct with pedal and booster and pedal stop leaving pedal too high off the floor? Are u still getting air after multiple bleeds? Calipers wrong or upside down, bleed screws on top? Getting booster vacuum on master?

Thank you for your reply FordFlintrock! I will forward your ideas to my mechanic. Have you ever heard of this before? Basically anything that can be replaced has been replaced! All the rubber hoses have been replaced, all calipers. He is bleeding the brakes with some kind of brake bleeding machine. He replaced the master cylinder 3 different times thinking that is what it was. He said he checked the booster. The brakes do stop the car but still go to the floor. As I said he even replaced the ABS module with a used one and still got the same results!

 

[FordFlintrock]

Are the hub/wheel bearings shot pushing caliper pistons inward? Are the rotors/hubs running true? With a helper as a pedal pusher I would expect to see a nice 14-24" stream out them bleeders.

 

[J_C]

After I did brake hard lines, 3 calipers, and soft hoses on my '98 (all at once), I tried to bleed and only had partial success. Pedal didn't sink all the way to the floor but was real spongy and extra travel.

I tried bleeding again, 2nd time and got a marginal improvement, but ultimately I just drove it gently for a while and there must have been air that worked its way out, up through the master cylinder because it returned to normal without having to bleed a 3rd time. I did take it onto gravel and did some braking to get ABS activating, but did not notice an immediate improvement right after, still more driving (not a lot, guessing maybe 5 miles stop and go over a few short trips) till it returned to normal.

I don't want to encourage you to drive it if it's not safe. I was taking it easy.