OK, I am so frustrated. I have bled my brakes about 7 times already and the pedal is still spongy...goes almost right to the floor (when the engine is running). The pedal was very firm before I installed my speed bleeders and changed my brake fluid. Since then, the pedal is really soft. I have bled the brakes several times since. I have done a one man bleeding multiple times (taking advantage of the speed bleeders), and today I even had my Dad come over to help me do a traditional 2 man, manual bleeding. When we did the manual bleeding today, I was not seeing any air bubbles coming out, but the pedal remains just as soft. It's really weird. The pedal seems relatively firm with the engine off, but then it gets super soft after I start the engine. I followed the procedure from the FSM. (disconnected battery ground cable, went in order RR, LF, LR, RF). I have already gone though at least 6 bottles of brake fluid. I'm starting to wonder if the brake fluid I bought is somehow not compatible. I bought Prestone Synthetic Dot 3 for all Ford vehicles. I bought the one the says for Ford vehicles because it is supposed to have a higher boiling point and I'm sure I've seen people recommending that. Should I try a different brake fluid? Any other ideas?

 

that fluid should be fine, i've had the same problem when my mech changed my rear calipers. Pedal just went right to floor. Getting sick of this, i went to a different shop, where i had them install SS braided brake lines all over, and do a proper 2-man/4 corner bleeding. It's been great ever since! My mech said that bleeing has to be done multiple times with a intervals. He said the ABS system has long *** tubes/lines that store air @ any certain point, but under braking, the air eventually travels to the calipers, and that's when it needs to be bled. So, i'd reccomend proper two-man bleeding, followed by some driving (with lotsa brake use). Then rinse & repeat. GOOD LUCK!! (If this doesn't work, then the master cylinder is funky)

 

During the bleeding did you push the brake pedal all the way to the floor? The master cyclinder seal may have been damaged.

 

I bled my brakes several times and got the same problem, of having it spongy afterwards. I drove it around for a week and now it feels like normal again... hopefully this is not an issue because im not gonna mess with it again hahaha.

 

The only difference with the Ford fluid is going to be the HD fluid found at the Dealer, I believe. Any regular brake fluid you find will follow normal DOT 3 specs. Check the bottle, it'll tell you.

 

Thanks for the suggestions. I will continue doing 2 man bleeding every few days then with intervals of aggressive braking and hopefully normal pedal pressure will return. As far as the master cylinder goes, I'm pretty sure it's fine. The feel of the pedal is soft but constant (what you'd expect from air in the lines), rather than a bad master cylinder in which I would expect to feel pedal pressure being lost when holding the pedal down.

 

you might have a leak somewhere

 

+1 for dblair comments

 

I have the same problem, i just ordered SS brake lines, once i put them on i will see how it works.

From what i've read i think it might be your brake lines.