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Has anyone had issues with a recurring spongey pedal?

My car feels like it weighs 6000 lbs when pressing the brake pedal. The pedal felt spongey back in December so I bled the brakes using the 2 person method and about 24oz of motorcraft dot 3. Tons of air came out of the front lines, and none out the back. The fluid also looked like Iced tea. The pedal felt firmer after bleeding, but now 5 months later, the issue has returned, and the pedal feels worse than ever before. I have no brake feel and the car feels like it doesn't want to stop. The front brakes were done about 8k miles ago and the rears were done about 4500 miles ago. Plenty of pad at all 4 corners.

We never let the master cylinder run dry, I haven't seen any external leaks in the system, and I've pretty much narrowed it down to either garbage pads and rotors, or ballooning rubber lines. The car only has 38k miles on it so I was thinking that the lines could have dried out or weakened from sitting over time. The front rotors show some scoring and I have a slight steering wheel vibration under braking.

Has anyone had a similar experience? Any pad and rotor recommendations? Thanks.
 

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I have not directly experienced that problem; but air in the lines and/or the soft rubber lines would be my first guesses. If you swap the lines out for stainless lines, that would eliminate the expansion of the lines and leaks in the rubber lines as possible causes.
 

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Rotors: Centric Cryo treated
Pads: for daily driver, Hawk (5.0 or HPS); for track Carbo-tech

I would switch to stainless lines, though it could be a bad brake cylinder... worth looking.
 

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You may have had air get into the ABS unit where conventional bleeding procedures won't chase it out. The dealership and any good brake shop should have the equipment necessary to cycle the ABS unit to get it out. Supposedly if you go through a sequence of bleeding and then driving with braking that activates the ABS followed by re-bleeding . . . and run that sequence a couple of times, you may be good.

I doubt that the lines or the rotors are at fault (nor should OE or any of the better performance-oriented streetable pads, for that matter), though a faulty master cylinder would at least be a possibility.


Norm
 
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