So I've been having a small issue since I've had the car that the top inch or so of brake pedal travel is soft. You pump them, they get hard, then slowly sink an inch or so. The catch is, the car still slows and stops pretty reasonably even in that inch of mush. Knowing the car's history, I knew there was a good chance for an improper ABS bleed, or the possibility of a damaged master cylinder from dry bleed.
And so then I did an all around vacuum bleed, while also cycling the ABS with Forscan. Speaking of Forscan, if anyone has detailed instructions they can point me to (besides the on screen prompt of "push pedal" and "release"), that'd be great, unless it really is just press and release. I saw Fords bleed procedure, but for the ABS they just say refer to service manual... Bleeding did nothing, and I don't want a pressure bleeder, a pressurized tank and lines full of brake fluid scares me. Vacuum only. Also did pads and rotors, no better.
My next step was to experiment a little. Does the pedal change with the handbrake on? No. How about with the hose pinched? No. Now here's the interesting one. Does it change with the hill start activated? YES! Rock hard. Hill start uses ABS as a kind of line lock, closing off a valve prior to the air bubble, yes? Therefore the pedal feel? So here's what I'm asking after reading the backstory. Does anyone agree with me that because of the difference of pedal with the hill start activated, that the issue is NOT the master cylinder? I know it could still be the ABS module itself, but one thing at a time. I feel like knowing this, it'd be worth paying Ford to do a professional bleed job, knowing the money/time is not wasted. If anyone has methods of isolating components, that'd be appreciated too. Thanks.
And so then I did an all around vacuum bleed, while also cycling the ABS with Forscan. Speaking of Forscan, if anyone has detailed instructions they can point me to (besides the on screen prompt of "push pedal" and "release"), that'd be great, unless it really is just press and release. I saw Fords bleed procedure, but for the ABS they just say refer to service manual... Bleeding did nothing, and I don't want a pressure bleeder, a pressurized tank and lines full of brake fluid scares me. Vacuum only. Also did pads and rotors, no better.
My next step was to experiment a little. Does the pedal change with the handbrake on? No. How about with the hose pinched? No. Now here's the interesting one. Does it change with the hill start activated? YES! Rock hard. Hill start uses ABS as a kind of line lock, closing off a valve prior to the air bubble, yes? Therefore the pedal feel? So here's what I'm asking after reading the backstory. Does anyone agree with me that because of the difference of pedal with the hill start activated, that the issue is NOT the master cylinder? I know it could still be the ABS module itself, but one thing at a time. I feel like knowing this, it'd be worth paying Ford to do a professional bleed job, knowing the money/time is not wasted. If anyone has methods of isolating components, that'd be appreciated too. Thanks.