Greetings, folks! I've been messing around with the well-known spongy brake pedal on my '04 MM for quite a while now. I've got SS brake lines, Russell Speed bleeders, bled all corners in every way possible several times, vacuum pump bled, etc., etc. I also brought it into the dealership to bleed the ABS pump, which was not successful for some reason (they said they were unable to fully engage the pump????). In the end, there is still too much pedal movement before the brakes engage. They're good when they engage, but the pedal moves too much before they engage. I've also done the activate-ABS-in-the-rain trick a few times, to no avail. The pedal doesn't drop when I put constant pressure on it, making me think it is not a problem with the master cylinder.
And so, I'm looking to upgrade the booster to an '03+ style. Based on what I've found on this site, there was an upgrade in '03 that provides much better feel. I have an '05 MGM, and can say with certainty that it has MUCH better brake pedal feel - the pedal is always hard, and the brakes bite very quickly every time. Both cars use the same brand rotors and pads, bedded identically, and the calipers have been thoroughly cleaned and lubricated. All the fluid is new Ford DOT 3 as well.
The question I have concerns what else is required for that booster upgrade. I have read a few threads that appear to indicate that a corresponding pedal assembly is also required when upgrading to the newer booster.
Can anyone confirm with certainty that an upgraded pedal assembly is required for this swap or not??
Obviously it would be much simpler to just swap the booster if possible, but any input at all would be greatly appreciated. Thanks in advance, and stay safe!