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Just helped a friend do his front pads. We'd done the rears a few months ago. All was fine after.
After doing the fronts, the pedal was spongy - more travel than it had. pumping raised it some but not back to previous level. (a bit subjective of course).
OK, decided it was a good time to flush the old fluid and I did so - bleeding in the correct sequence w/ a vacuum bleeder. No change.
Several times after pad changes, caliper replacements, & bleeding I've ended up w/ a softer pedal. I've on occasion changed the master cyl - sometimes w/ a better pedal, sometimes not.
In the archives there several threads about this. Art B comments that he's had it happen after a caliper rebuild. Also see the below re boots sticking.
My method for removing old pads is to move the pads back with WP pliers (C-clamp & prying if they're extra sticky), clean up, slide in the new pads.
I'm wondering if something in the old-pad compression process changes the pedal travel. Wear in the old calipers? Master cylinder?
On one car I replaced all 4 calipers, pads, master cyl - and bled w/ vac bleeder, then drip, then a helper - and the pedal never regained it's old stature.
Since it doesn't always happen and is not limited to certain years, I;m nit sure what's going on. Possibly 2 things; 1) Pushing caliper pistons back changes pedal-travel characteristics; 2) There is some special factory trick to bleeding and/ or new/ rebuilt calipers have some design flaws.
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posted by Trev29 on Mon Nov 29 00:47 EST 2010 "Your dust boots may be stuck between the pistons and brake pad. This causes the pedal to go spongy as the rubber has to get compressed first before the pads start to grip.
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240s: 2 drivers and some parts cars
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