I have a '93 Grand Marquis LS with ABS and Traction Control.
Last week, the master cylinder and rear brake shoes were replaced when
my brake pedal started sinking to the floor (the BRAKE light never came
on - there was always enough brake fluid).
After this work was done, I started noticing that the car would
occasionally shudder while moving and the rear left wheel stank like
I went back to the mechanic and he replaced the caliper on that side
since it was locking up. (I started noticing an occasional shudder a
few months ago when driving in stop and go traffic and suspected this
was the problem but my previous mechanic said the brakes were fine and
my tranny was starting to go (I since moved and am trying out this new
Smell and shudder are now gone since the caliper replacement. But
here's my problem. Now I notice that the brake pedal feels a little
squishy under my foot and the car seems to need more force on the pedal
to make it stop. Also, the pedal will sometimes sink down a little
while the brakes are applied but never down to the floor like it did
right before the master cylinder was replaced.
Before I had any of this work done, the brakes were great. The pedal
was always firm and far from the floor. I rarely (but did sometimes)
noticed the pedal sink under my foot while appied.
My question is: what would cause this to happen? I asked the mechanic
since I first noticed it as I drove away from the shop and he said he
drove the car and everything is fine. Why would the brakes feel and act
differently than they did before?