My '79 300TD recently started seeing the "low brake pads" light. It
started happening right after I had it in the shop because of some
suspension problems I was having (broken sway bar mount). The light
"pulses" while I'm braking, and sometimes is on while the brake pedal is
not depressed and sometimes it is off. The pulsing is related to the
speed of the vehicle.
I know for a fact that the back pads are huge, they looked almost-new
when I had the back wheels off recently. I haven't actually inspected
the front pads yet but I suspect it's related to the work done at the
shop (they were sloppy in a number of areas, and the fact that it
appeared literally the day I got the car back makes me suspicious).
So, I'm curious. How do these sensors work? Are they adjustable, or do
they just bolt in and that's that? Does this lamp on the dash mean
anything besides "need new pads?" (I.e. I don't know what light would
illuminate if my brake fluid were low, which it isn't.)
If I do need new pads, do people recommend any particular brands? The
sensor light pulses, which makes me think the rotors may not be true,
but I don't notice anything when I'm driving (as opposed to any American
car I've ever had in which the rotors would noticably warp within about
a thousand miles of being replaced). Oh, when I do the pads, should I
replace the sensors too? I see Autohaus sells the sensors individually
for like $1.50 which implies they're pretty highly disposable.
thanks a lot, I appreciate the help everyone's given me here.