Those pesky brake sensors are buggers!!

My front pads were just about stuffed ('89 525i - approx 240k) so I bought a new set as well as a new sensor and spent Saturday arvo replacing the pads. I didn't have much trouble :D although the rotors had a huge lip on them and need replacing :( - trying to save for my wedding/honeymoon so I need the extra expense like a hole in the head. Anyway, the old sensor was connected to the outboard disk pad so I figured that the new one would go there also - wrong! with the thickness on the new pads, there wasn't enough room for the sensor as the backing plate of the pad was behind the caliper casting. The sensor must have been made of a bakelite type substance and promptly broke.

Which pad does the sensor go into? Has any other owners had the same problem? Would be grateful for a bit of advice as I should replace it soon (along with the rotors). The dash message "Brake linings" is still on - so I figure that it must be for the rear pads as the front one isn't connected and therefore can't be earthing out the circuit - so my theory goes!!

Andrew
White 1989 525i
absolutely stockers

just did mine. But changed all rotors and pads. The rear pads came with sensors built in (bremo, i THINK) but the front has separate sensors. Did not have the front sensor when they were installed. When I got the part, it plugs right in. Didn't have to take the wheel off. Your rotors might be lipped to the extent that it pinches on the sensor. Just my thoughts.

chia

Why exactly does anyone need brake sensors?

If any one has pride in their car (as all on this forum do, I'm sure) then they will a) always check on their pads periodically or b) have the car serviced by a competent mechanic.

To get rid of the brake warning light short out the sensor leads - it will get rid of the message and won't stop low brake fluid warnings etc.

issued when the circuit trough the two sensor wires is opened, grounding has nothing to do with it. If you leave the sensor out, it is just like to have the circuit opened.

Javier is correct - when I replaced the pads on my old E28 I didn't bother with the sensors as the feed wires were worn, so I connected the wires together to close the circuit - no warning light after that.

You don't really need it - you don't have a light on the dash to tell you what gear you are in ether.