I am doing a brake job on my boss's wife's 97 S500 and forgot which pads on the front gets the wear sensor. This car is different from my W126's in that there is only one sensor per side, which pad gets it, the inboard or outboard??

Another strange thing, only one rear caliper gets a sensor and harness, the left rear. Which pad on it gets the sensor?

(I have all OEM parts if it means anything)

Thanks,

Chas

Inboard.

Thanks my friend,

I am getting it back together but the wife busted me working on it early this a.m. when I am supposed to be finishing the tilework in her kitchen. I am actually trying to get it done this weekend so I can go cruisin' a bit, test drive it good, ya know! Gotta take good care of it for someday it may be mine. I inherited my first Benz, a 380 SEL from her (boss's wife) some years ago but with a jumped timing chain and a bad tranny.

I guess the inner pads are supposed to wear out faster than the outers but see no reason why they eliminated some of the pad sensors on the W140's. Having only one on the rear doesn't make much sense either.

Chas

Tilework, yuck. I never enjoyed the messiness/gritty feel of the mortar and grout. Like you, I much prefer working on cars.

You have me questioning myself now. I mounted mine on the inboard but I don't think it should matter too much. As long as the calipers are floating as they should, wear should be almost equal. Once the sensor is actuated the brakes should be checked but there is usually enough leeway to allow for 1-3k more miles of driving.

Have fun with it.