I have a 95 318i. I just changed the brake pads and rotors, do I haver to replace the sensor? If I use the old one how do I reset so that the light goes off on the dash? I appreciate any advise...thanks.

If the light came on due to the pads being worn down to minimum then yes you have to change the sensor. The old sensor will always keep the light on. I believe when you install the new sensor you need to keep the ignition in the on position (2) but not started until the sensor light goes out to reset for the new sensor. gl

Yep, if the light turned on because of pad wear, you'll need a new sensor.

Turns out that when the pads are close to wear limit, the sensor rubs against the rotor. After it wears a bit, the two wires in the sensor contact the rotor and complete the circuit that turns on the light.

Thanks for the help, I have the sensors on order.

Only BMW would come up with this! Good way to save the rotor! My 83 728i has these on it and I was wondering the same thing, but my pads are not down and out yet. It has ABS too. Leave the sensors ON? thanks

They're cheap and easy to replace. If new sensors do not cause the light to go out, you should check the wires to assure they're not worn through. I think that if you just unplug the sensors, the light will go out.

It seems these are a typical replacement item, right? I'm guessing most shops replace them with the brake job? I do my own except for turning the rotors.

The sensors are about $10, but they're generally only replaced when the light comes on. There's one on the front wheel, I forget whether it's left or right, and one one the opposite rear wheel. They fit into a notch on the brake pad. At least that's how it is on my e39.

BTW, I didn't know they made a 728i. Is that a 6 cylinder?

My neighbor is military and bought it 83 in Germany then brought it back with him in 89 to the states. Decent car, but has sat for a few years.