Brake sensors

[OneM]

I bought some new pads (front & rears). BMW advised me that all the brake sensors have to be replaced following new pads installation.

Is this true?

[craina]

Yes it is true. The old sensors will not work with the new pads. Dumb.

My sensors are no longer connected, no issues. I just keep an eye on the pads. Obviously the car won't tell me when they are worn but I swap them regularly enough to see if they are worn too far.

[HP Autosport]

Originally Posted by OneM

I bought some new pads (front & rears). BMW advised me that all the brake sensors have to be replaced following new pads installation.

Is this true?

Yes, and no. If you can remove the sensors from your old pads without breaking them, you can use them again.

[OneM]

Thanks guys!

[jlc45]

I know this is an old thread but I have a question relating to sensors.
I removed and reinstalled the sensors on my 135i. They just slip out of the little notch in the pads. (I just removed the sensor end from the pads, I didn't remove the sensor wire from it's connector.) One was kinda loose, it looked like it may have been missing a small bit of plastic....(?) So I just used a bit of super glue to hold it in when I reinstalled. I have no indication of any problem. There's no warning lights or anything lit up on my dash. Here's my questions: What happens to activate these sensors when the pads become worn? What kind of a warning message happens? It looks to me like the pads would have to be very badly worn in order for the sensor to actually touch anything. Does a bad / malfunctioning sensor send a warning message? (I think this is a crazy example of over-engineering and unnecessary expense. I check my pads at least once a year and I never wear them out.) (I just changed the front pads on my Acura TL and they had 108,000 km on them and were about 60% gone.)

[CarJunkie]

They start to wear when the pad thickness lets them contact the rotor, looks to be about the last 3-4mm of pad material. As long as the sensor is intact, you won't get a warning. My front one won't stay in place with the PFC pads I am using, so I have it secured to the strut. Like craina, I see the pads often enough that I don't need the sensor. You will have a constant warning light if you don't have an intact sensor plugged in, though.