How do BMW brake sensors work??

[KISS_ME]

I was working on changing the front brake pads out today on the 3 series and notice there's a sensor on the inside pad. Looking at various BMW forums, I read some people changing the sensors out when they change the pads but some do not. Does anyone know if these sensors are a must change? Better yet does anyone have a technical idea of how these work so i can decide for myself?


Thanks in advance

[JustinMCS]

Yes they are a must change. Depending on year some are one stage and some are two stage. They are cheap enough so I just do it. One in the front and one in the rear.

Lots on the forums like e90post or e46fanatics

[KISS_ME]

Ok. Thanks. Time for Ebay

[natty54]

They work like any other brake sensor.

They are cheap enough just to change. If you dont want to then plug in the old sensor and then take the two wires coming out from them and link them together

[G-ZUS]

Originally posted by KISS_ME
I was working on changing the front brake pads out today on the 3 series and notice there's a sensor on the inside pad. Looking at various BMW forums, I read some people changing the sensors out when they change the pads but some do not. Does anyone know if these sensors are a must change? Better yet does anyone have a technical idea of how these work so i can decide for myself?


Thanks in advance

With those sensors, if you change the brakes before the light comes on - you can get away with only changing brakes. If the light comes on, you have to change the sensor too or just live with your light on the dash. The sensors are <$10 at rockauto.

[J.M.]

The sensors usually break when you try to remove them from the old brake pads. Just replace them as mentioned.

[mr2mike]

Originally posted by KISS_ME
Ok. Thanks. Time for Ebay

Originally posted by natty54
They work like any other brake sensor.

They are cheap enough just to change. If you dont want to then plug in the old sensor and then take the two wires coming out from them and link them together

Great advice Do it right the first time guys!


Sounds like you run regular gas in that thing too if you're skimping on a $10 item.