Rear brake warning came on on my R56 base and I have the red brake light.

The rear pads are at 6mm. I measured from the outside pads with my steele tool (super handy), but realize that the sensor is on the inboard pad and will measure that as well.

Does anyone know at what mm left on the pad, the two sensors are triggered? Anyone have a new sensor sitting around that they could measure the two stages?

I'm pretty sure that I haven't gotten the red brake light in the past at 6mm.

Thanks!

 

I would be interested in this answer as well.

 

Really, all it would take is for someone who has a new uninstalled sensor to d a couple measurements.

 

Do cars for north America have different brake pad sensors than in Europe?

My (european, LCI) Mini just has a simple sensor (i.e. either on or off). The yellow light comes on when the car has reached the projected (i.e. calculated) mileage since the last counter reset, irrespective of pad status (as there is nothing besides the break pad sensor that could monitor pad wear). When the break pad sensor "fires", the red light comes on (whether or not the yellow one was on previously).

When I last changed the rear break pads, I had already driven about 600 miles since the red light had come on and the pads had about 3 mm or more left. The new ones (Brembo) had 17mm.

Edit: the 600 miles I did between the red light coming on and installing new pads were pretty much all driven in inner city traffic.

 

Hello - about the same here, inner pad was 3mm, outer was 5mm (rear). On the other side they were both 3mm. Fronts were OK. Pads are cheap and easy to replace so I now just do so every 20 - 30,000 miles of mixed driving. The sensors are quite brittle and I usually order one on a free return basis in case I need it (we are a long way from any parts store).

 

I checked the inboard rear right brake pad and, like what giorgos posted here, it had about 3mm left, if that (couldn't properly measure without removing it).

The two outboard rear pads have 6mm left, so the sensor was doing it's job.

I can't believe that the pad with the sensor is designed to wear more. If it were a sticky caliper piston, why would the outboard pad on the other side be 6mm?

 

It is normal for the inner pads to wear faster. However, 3mm vs. 6mm sounds like a large difference, I don't recall it being that much.