[Mike-Bracknell]

OK so my offside outer rear brake pad was metal on metal for the last week, and since I knew the stealer prices would be astronomical I bought some pads and did the work myself.

The job wasn't too bad at all, consisting of:

- Jacking up the car
- Taking off the wheel
- Removing the caliper clip
- Undoing both caliper bolts (using an impact wrench given the lack of access in there)
- Sliding the caliper away from the disc
- Pulling off the pad sensor
- Removing both pads and retaining the pad sensor clip
- Squeezing the caliper open with a clamp
- Replacing with new pads
- Replacing the sensor clip
- Bolting the caliper to the hub
- Clipping the sensor to the pad
- Replacing the wheel
- Depressing the brake pedal several times until hard

Now, this led to 3 questions:

1) When I put the ignition on, the car reported a bulb had blown in the "exterior lighting system". Would this in any way be related to the work i'd done at all? I couldn't find any lights out at all when I looked, so am not sure where to start on that error

2) The offending metal-to-metal pad was the only one worn that badly. The inner pad on that side had maybe 2.5mm left, and the pads on the other side of the car had about 3mm both sides. Does this indicate a specific issue with the pad/caliper/etc? or is it a known issue with that pad due to the stability system? or what? (I was also a bit pissed off that the first I knew of the pad issue was the grumbling noise rather than a dash light).

3) On googling pad changing on an E90, several posts mentioned that you could reset the pad warning system so long as you replaced the sensor. I have no idea what this is on about since the only sensor came embedded in the pad itself I guess. Does this info only relate to the front pads then (which I am due to tackle on Saturday)? or am I missing a sensor that should be changed for the rear pads? And if i've changed the rear pads only, and have not seen ANY warning lights or anything related to pads on the dash, can I reset the mileage-based warning in the computer with no downside?


Cheers,
Mike.

[fastloop]

Normally you can get to the caliper bolts using a standard 7mm allen key socket, but I use a 2nd jack to lift the suspension strut a bit to get more access.

1. Unlikely. Could be a loose connetion, so find the offending bulb and have a look. I had to reseat a few of my brake light bulbs to get rid of an intermittent bulb out issue.

2. Could be the caliper not sliding properly causing the pad on one side to get more worn. But from memory min pad thickness is 3mm, so all your pads were below min spec. In regards to no warning then the computer can only give you a rough estimate and it doesn't mean that you shouldn't visually inspect the pads. Personally I would hate if the computer came up early and said my pads were worn when there was plenty meat in them.

3. The sensor is on the right rear and front left. The cable plugs in behind the wheel arch lining so you have to unclip this a bit to change the sensor plug. The sensor it self clips into one of the pads. So if you didn't unclip the inner wheel lining then it sounds like you didn't change the sensor.