[bavarianride]

My outer rear pads still have 5mm(min.spec 3mm), while the inner pads have not been measured.

With cold weather the rear brakes start to squeal on cold start for the first few brake appliances. Once warmed up there is no squeal.

So is it fair to still wait for rear brake sensor to trip?

[Billfitz]

Measure the inner pads. Why? Read this:
http://f30.bimmerpost.com/forums/sho....php?t=1471617

The brake squeal may be normal, but there's only one way to know for sure.

[bavarianride]

Originally Posted by Billfitz

Measure the inner pads. Why? Read this:
http://f30.bimmerpost.com/forums/sho....php?t=1471617

The brake squeal may be normal, but there's only one way to know for sure.

Did you have consistent squeals(upon each brake application) when the inner pads wore down to 3mm?

My brake fluid change invoice from indy 4k miles ago did say inner + outer rears all read 5-6mm. And my squeal was on first + second light application upon cold start.

Also a forceful jam of the brake first thing in the morning seems to have no squeal.

[Billfitz]

I had no squeal or any other warning signs before the sensor tripped. That's probably due to the frozen pads. Squeal happens when the pads shift about, which they have to do to some extent to allow them and the caliper to float. A bit of squeal or even groaning after the car's been sitting over night isn't unusual. Squealing all the time is a problem.

[bavarianride]

Originally Posted by Billfitz

I had no squeal or any other warning signs before the sensor tripped. That's probably due to the frozen pads. Squeal happens when the pads shift about, which they have to do to some extent to allow them and the caliper to float. A bit of squeal or even groaning after the car's been sitting over night isn't unusual. Squealing all the time is a problem.

To be specific, F30(and E46/E39 in the past) has wear sensors at front left(driver) inner pad, and rear right(passenger) inner pad.

So the inner pads not covered(by sensors nor visual inspection) are front right inner and rear left inner.

So the sensors and visual can cover 6 out of 8 pads, correct?

[Billfitz]

The sensors cover two out of eight, visual covers eight out of eight. After my experience I won't trust either the iDrive or sensors to tell me what the condition of the pads is. Not a biggy, since I rotate my tires yearly anyway. I would have spotted the bad wear on mine had I bothered to do a proper check of the pads with every rotation, but I didn't, because the mileage was so low. Lesson learned.

[bavarianride]

Originally Posted by Billfitz

The sensors cover two out of eight, visual covers eight out of eight.

OK sensors + visual without wheel off is 6 of 8 then.

Yes routine wheel rotation and/or summer <> winter tire swap would be great time to inspect 8 of 8.

[chriscurra]

Mine did this, brakes still had lots of time on the pads. A - cheaper pads will squeek, but I was old that mine were ok and that initially the squeek but once warmed up the squeek is gone.