[rukp]

Hi All,

Anyone able to suggest why I'm getting uneven wear on the rear pads both rear wheel pads wearing the same - the outer pad is near enough worn to metal, caused a need to replace rotors on the OSF. Replaced both rotors and pads.

The inside pad on the piston is much less warn than the outer pad on both sides, pads were due for service in about 10k miles but due to metal to metal contact did it today.

No other brake issues - fluid changed on time, no leak in piston or around calliper, guide pins look good and not scored..

Thanks
Rukp

[Billfitz]

The usual cause for that is inadequate greasing of the caliper, pad and carrier mating surfaces. The result is rust, which prevents the caliper and pads from properly floating. I visually inspect and re-lubricate my brakes yearly. You can't rely on the sensors to tell you if pads need replacing, as there are eight pads but only two sensors. The iDrive guesstimate to the next required brake service is useless, it has no way to gauge pad wear.

[rukp]

Thks Billfitz, I had a little build up of brake dust but no rust, I had greased up as per the Bentley and online guides where pads meet the housing.

Will keep an eye on them. I agree the sensors are a bit of a nonsense and only a guide as they sit on one side only.

Thks

[e2p71828]

I have similar question too, but about front pads. I just replaced the front pads myself on my2013 F30 (and N20). It's got 98k miles and this is the first time the front pads are replaced. There is minimal rust and dust on the calipers where the pad "ears" fit.

The replaced pads are in general good shape with no rust, except uneven wear. The two inner pads, the ones on the piston side, were down to 3 mm on one side and 4 mm the other side. The outer pads are both at 6.5 mm.

I wonder if the uneven wear has to do with inadequate greasing of calipers too?

For the new pads, I applied the brake grease that comes with the new pads, on the pad "ears", as well as, for the inner pads, on the metal springs that go into the center hole of the caliper.

[Billfitz]

When you get more wear on one side or the other it means on the side that has more wear the pad is not retracting fully, but is remaining in contact with the rotor. Only lack of lubrication explains that.

[e2p71828]

Thank you, Billfitz, for such quick response!

How do you lubricate the calipers? Is it all the contact points and surfaces between the calipers and the pads? The pad "ears" and the 3-piece metal springs? I do not know the right terminology .

Now that I have done it once, replacing the pads, I think I can check for lubrication every year. Just want to know what to check and how to lubricate.

[Billfitz]

All metal to metal contact points. I use this: https://www.amazon.com/gp/product/B0...e?ie=UTF8&th=1

[e2p71828]

Thank you again, Billfitz!

[e2p71828]

Hello Billfitz, if you see this message, I asked a brake pad replacement related question in another thread https://f30.bimmerpost.com/forums/sh...2#post31616572. Appreciate much if you could take a look.