Front Brake Caliper Bolts - 10mm HEX/Allen or Torx T55

[Katkarot]

Help guys,
On many DIY for 135i and E90 front brake pad change, they said to use 10MM HEX/Allen key to remove the caliper bolt.

When I tried 10mm HEX key, it doesn't go in. But I got a T55 and it fits and I also noticed the star indents too.

Any body got technical specs on the front Caliper bots? Is it 10mm HEX or Torx T55? I don't want to strip the bolt by using the wrong tool.

Thanks in advance

http://www.1addicts.com/forums/showthread.php?t=263962

[Katkarot]

Actually, our brakes look like this, should we remove the 2 bolts on the brake as mentioned here? http://f80.bimmerpost.com/forums/sho...1&postcount=16

and not the 2 T-55 bolts on the caliper itself?

[juld0zer]

The hex hole might have corrosion or contaminants in it. My 10mm fits fine but yes, you are NOT supposed to undo those allen bolts. They have loctite on the threads. It might seem like the quicker and easier route but when you first encounter the loctite you'll be cursing. Still not as bad as replacing discs on the rear though haha

Unmount the caliper via the 18mm bolts to the knuckle instead. Retorque to 110Nm.

[Katkarot]

Thanks! I found that answer tool in this thread as well.

http://www.1addicts.com/forums/showt...caliper&page=6

It is a T55 socket, even though 10mm Allen key somewhat fits

[Stewy_604]

Originally Posted by juld0zer

Unmount the caliper via the 18mm bolts to the knuckle instead.

^^^ This. There's no need to remove those 4 bolts (pins) noted in Step #3 on the front pad DIY. They are not made to come out and are Loctite'd in.

[juld0zer]

These are not the small pins which hold the pads. Those are replaceable but not required to be disturbed during a pad change.

The bolts in the image are the allen head bolts which point towards the hub, two per side, attaching the caliper to the bracket

[Havocsteve]

It does mention you can replace those bolts. When I did my pad change, I just added a little bit of red loctite when I cleaned the bolts up and put em back in. It's been well over 15,000 kms since my pad change and I've had 0 issues.

[Katkarot]

Originally Posted by juld0zer

These are not the small pins which hold the pads. Those are replaceable but not required to be disturbed during a pad change.

The bolts in the image are the allen head bolts which point towards the hub, two per side, attaching the caliper to the bracket

They are not Allen head bolts, they are T-55 bolts
You may be able to use 10mm allen key but sometimes not. But T-55 always fits.

I completed my pad change by unbolting the 2 18MM bolts on the side and took the entire caliper off. I did spray some lubricants on it prior nights.

All in all, the entire procedure was quiet easy.. but as usual, just takes time.