Brake caliper bolt torque specs

[OppositeLock]

Would anyone happen to know the torque specs on the caliper bolts? I need to remove the calipers to swap in some new rotors. These are the E14 bolts holding calipers to the uprights.

Edit:
The bolts are part number 8891014034, in case someone is looking in the future.

 

[virtualmacho]

86 Nm both front and rear.

Front:


Rear:

 

[OppositeLock]

Remove and discard? Are these Torque-To-Yield bolts?

 

[virtualmacho]

Remove and discard? Are these Torque-To-Yield bolts?

Sure looks so...

 

[OppositeLock]

It's a little confusing, because TTY bolts are usually torqued first, then rotated a specified amount afterwards, like half a turn or whatever.

In a couple of other cars I've owned, the manual calls for bolt replacement because new bolts come with thread locker on them, and it's done that way to make sure the service bay techs don't forget.

I guess I'll buy a set of bolts and see if they're covered in thread locker. If they are, they're not TTY and I'll know for the future, but with brakes, better be safe than sorry.

 

[OppositeLock]

I took out the bolts today and re-used them, and they're nearly impossible to remove without some kind of damage to the head due to all the solidified thread locker on them. I had a battle with one wheel, and had to use a blow torch to warm up the iron upright to make it expand, then it came out ok. In the other wheels, I heated preemptively and the bolts came out very easily.

I put some blue loctite back on, and torqued to 86N-m, but torques are usually expressed for dry bolts, not lubricated ones, so I could have overtorqued, but hopefully not too badly.

Those bolts still need to be changed out, since I tortured a couple of them, so I'll do that next weekend before the track.

 

[OppositeLock]

These bolts, surprisingly, are a special order item from dealers, $18 to $35 each based on calling the three dealers within driving distance of me. Crazy! I tried to find an alternative, but I could not.

The bolt is a 10.9 grade, 12mm bolt, 1.5mm thread pitch, 75mm long. A standard hex head won't work because of clearance issues, so you need an Allen socket, or the Torx head we've got, or something else with a small head. I checked a bunch of bolt supply places, even McMaster, and didn't find an alternative. For comparison, a 10.9 bolt that's 80mm (which wouldn't fit in front, but would fit in the rear brakes) is about $3.