[MooMooM2]

Since I will be tracking the m2 comp I know I will need to do brake pads rather soon, still on stock pads and going to kill them before going to something else. Will go ferrodo DS2500 next because I am a noob and they will most likely be enough for me for a bit.

I want to do this myself and been looking at how to do it.

There is always the excellent video from Farkle! but also ran into this video

They differ a bit as in this video they just remove the 2 bolts and take the caliper out and change the pads but on the Farkle video he removes the whole caliper from the knuckle because there is no posted torque value for the caliper bolts.

So how are you all doing this? It would be much easier to just remove the caliper bolts but if that is not how it is suppose to be done the other way is not much harder. Also was reading about having to replace bolts, not sure if they were talking about the caliper bolts.

[ROBM2C]

Farkle is great to have in this community.

[Ratcher]

He removes the wrong screw though, there are 2 screws at the back of the caliper which are meant to be used/removed and replaced when you do put it back.

You wont find the correct torque to tight these long screws as per the video, the 2 screws I mentioned are 110 Nm.

Edit: you got it right here man:

Originally Posted by MooMooM2

They differ a bit as in this video they just remove the 2 bolts and take the caliper out and change the pads but on the Farkle video he removes the whole caliper from the knuckle because there is no posted torque value for the caliper bolts.

[FaRKle!]

BMW also explicitly states not to remove the bolts holding the caliper to the bracket in their documentation (same for M3/4 CCB caliper, and X5M). Although if the caliper bracket has an integrated stud and there's a nut holding the caliper to it (M5) they have a spec for that.

[MooMooM2]

That settles it then, specially if they specifically say to not remove those (I wonder why the reason is but better to just follow as removing the ones in the back is not much harder).

And the bolts should be replace right? Does anyone have a part number for those? (there was a thread recently with it I am pretty sure but I cannot find it for the life of me).

Thank so much @Ratcher and @FaRKle!

[FaRKle!]

BMW recommends replacement, but if you look at the thread size (M12x1.5), bolt class (10.9), and torque spec (110Nm) it's not stretching the bolt to the yield point and is just in the normal fastening torque range, so I don't personally think replacement is necessary.

PN for the torx version of the bolt is 34106864424.

[MooMooM2]

Originally Posted by FaRKle!

BMW recommends replacement, but if you look at the thread size (M12x1.5), bolt class (10.9), and torque spec (110Nm) it's not stretching the bolt to the yield point and is just in the normal fastening torque range, so I don't personally think replacement is necessary.

PN for the torx version of the bolt is 34106864424.

thank you!

So maybe the case of replacement for safety every few times or obviously if the bolt looks damaged.

[///MPhatic]

Originally Posted by FaRKle!

BMW recommends replacement, but if you look at the thread size (M12x1.5), bolt class (10.9), and torque spec (110Nm) it's not stretching the bolt to the yield point and is just in the normal fastening torque range, so I don't personally think replacement is necessary.

PN for the torx version of the bolt is 34106864424.

Maybe it has to do with heat. Heat does strange things to bolts over time.

[NathObeaN]

Crap. Just saw this. I've changed my pads numerous times by removing the 2 larger bolts. Never thought anything of it. Any advice? Should I replace the bolts? Is there a known torque for these bolts?

[agent_orange]

When deciding which bolts to remove, I checked the OEM procedure in ISTA+.
First under F87 type codes, which only had the blue brakes and these are lug mount without a bracket.
So then went to F80 looking for the CCB option, and while there was a heap of interesting reading about the rotors and how to check and weight them, allowable damage limits etc., the actual caliper procedure looked to be copy-paste from the blue brakes still, complete with incorrect 4 piston calipers in the illustrations.
Finally tried the F10 M5 type codes (same caliper), and that had correct caliper illustrations, and clearly said to remove the radial caliper to bracket bolts.
But in retrospect this was flawed, as the F10 M5 has integral radial mounts on the hub carrier, so no option to remove the axial bracket to carrier bolts because there aren't any.

Still, I will continue to remove mine from the radial bolts, but will preventively heli-coil or timesert the threaded holes in the bracket next time. (the bracket to carrier bolts go into a threaded steel insert already, which kinda suggests that is where we should be unbolting them)

[Ratcher]

Originally Posted by NathObeaN

Crap. Just saw this. I've changed my pads numerous times by removing the 2 larger bolts. Never thought anything of it. Any advice? Should I replace the bolts? Is there a known torque for these bolts?

For the bolts you used I used 90Nm when I changed those. This is the torque recommended by Porsche... didn't know what else to do.

It's still holding after many trackdays and around 25.000 km

[NathObeaN]

Originally Posted by Ratcher

For the bolts you used I used 90Nm when I changed those. This is the torque recommended by Porsche... didn't know what else to do.

It's still holding after many trackdays and around 25.000 km

Thanks although I'm now worried these are some kind of stretch bolt that may need replacing.

[Ratcher]

Originally Posted by NathObeaN

Thanks although I'm now worried these are some kind of stretch bolt that may need replacing.

Yeah, I was worried, too. Until I forgot about it... and see, now I've done a bunch of trackdays and no worries

[NathObeaN]

Originally Posted by Ratcher

Yeah, I was worried, too. Until I forgot about it... and see, now I've done a bunch of trackdays and no worries

Out of interest, where are people finding the recommended torque settings for certain bolts? Is there some kind of documentation for this?

[Ratcher]

Originally Posted by NathObeaN

Out of interest, where are people finding the recommended torque settings for certain bolts? Is there some kind of documentation for this?

Yes, there was a TIS, which I now think is paid. However I found all this information here in the F80 section and saved everything as screenshots so I don't forget

[NathObeaN]

Originally Posted by FaRKle!

BMW also explicitly states not to remove the bolts holding the caliper to the bracket in their documentation (same for M3/4 CCB caliper, and X5M). Although if the caliper bracket has an integrated stud and there's a nut holding the caliper to it (M5) they have a spec for that.

Can you provide a link/evidence for this? I'm curious what BMW say. Thanks

[Ratcher]

Originally Posted by NathObeaN

Can you provide a link/evidence for this? I'm curious what BMW say. Thanks

BTW check this one thread out:

https://f80.bimmerpost.com/forums/sh....php?t=1272952

The CCB from the F80 has the same specs as the 2NH from the F87

[MooMooM2]

and with all this I kind of wished we would have got the blue brakes instead of the BBK. Not that I am there but changing pads at the track if necessary on the BBK would be such a pain in the ass

[///MPhatic]

Originally Posted by MooMooM2

and with all this I kind of wished we would have got the blue brakes instead of the BBK. Not that I am there but changing pads at the track if necessary on the BBK would be such a pain in the ass

I wish they would have been an option, but then again, hard to call the car the "competition" and make what BMW views as competition brakes, and option.

[Ratcher]

Originally Posted by MooMooM2

and with all this I kind of wished we would have got the blue brakes instead of the BBK. Not that I am there but changing pads at the track if necessary on the BBK would be such a pain in the ass

No need for that. Just use good track pads, they will work for daily use too. I am extremely happy with my Endless ME22! No noise or whatever.

The closed calipers are indeed a PIA, but better for brake performance (see Porsche and co, same construction).

Originally Posted by ///MPhatic

I wish they would have been an option, but then again, hard to call the car the "competition" and make what BMW views as competition brakes, and option.

The 2NH brakes were an option on most markets

[///MPhatic]

Originally Posted by Ratcher

The 2NH brakes were an option on most markets

Yup, as were the 437M vs the 788M. Too bad they didn't give us those options here.

[Mavus]

very good discussion!

go to 8:30 … he says the two knuckle bolts should be replaced because of the locking washers