ddombrowski

So I'm doing pads and rotors on a GLK350, and took the front wheel off to find the caliper carrier bolts to be some sort of external torx. I have an etorx set, but it only goes up to E16 and that wasn't large enough.

So, I figured I would order a larger set of Etorx but wanted to make absolutely certain it contained the right size. I've been trying to look up the size of the etorx on the caliper but I've been running into conflicting info.

In this thread the poster said he used some universal spline tool, but says 'splined' and 'hex' in the same sentence, which are not at all the same.

https://mbworld.org/forums/glk-class...placement.html
In this thread (W204), after a ridiculous amount of arguing, I still can't tell if its a splined tool or not to take the caliper carriers off.

https://mbworld.org/forums/c-class-w...bolt-tool.html

A few other threads suggest that the splined head bolts are NOT what you remove to remove the caliper carrier. Is this true? Did I miss something?

I suppose the best thing to do is pull the wheel off and check again but I was pretty sure it was an etorx bolt that was holding the caliper carrier on.

For reference, I am NOT talking about the hex head bolts that may or may not hold the actual caliper in. I know what those are. Nor am I talking about the rotor set screw (typically allen or torx) that hold the rotor in place during assembly. I'm talking about the caliper carrier bolts, the largest ones.

ble2716

If you're talking about the bolt behind the caliper, to remove it.
Then it is etorx.
I believe the size is 14mm (it been awhile, so don't quote me on that).

ddombrowski

I'm talking about the bolt behind the caliper carrier. It holds that bracket that goes around the brake disc that the caliper mounts to. If its etorx, its bigger than 16, because 16 is as high as my set goes and it was bigger than that.

ble2716

I've just checked the 4 bolts that came with the Zimmerman rotors and it is a regular 15mm bolts.
My GLK is a 2010 model.

vanrooster70

I had the same issue. I found a regular socket that fit very snug over those bolts. I'm not sure if it was metric or std size. I got them off no problem at all. No stripping or rounding off. I know it wasn't the smartest thing to do but I had a few beers and really wanted to finish the job lol. I'd go out and double check the size I used but it's 35 below here. As long as there is no play between the socket and bolt head, you should be good to go. Those carrier bolts are very high tensile strength for obvious safety reasons, I doubt you'd even be able to find round one off if you tried. Anyway.... agree or not, just wanted to let you know it was possible and easily done. Let me know if you tackle it, I'm curious now.... Good luck either way.
Mike

vanrooster70

Also, to answer your earlier question about what bolts to remove. there's no way to get the carrier off without removing those large etorx bolts. Not that I could figure out anyway. I just think people just didn't understand what you were asking. I just did mine and I can still see it in my head lol

ble2716

Okay, so I managed snap a picture of my GLK's front caliper.

I think the two bolts you want to remove are the ones in blue arrows.
Those are Etorx bolts and I manage to fit a regular 14mm socket over it.
The one in red arrow is 15mm bolt, which also comes with Zimmerman rotors when I ordered them.

bop11

Suggest not to use a regular socket. They are in with a lot of ft-lbs and you can round them off with a regular socket. Once you take the small ribs off, they are impossible to get out. You can't get a vise grip in there.
Buy the proper tool, they are ~$30 a set at Sears or Home Depot or $10 a set at Harbor Freight. You will probably need a long breaker bar so get that at Harbor Freight while you are there. 3/8" drive 17" long $9.00. Make the job easy. You will also need a heavy (4 lb) hammer to get the disk off if it has been on a while. Spray the center hub with WD-40 and then bang away. It will come off. Since you can't rotate the wheel, if it is an AWD, ( unless you jack both fronts off the ground) you need to hit the disk on outside and inside where the inner shield is not located to rock the disk. Use some anti-seize on installation of the new disk.

ddombrowski

A big thank you to everyone who responded. I picked up the spline tool from harbor freight and knocked this job out yesterday. The spline tool isn't the actual type of bolt head, but it worked better than a socket would have. Even so, there was a bit of galling on the head edges, so the load wasn't distributed evenly. The proper etorx socket is the best bet, but I still don't know what size it is. The largest Etorx I found at HF was 18, so I went with the spline set instead.



Oh my no, impact gun made quick work of these. I find it difficult to get a breaker bar in when doing brakes because they generally have a of play in the head area and with a long one I don't have a whole lot of clearance.

As for getting the disk off, yeah, it was stuck decent but not the worst I've dealt with. I like to use a piece of wood to knock the rotor off as I don't like to damage the old one ever since the time I wailed on a rotor to get it off, opened the new one and found it wasn't the right one and had to take it back to the store.

A little wire brush on the hub to clean it up, some grease, put it all back together and its good to go. I used the cheapo wearever brake rotors from Advance auto as a test, and so far they seem to be doing well. I'll do a little writeup on the whole job a little later since I don't think I've seen a full one with photos yet.

bop11

Nice job and write up. I went with the Centric disks because they are coated on the center and look nicer after the other types rust up. Have you done the rear rotors? If so, did you have to release the emergency brake shoes or did the rotor come off with no problem? I have used both Akebono and Centric ceramics and love that the wheels stay clean.

ddombrowski

I did not do the rear rotors, just the rear pads. Rear rotors were not nearly as worn. In my previous experience I've just pulled the rotors off. Sometimes they've had to be convinced to come off, usually a little pulling or light hammer taps help it along.

I used akebono on the rears as well.

mjhawkins2346

Do you guys put Copper Anti-Seize Lubricant on the hub or the back of the rotor when re-installing the rotor? I have used it in the past to make sure I don't have to hammer rotors off and want to make sure there isn't a taboo from Mercedes or someone about using it.
Sure makes life easier.

bop11

Don't know about Coppers but use Permatex anti seize on the wheel center. Makes it easier next time. Just go lightly.

ble2716

For those still wondering which is the exact socket size for the e-torx bolts.
It is E-18.