Parking Brake Shoe Replacement: Drum will not budge - PeachParts Mercedes-Benz Forum

azurite300E · #1 05-30-2008, 09:59 AM

I need to replace the parking brake shoes in my W124, and in order to remove the rear brake disc/drums I removed the caliper and then the single 5mm Allen holding screw as outlined in the instructions, but the disc/drum still does not come out. I read somewhere that this is a common problem and that one needs to hit the drum squarely with a 4-pound iron hammer (not a rubber mallet) in order to loosen them.

Has anybody ever tried this, or maybe had a different solution to the problem? I would rather try a less "violent" approach first, if one does exist.

Thanks.

david s poole · #2 05-30-2008, 10:27 AM

you will find that the centre has rusted on.hit with hammer until it breaks loose.then you may have to loosen up the cables at the main adjustment so the drum/rotor will come off.[sometimes there is a lip on the drum part and the shoes catch on it as you try to pull off].

azurite300E · #3 05-30-2008, 10:34 AM

Great, thanks for the info, but could you please be a bit more specific as to where one needs to hit the drum, or are there any areas to avoid. And how hard should I really hit it?

Thanks again.

pmckechnie · #4 05-30-2008, 04:56 PM

Hit it right where the lug bolts go in. Hit it hard. Hit it in several places around the hub. It will POP and then come right off.

Arthur Dalton · #5 05-30-2008, 05:57 PM

Quote:

Originally Posted by pmckechnie

Hit it right where the lug bolts go in. Hit it hard. Hit it in several places around the hub. It will POP and then come right off.

Correct...what you are doing is actually bouncing it off the hub..
Some BP Blaster helps

Martineau Gauda · #6 05-30-2008, 05:59 PM

I use an air hammer with a wide flat round - head punch, short bursts between the hub area and the screw holes after spray of pb plaster. I do this from the front of the rotor.

It came right off with the intense vibration. I clean the hub area up well with wire brush or 600 grit sandpaper to remove rust and put a very thin coating of high temp anti-sieze only on the rotor mating surface.

Good Luck

Martineau Gauda · #7 05-30-2008, 08:48 PM

It may be safer to leave one of the lug nuts in a little so that the rotor does not fall off abruptly and cause serious personal pain.

Hope this helps

azurite300E · #8 05-31-2008, 09:08 AM

Thanks for all the replies, I'll try to get the job done this weekend and report back.

Chadahar · #9 06-04-2008, 02:17 PM

I'm in the midst of doing the brakes on my 1989 560 SEC so this is interesting to me.
Just a thought, could you possibly have them in upside down (read rights on the left and lefts on the right or are then symmetrical?? My new ones are in the box and I haven't looked at them yet.

speace · #10 06-04-2008, 02:59 PM

Your first photo comparing the curvature of the shoes seems to indicate that they are not the same curvature, which would say you do not have the correct replacement shoes.

How does a new shoe fit the inside of the drum if you hold it in there with the parts off the car? The curvature should match...

azurite300E · #11 06-04-2008, 04:11 PM

Quote:

Originally Posted by speace

Your first photo comparing the curvature of the shoes seems to indicate that they are not the same curvature, which would say you do not have the correct replacement shoes.

How does a new shoe fit the inside of the drum if you hold it in there with the parts off the car? The curvature should match...

I've loosely fitted the two remaining shoes into the drum/disc that I'm working on now and the curvature seems to match pretty well. Please see pictures bellow.

On the other two shoes that have already been installed, the drum doesn't fit over them just by a small margin, but enough to make it impossible for the drum to fit even if one would try forcing it on. The total diameter of those two installed shoes is slightly larger then the inner diameter of the drum.

azurite300E · #12 06-04-2008, 05:27 PM

I think I found something, please look at the pictures bellow. These are the "end-pins" that go into the star-adjuster of both the new (left) and old (right) shoes. It is quite clear the pin on the new shoe is much longer, and this might be the reason why the drum will not fit over them once they have been installed.

The pin on the old shoe roughly measures about 9 mm, and the one on the new shoe measures 12.5 mm. In the third picture you can actually see how much needs to be cut off in order to match the old shoes.

BTW, the other ends of both old and new shoes match perfectly, that is where the slot that goes towards the "spreader" is located.

Please correct me if I'm wrong on this, but I'm seriously considering sawing the pins of the new shoes down to a size that will match the old shoe's length.

Any suggestions or ideas if I'm on to something here?

azurite300E · #13 06-04-2008, 03:55 PM

Quote:

Originally Posted by Chadahar

I'm in the midst of doing the brakes on my 1989 560 SEC so this is interesting to me.
Just a thought, could you possibly have them in upside down (read rights on the left and lefts on the right or are then symmetrical?? My new ones are in the box and I haven't looked at them yet.

Interesting point, but as far as I can tell, all four shoes are identical (aren't they?), so there should be no way to mix them up. If they have to be used in a specific way I'm guessing that they would be properly identified and packed, which they are not. All four look identical, and are packed together in the box.

No mention of any differences among the shoes in the service manual CD either.

Martineau Gauda · #14 06-04-2008, 08:55 PM

Is the bottom cable adjuster frozen, or is the cable adjustment the problem? Make sure the bottom of the shoes are seated correctly in the cable adjuster slots.

Just did my parking brakes on C280 and everything has to be centered correctly before the rotor can be put on. Looks from the picture that the bottom parking brake adjuster attached to the cable is not fully retracted. Also make sure the top of the shoes ears are fully seated in the adjuster.

Had problems with the bottom adjuster attached to the cable being completely frozen with rust. Lots of work cleaning and freeing the mechanism.

Hope the helps

Martineau Gauda · #15 06-04-2008, 09:12 PM

Also, on the bottom spring should it install and loop from on top instead of going under the shoes?
May not make a difference but I know the top spring has to be installed from the bottom and go under the star-adjuster.

I made note that the bottom spring was installed on top when I did my parking brakes.

If the bottom cable adjust is not free it will create the problem you are describing.