Help: New Shoes..Can't Get Drums Back On

[vande17941]

Bought a relined set of shoes  from Buds because original lining seperated from original shoe. Car has 55,000 original miles on it. I machined the drums a tiny bit just to make sure they are round.

The shoe thickness as received is 10.7mm including the backing plate.

I did the following.
1. Loosened parking brake cable completely.
2. Loosened cam adjusters completely.
3. Opened bleeder valve on cylinder.

I can get the drum on about 1/3 of the way in and that's it!  Am I missing something? Or is it the fact that Buds made the shoes too thick? Would .7 millimeters make that big of a difference?

Ideas?

[WRe]

Hi,
the brake pads are 5 - 6 mm without plate .
Did you check the excenter spring, sometimes it's blocked and the cam does not move back?
...WRe

[vande17941]

The cams moved great and the shoes moved right in...still can't get the drum on. Need to know if a total thickness of 10.7 millimeters including the backing shoe is too much to get the drum on

[WRe]

Hi,
if you look at the attached pictures from SLS I would assume that the pads (6mm) are double of the backplate which means that both together is less than10mm. This thread says 10mm in total:  www.sl113.org/forums/index.php?topic=12474.msg89714#msg89714.
...WRe

[vande17941]

These are NOT parking brakes. They are shoes from a 230sl. I'm guessing 10mm max, also.

But a guess isn't an answer. Hoping someone knows.

[mmizesko]

Fats Waller would say " Yo Feats too big"

Sorry, Had to do it.

Mike

[vande17941]

HA HA! I'm assuming, based on the thread references earlier, that the Benz Dr's answer of 10mm is correct.....he is ALWAYS correct.

So, the fact that he shoes I have are almost a full mm too thick, explains my bloody knuckles, cursing, and screaming.

[WRe]

Hi,
I thought we speak about drum brakes of your 230SL, why now parking brakes?
...WRe

[Tomnistuff]

I ran into this same problem on my 230SL rear brakes.  I had the shoes relined and even sent them the dimensioned drawing on page 42-22/1 of the BBB.  They still came back too thick.  I couldn't find a thickness which included the shoe flange, because it is not constant.  It is tapered thicker as it gets closer to the center rib.  Since it's cast, I assume that that taper is the draft angle of the casting.  The lining is supposed to be 6 mm thick.  Mine was about 7 mm and I had no choice but to spend several days block sanding the lining while repeatedly fitting the hub.  Fortunately, every place where the hub was tight, it left a darker polished spot on the freshly sanded lining.  After about three days of sanding, fitting and hand spinning the hub, I got it to fit and spin without leaving any marks on the lining.

My wife is right, as usual.  Restoring a 50 year old car (even a Mercedes) is the work of a cloistered monk, the kind of person who copied and illustrated Bibles by hand a few hundred years ago.

Take a look at BBB page 42-22/1, "Replacement and Resurfacing of Brake Linings".

Tom Kizer

[ja17]

You might want to try loosening the emergency brake adjuster to allow the shoes to retract further. On a 230SL, unlike the 250s and 280s, The main rear shoes are also the parking brake shoes.

[Shvegel]

If you are positive that the shoes are fully retracted find a shop that rebuilds truck clutches or the oldest crustiest auto parts store(or even the oldest crustiest mechanic) you know and see if they "arc" brake shoes.  a lot of auto parts stores in the olden time days used to actually rebuild their own brake shoes by riveting new linings in then they would grind down the asbestos shoe to the proper size on an arcing grinder.  Good times!  The good news is your drums still have enough material on them to make this an issue. 

PS: You will notice I have substituted the phrase "In the olden time days" for the more current phrase "Back in the day."  When I taught mechanics for BMW's S.T.E.P. program invariably one of my sub 20 year old charges would use the phrase "Back in the day."  My response "Back in the day is anything that happened 25 years ago or more.  You guys have no back in the day."

[450sl]

I have used a Lathe to work on brakeshoes of all sorts.