caliper piston

[jeffc280sl]

Here are a couple of pics of my caliper pistons.  The one on the left is unpolished.  The right one has been polished on a buffing wheel using 3M fine cut paint rubbing compound.  The polishing removed dirt and grime but did not bring back the chrome surface which was almost completely worn off in the caliper during useage.

Does anyone know have any experience with the various companies that rebuild calipers and do they replace the pistons?  Or do they clean and buff them as I have and reinstall with new seals?

Download Attachment: brake piston.jpg
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Jeff C.
1970 280SL 4-speed

[jeffc280sl]

Here is a pic of the dirty piston after buffing.  On the right side near the top you will see what is left of the chrome surface.  The rest of the chrome layer has been worn off during use.

Download Attachment: piston 2.jpg
28.5 KB

Jeff C.
1970 280SL 4-speed

[bpossel]

Hi Jeff,

Check this out.  A "set" of calipers for 160!
http://www.classicgarage.com/rearbrakcalf6.html
Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[jeffc280sl]

Thanks Bob,

I've purchased rebuilt calipers before and they work fine.  This time I thought I would take one apart and see how difficult they are to rebuild.

In looking closely at the calipers I discovered that the previous owner had different calipers on the rear axle.  Both are Ate and seem to fit and they take the same pads. The pistons on one side are much larger than the ones on the other side.  I doubt the mismatch was intended but it does bring up an interesting thought about larger pistons and improved performance.

Anyone have experience in this area that they care to offer
Jeff C.
1970 280SL 4-speed

[George Davis]

Jeff,

I rebuilt my rear calipers a few months ago.  The 113 rebuild kit didn't fit, and eventually a local MB parts guy figured out that the calipers are 250/8 sedan calipers.  Rather than hunt down 113 calipers, I just rebuilt and reinstalled them.  They bolt right up and seem to work fine, although the pipe appears to have been bent to connect properly.  I know the piston diameters were different, but can't recall now if the 250/8 pistons are larger or smaller than the 113 pistons.



George Davis
'69 280 SL Euro manual

[jeffc280sl]

Does anyone undertsand the part markings on Ate calipers?  The following came of the two 3.27 280SE 4.5 axles I'm refurbishing.


G 86 (large piston)
35 10
35 9
35 38R

Thank you.

Jeff C.
1970 280SL 4-speed