1972 280SEL 4.5 Brakes
 

Our vehicle is still in the original family and is in beautiful condition (gray with a dark red interior) but has sat indoors for several years and now needs the brake calipers rebuilt as they've stuck from lack of use. The brakes themselves are excellent with virtually no wear but all the rubber boots have deteriorated so apparently moisture had worked its way into the outer ends of the cylinder bores.

I am rebuilding them now but I noticed that the pads appeared to have been bonded to the retainers (?) using the orange high temperature silicone. Is this the way they are supposed to be or was it a kludge by the shop that always serviced it? Otherwise, what returns the pads after releasing the pedal? To date my experience has been only with drum brakes on vintage American cars (Packards. Cadillacs and Imperials) but I can't imagine gluing brakes together! Also, should the guide pins and flat spring hardware also be replaced and, if so, what is holding in the pins?

Can anyone advise on these things and possibly send some service manual pages with any reassembly specifics I might need? Right now I am doing only the fronts but will be doing the rears next and will probably turn the rotors while it's apart and, of course, I'll replace the flexible lines just to be safe - literally.

. . . In the meantime: does anyone know of a source for the small seals that go between the caliper halves? They apparently do not come with the rebuild kit and, as my pistons were stuck from lack of use, it was necessary to disassemble the halves to un-stick and properly clean the bores. They are like flattened o-rings about 9.5mm OD; 4.75mm ID and are about 1.5mm thick. That’s about 3/8” OD; 3/16” ID and 1/16” thick. Since my own have been crushed inside the calipers since 1971 or 1972, I imagine the thickness should be a bit more

Lots of work! You can buy rebuilt calipers for under $100. You should replace the hoses too. the brake fluid swells them shut. I think I got my fronts for $75 and the rears for $55 and they came all shiny like new.