Does anybody know if a 560 caliper will bolt onto a 123?
 

The 560 calipers I see are floating caliper like they were on my 500sec. I doubt they will work but I thought it wouldn't hurt to ask. It seems possible.

I am aware that the rotors on the two models are different sizes. The rotors on the 500 were the same diameter as on my 123s.

Tom W

All of the W126 calipers from 1986 are fixed 2 piston variety.

Yes, they will fit a W123, you will need 15" or larger wheels & either eliminate the backing plates OR use the ones from the later W126.

Oh, thanks.

I don't want to go to 15" wheels on my street car but I might on the autocrosser sometime. Do I have to use the larger diameter disc too?

Tom W

Yes.

IF you want very good brakes that don't require the 15's then use the 1984-85 brakes from a 500SEL or 380SE.

I don't know if it helps any, but the early model 300SD cars have a fixed two piston setup mounted under 14" wheels.

I'm not sure how they compare with the brakes on a 560, but I noticed the difference between the systems when I first pulled a wheel off of my 500SEC to check the brakes out.

If you want, I can measure them for you.