I have rebuilt calipers on the 123 cars with great success. Because I'm the tight fisted, anally retentive person that I am, I would rebuild them rather than replace them every time, unless I found the bore or piston had a problem which would preclude rebuilding. It's really not that much trouble. If I were doing it professionally with the labor costs to consider, rather than only parts costs, that would be a different matter.
And yes, if the system was never flushed and bled, that's probably what killed them. The fluid absorbs moisture, and then the moisture does them in. When I'm evaluating a used car, it's always impressive to see that the brake fluid has been flushed regularly.
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
[This message has been edited by LarryBible (edited 08-04-2000).]