The driver's side rear brake caliper on my mum's 1990 740 has been dragging. I had a look at it this morning and found the outer piston like this:
The piston was seized solid or at least I couldn't budge it and the pad on that side was about 2mm thinner than the inner pad. Reckon it's worth trying to rebuild it or just replace it?
For comparison the inner side piston looks like this:
I checked the passenger side caliper and both pistons look similar to the second photo.
I'd prefer to replace the caliper given the state of the piston so I guess I'm answering my own question really 😃
But thought I'd seek the collective wisdom of the group.
