Feels a little like deja vu but I am once again rebuilding brake calipers with stainless pistons. I have done this before on both sets on the 110 and the fronts on the 90. The set being rebuilt this time are for the station wagon as currently the ones fitted are seized on which makes moving it even by towing a challenge. I bought an old set at Malvern and have split the first one ready to clean everything up to rebuild. My question: is the slimy residue seen in the pic below just where water has contaminated the brake fluid either from neglect in use or subsequent storage, or is it something more concerning?
I plan of stripping, cleaning, and painting the caliper and ensuring all the galleries are clear before beginning to rebuild so am not particularly worried, just more curious.

Looks a bit minging, but I wouldn’t worry about it. A good clean and new s/s pistons with seals and she’ll be good again!

bluedog333 said:

Looks a bit minging, but I wouldn’t worry about it. A good clean and new s/s pistons with seals and she’ll be good again!

Click to expand...

I will give it a go over with a wire wheel
And then may sneak into the dishwasher when the wife isn’t looking before giving the inside a final buffing.

Hot water & a brush