I did some brake repairs some time ago to my daily driver, a 1988 318I. I bought this car last autumn and according to seller brakes has just been overhauled (which can be easily seen from the pictures...)
Here's the starting point. 20 years of use has left some marks on the caliper (this was the best one..)

Since i am lazy i wanted the cleaning process be as simple as possible. I put disassebled calipers to citric acid bath for several hours.

Seems like acid has been removed some rust and dirt from the caliper

Parts after rinse

Since all the rust did not got loose, i decided to sand blast calipers lightly

I installed new gaskets and piston before the paint job, mainly because i was in the hurry (F1 in Monaco was just about to start) and usually fresh paint job will be ruined when you assemble parts.

When all the internal parts were installed i heated calipers a little bit and added zinc paint on them. After the zinc was dried i painted calipers with black header hot paint.
The end result is here

Here's my other cars brakes. A little bit bigger than BMW ones. And yes, they are Brembos. Originally fronts were under GT2 and rears under GT3. Now they will be installed under my 951. In the picture you can also see special adpters which make this installation possible. Adapters has been designed by my friend and i; they were made by a local machine shop.
