This is the second time I´m overhauling the complete set of brakes already. This time for my BMW K100 cafe racer project. I´ll document the process step by step here, but let me start with the end result first to make an impression.
BMW tends to "lock" all important screws with LockTite. So when you disassemble the brakes, make sure to heat up the brakes first using a hot air dryer. Be careful not to burn your hands! Always wear gloves.
I found the best way opening the screws is putting them into a vice and use felt to protect the brakes from scratches.
Uh, well. That´s a nice rubbish dump. It´s obvious all parts need to be replaced, seals, screws and pistons. Next step is removing the pistons. I use air pressure to shoot them out. ATTENTION! Never hold the brakes pistons over you face! Here´s why...
Once everything is disassembled, it´s time cleaning the housings. Idealy we have a ultra sonic but brakes cleaner, hot water and a bit of elbow grease works as well.
After cleaning the housings is before the paint job. And taping of course. It´s crucial all holes, threads and sealing surfaces are protected from laqueur. Not the most desireable job, but necessary.
I´m using wood dowels to close the holes and the old pistons (without seals).Just gently put them in again.
Et voila. Lacquered with 2K primer and finish wet in wet. The colour is already acid and heat resistant. (Though not cheap)
After a week or so we´re now good sanding the logos. Just put a sheet of sanding paper on a plain surface and gently move the logo section over it until all laccquer has been removed.
Puzzle time! Isn´t it amazing how many parts are needed just for the brakes?
And as said before, we´re using just new parts.
Let´s put everything together again. There´s not much that could go wrong, just pay attention to the different diametres of the seals and pistons. Also you want to use silicon oil on the seals before putting them in.
I let the photos speak here.