I was lucky enough to not have to clean mine.
If I had, I dont think they would have turned out so well.
Im upgradeeing to 256mm discs, so the £20 Mk2 GTi calipers were just the job
Disc cleaner is great for getting all the crap you dont see off the calipers.
So after cleaning with a wire brush, spray some brake disc cleaner (Can be bought from any motor facters for a couple of quid.) onto the caliper and the carrier.
Use some wire wool and wipe over.
Then use a tack cloth (What a bodyshop uses to remove any dust being painting) over it all, and paint on uses a good quality paint brush.
Ask for Hammerite Direct to rust Metal Paint.
You want to choose a Smooth finish.
The silver or Black paint also looks good for tidying up the Hubs while the brakes are off.
Here is what I used.
The Red spray was used for spraying the carriers, as the wierd shape makes it hard to get to with a brush.
The Calipers were painted with a brush, as it take a more durable finish as Im always knocking them when Im ajusting my coilovers.
And I always hit it when Im take the nuts out the wheels lol.
Take you time with it, and it will look great.
Pic is a little large to post.
But heres what you need.
Click Here.
Before and Ater
