1. Take the caliper off.
2. Take the pads out.
3. Squeeze brake pedal.
4. Spay caliper with brake cleaner.
5. Take one piece of Brick Banding and wrap round exposed brass pistons.
6. Clean all the gunk off brass piston.
7. Apply pink brake grease.
8. Squeeze pistons back in with finger pressure.
9. Put new pads in.
10. Put calipers back on bike.
Do this every few thousand miles, brakes will work.