Rust proofing!!
I use Wal-Mart’s equivalent of WD-40 and white grease in the aerosol can to rust proof or at least significantly slow down the progression of corrosion.
First I spray WD-40 into the part to wet the surface which creeps into the threads and seams then I spray white grease on to seal it and water out.
The WD40 thins and helps carry the grease into the threads, cracks and parting lines of the parts.
I have found that the white grease is very resistant to wash out even in areas that see significant water spray from the tires.
It is cheap and easy to apply or re-apply.
Do not spray on brake parts or e-brake cable rubber seals, it will cause them to swell and disintegrate.
Tim