Rubber Protection

The bleed nipples/screws on my Wilwood SL6R brake calipers are steel with probably black oxide coating for mild corrosion protection. There is no protective cap or covering. Race caliper mah! Perfectly OK on a race car/kereta perang but if you daily drive your car through rain, etc. the bleed nipples will in no time develop some furry brownness aka rust which takes a lot of BST to remove only for the rust to return again shortly if the bleed nipple continues to be exposed to the elements. Even with weekly cleaning of my calipers and careful care rust still developed on one of my bleed nipples. Sigh...

For peace of mind I recently purchased the Wilwood Bleed Screw Cap Kit. The part number is 220-12487. Each kit comes with 8 EPDM protective caps. EPDM or Ethylene Propylene Diene Monomer is basically a type of synthetic rubber which is used in a wide range of applications. EPDM is compatible with brake hydraulic fluid and has good heat, ozone and weather resistance properties. Picture below of my Wilwood Bleed Screw Cap Kit. Cost came up to US$ 6.00 without shipping.

Each SL6R brake caliper features 2 bleed nipples so I actually need only 4 caps. Installation is DIY and a real PITA unless you are really good at teasing and massaging something with your fingers :P Picture below of an installed bleed nipple cap. The other bleed nipple is on the other side (inwards) of the caliper.