The caliper slide pins are one of the most important - and most neglected - lubrication points in a brake job. Greasing them correctly keeps the caliper floating freely so the pads wear evenly. Here is how to do it right.
Why slide pins need grease
On a floating caliper, the caliper body slides on two pins so it can center itself and apply both pads evenly. If the pins dry out or corrode, the caliper cannot float - one pad drags or wears fast, and you get uneven pad wear and a possible sticking caliper. Fresh grease keeps them sliding.
Use the right grease
Use a high-temperature, RUBBER-SAFE brake grease (silicone or synthetic) on the pins - the pins ride in rubber boots, and ordinary petroleum grease swells and destroys that rubber; see copper vs ceramic grease. Do not use copper anti-seize here (that is for threads). The right grease is the same used on pad contact points; see where to apply brake grease.
How to apply it
Remove each pin, clean off old dried grease and any rust with a rag and brake cleaner, and inspect for pitting - replace pitted pins. Apply a thin, even film of grease around the pin, reinsert, and work it in and out so it distributes without hydraulic-locking the boot. Do not over-pack; a light film is enough.
Do it every brake job
Service the slide pins at every pad change, not just when there is a problem - it is cheap insurance against dragging brakes and uneven wear; see how to unstick a seized caliper if they are already stuck. Pair fresh, greased pins with quality pads and hardware.