Before we re-insert the caliper guide pins into the caliper housing, they need to be properly lubricated. But remember, it's always best to check your vehicle's service manual before doing this kind of work.
You're going to need some high-temperature grease. This is a synthetic lubricant designed for machinery that can withstand temperatures of several hundreds of degrees Fahrenheit. Brakes generate a tremendous amount of heat because they're essentially a piece of metal used to slow down another piece of metal moving at highway speeds. The last thing you'll want is for the lubrication on your brake caliper pins to be unable to take the heat.
First, thoroughly clean the brake caliper guide pins, removing any excess grease or dirt leftover from when they were inside the caliper. Coat them in a layer of the high temperature grease. From there, you can re-insert the pins back into the caliper housing. They should slide right in if you used enough grease. Once those are back in place, you can complete the rest of your brake work -- like replacing the pads and reinstalling the caliper.
Some auto repair shops will skip the step of lubricating the guide pins. But while some say it's not essential, it's a good step in keeping your brakes operational and making sure they can stand up to the wear and tear they'll face on the road.
For more information about brakes and other related topics, follow the links on the next page.