[EricV]

You want silicone brake grease. Sold at any auto parts store under a couple of brands. Sometimes they have the little one time use packets at the counter too.

If you can get a replacement bolt, you could helicoil the caliper mount easily enough and end that problem forever. Take the good slider pin to the hardware store and find out the size/pitch if you don't have measurement tools.

 

[EricV]

I've never done a helicoil, but if the tap doesn't work how much worse could I make it? LOL

OEMs often use helicoils for aluminum parts that will be end user disassembled for service. Steel thread insert in the aluminum part. You can buy an individual kit that comes with the correct size drill bit, helicoil tap, installation tools and several helicoils, plus instructions. It's not a difficult job for most people comfortable with drilling and turning bolts.

My concern on just tapping the hole is how much material is left to tap. Taps remove material. A thread repair tool will form what's left w/o removing material, but that's a specialized tool that's not usually found at the local hardware store.

 

[EricV]

Advance Auto Parts - Down for Maintenance

I have an old tube of Sta-Lube synthetic brake grease left over from my wrench for money days. It takes a long time to use up a tube.