Is there any high temp grease or lube you can use to lube the pistons and other parts of the calipers?

 

The brake pistons should be lubricated by the brake fluid. You could use wheel bearing grease, but what parts of the brake system are you trying to lubricate?
Since you have a fixed caliper brake system I do not see a need to lubricate any of the parts.

 

lithium grease works

 

silicon brake lube for moving or sliding parts,moly based brake lube for the back of the pads to reduce noise,never use lithium grease or wheel bearing grease on the brake system and do not over lube.

 

Actually superchargedg is right you should not use wheel bearing grease or chassis grease in a brake assembly since it might run onto the friction surfaces when the temps get high. I guess all of us have some off days.

 

nice