Brake Caliper REBUILD and ASSEMBLY 

No you don't lubricate those type of slide pins.

Why not ?

​@@Rockyboy120 The elasticity of rubber pulls these pins back and if you lubricate them, the lower part of the caliper will not go back as much as the upper part(because of weight) and the pads will wear slightly at an angle. These types of calipers should not be lubricated. These pins run dry, another story is with pins that works inside caliper these one we lubricate but with proper grease that doesn`t swell rubber. If we lubricate them with the wrong grease they may even seize.

That’s interesting, I was not aware of that, thanks.

Or red tacky, since it’s a grease compatible with the dot four and 3

ATE company says they can't be lubricated. But why not.

You don't lubricate them.

No never in my life have I seen this done

There is nothing absolute about using brake fluid. As I understand, red rubber grease may also be used.