[1 Lucky Texan]

I've wondered about some type of 'radiant barrier' silver-colored spray paint. It would have to be heat resistant, flexible and not diminish the lifespan of the boot material.

Dorman makes some silicone 'universal' replacement boots. But the 1 or 2 reviews I saw were not positive.

 

[1 Lucky Texan]

If they are already cracked, nothing is gonna help. The rubber molecules become cross-linked and it's unlikely anything will undo the damage from heat and age.