Awesome. Thanks for the responses.
I guess there is no way to prevent it, but only replace the caliper when it fails..
Boot failure does not mean you need a new caliper right away. If the boot tears the exposed part of the brake piston will over time show signs of corrosion. This is not a prob;em as long as the pads wear and the piston keeps coming out farter and farther. When it's time to replace the pads and you push the brake piston back in that's when you mess up the brake piston seal because you force the corroded piston back in. If the brake piston boot is torn, you need to rebuild the caliper before you install new pads.
1. remove the piston and clean it. If too corroded replace it. Usually they are not very expensive.
2.. Replace the brake piston seal. An inexpensive part.
3. Replace the brake piston boot. Also inexpensive. A caliper rebuild kit comes with seal and boot.
4. Push the brake piston back into the caliper. For rear brakes you will need a proper piston reset tool or you can get creative. The brake tool kit is maybe $50 but you can also rent one from your local auot parts store.
5.. Install new pads, shims etc
6. Bleed brakes. install speed bleeders and use a vacuum or pressure bleeder or ask a friend to help.
If that's too much work you can just buy a rebuilt ot new caliper but where's the fun in that? And I have come up with one product that may prolong the life of the brake piston boot. I don't see why 303 Aerospace Protectant would not extend the leife of the boot somewhat. It's a pretty effective protectant for plastic and synthetic and natural rubber.