[RickMN]

It's not as rare as you might think. Sometimes when technians replace a caliper, they clamp off the brake hose to prevent draining the master cylinder. That works on a fresh hose. But on an aged hose where the rubber is brittle, the crimp doesn't release. When you apply brake pressure, the fluid squirts past the crimp and gets locked in the caliper, constantly applying pressure. Bottom line, don't crimp brake hoses.