My PSS seal has been trouble-free for three years or so, but the possible failure mode is something we all think about. I've got an inner tube sliced into a long rubber bandage. I figure I could probably wrap the whole mess tight enough to keep the leak manageable if the boot disintegrated... while I was around ... and able to see it right away ... and....

I have the vent-tube setup, which solves the air-bubble problem, but the little tube fitting would shear off without much force. I'm very careful when I'm back there working on the engine/trans, water heater, etc. I've got a nylon plug of the same thread sitting in the top drawer of the nav station in case it should come in handy.

I also keep a waterproof headlamp in a standard location. If I wind up doing a job like that, I figure it will take two hands.