BTW: What does "failing" mean to you in this case?
Sticking on flow regardless of being cleaned, rings changed, and lubed. (at least once by me).
One experienced buddy checked it and thinks there's something wrong with the spring.
The good one is on MY wing. I rinse and-hose flush after every dive day, and hang the wing up with the inflator
elevated so the salt doesn't drip down into the mechanism.
Can't say my friend with the bad one follows the same regime, but it fails on every trip.
The last trip she had a pro technician do a full overhaul and it still failed.
Wants to buy a new one. Can you blame her?