in 744240 20100526 230647 "John" wrote:

I am guessing that a washer has become so compressed that the plunger has
extended too far and then cannot retract as it has rotated out of alignment
with the hexagonal hole it slides in.

Not related to OP's question but why do some people feel it necessary to turn off
taps with as much strength as they can muster?
I'm constantly demonstrating how little effort is required to stop the flow.