On Mon, 15 Jan 2018 05:12:58 -0800 (PST), wrote:

snip

Having undone that screw on pumps while running and observed resulting graunching noises and stalling, I am therefore the one that has the fact on that.

Could that be because the pump may have been stalled because of either
debris in the impeller or a failed bearing and you moving it again
simply highlighted that fact? shrug

Cheers, T i m