Un-Sureflo!

Your right, they are abortionate pumps.
Shurflo will tell you they are not designed for domestic use.

Jabsco Par Max were not without faults.
However the later models seem to have cured the worst flaw which was using an ordinary microswitch in the pressure switch.
They seem to be about the best that I've found ...... my last one lasted 5 years of liveaboard use before the diaphragm in the pressure switch wore out. 
The pump itself was fine and with an overhaul kit is still doing good service

There's a few cheap and easy fixes but some prefer spending £50 now and then.

Bit like batteries really.