Now that the immediate problem is resolved, I suggest you consider why the pump was unable to prime normally. Was the blockage so severe?
My own experience is that I had a Sherwood pump with about 1,400 hours (on a 280HP Cummins) that seemed OK. However, even with a new impeller and new face plate, the pump could not prime the engine
from empty when adding antifreeze
into the raw water
strainer for winter lay up. This meant that I needed to pour antifreeze
in from the exhaust
end back into the engine
, whereas with my Westerbeke generator
wing engine, it was easy to suck the antifreeze through from their inlet strainers. Fast forward to getting the boat prepared for an extended Bahamas cruise
when I replaced the Sherwood pump with an (almost) identical new SeaMax pump. Now the system primes easily from the strainer. I think the difference was related to wear inside the pump. I suggest you look at how many hours you have on your water
pump. It may be time for a replacement or reconditioned pump. Incidentally, one advantage of the SeaMax pump configuration is that is eliminates that damned shaft key in favor of a splined shaft. I once lost
one of those keys down the inlet hose and had to tear the boat apart to find it!!!