Raw water pump frozen?

[sonador]

I have fresh water cooling system on my boat and figured it was time to change the pump impellers. I've only owned the boat for one year so I don't know the last time they were changed. I wound up taking my raw water pump (Jabsco) off the engine yesterday as it seemed easier than digging out the back plate and impeller in situ. To my surprise, I was unable to turn the pump by hand. The pump worked fine last fall. Is this normal, or should I assume I need to redo the bearings?

Sonador

[starnesent]

dont know if its normal -

but the new pump turns hard too,but it does turn with help.

im familiar with auto water pumps & they do spin freely & easily by hand.

but the raw water pump [MMI] its new in box & i tried turning it with my fingers - nope im not strong enough to grip it.

i put a piece of wood [stick] carefully in the shaft slot & it turned smoothly & kind of easily with moderate pressure used in turning the shaft.

ive not had an old pump in my hand yet (thats next)

my guess is the impeller is rubber & it conforms to a small irregular shape
[not round] - friction is the result.

i wonder too if this is normal in the A4 pump world.
& shucks how much horse power is robbed to run the water pump?

[Don Moyer]

Sonador,

I'm not sure how hard you're trying to turn the shaft, but you should be
able to rotate the shaft of a flexible impeller pump by hand if the pulley
is still installed. I wouldn't expect you to be able to turn the shaft with
your fingers with the pulley removed. If your pump is in fact totally
locked up, my first guess would be that the ball bearings seized for some
reason.

Don

[sonador]

Thanks for the advice

Don,

I have the pulley on the pump and it won't budge. I've opted to purchase a new MMI 501 pump from you rather than mess around with rebuilding the old one.

Sonador