Check your hoses and a part of the pump housing I believe is called the
impeller cam. It is the piece that makes the impeller deform to cause the
water to travel down stream rather than possibly stall within the pump. It
is a replaceable part and one often overlooked.
"Jeffrey P. Vasquez" wrote in
message ...
Hello all,

I recently did a standard maintenance replacement of a raw water impeller
on a Yanmar 2GM diesel. Everything seemed straightfoward, part for part,
no leakage, everything went back together straight away and test runs at
the dock were nominal.

However, during a move to a new slip the engine alarm went off. A
subsequent check revealed nothing. Took the boat out and ran the engine
for a good hour and there were no issues. The second time out the engine
alarm went off again after about the same duration of running time as the
incident during the move to the new slip.

This time there was no curing it. I dismantled everything upstream and
downstream of the water pump and it appears there is no flow through the
water pump even though everything appears to be functioning exactly as
it's supposed to. The impeller is fine, the belt tension and pulley
function are fine and there are no blockages from the through-hull to its
egress.

The boat is a 1989 S2.

I am stumped. Any suggestions would be infinitely appreciated.

Thanks,

"The Carrolls" wrote:
Check your hoses and a part of the pump housing I believe is called
the impeller cam. It is the piece that makes the impeller deform to
cause the water to travel down stream rather than possibly stall
within the pump. It is a replaceable part and one often overlooked.

Thanks Jere and the Carrolls! It is profoundly encouraging to have such
quick and helpful responses. My thanks.

[This was cross-posted to rec.boats.cruising and a fellow usenetter there
wrote up an extremely good summary of shaft/pulley shear resulting in
exactly these symptoms, if you'd like to hop over there and read it.]

Thanks again!!

On Sun, 04 Jan 2004 19:29:28 GMT, "Jeffrey P. Vasquez"
wrote:


"The Carrolls" wrote:
Check your hoses and a part of the pump housing I believe is called
the impeller cam. It is the piece that makes the impeller deform to
cause the water to travel down stream rather than possibly stall
within the pump. It is a replaceable part and one often overlooked.

Thanks Jere and the Carrolls! It is profoundly encouraging to have such
quick and helpful responses. My thanks.

[This was cross-posted to rec.boats.cruising and a fellow usenetter there
wrote up an extremely good summary of shaft/pulley shear resulting in
exactly these symptoms, if you'd like to hop over there and read it.]

Thanks again!!


I had one impeller fail by the rubber coming adrift from the metal
bushing - everything looked fine, but the rubber didn't turn.




--
Peter Bennett, VE7CEI
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

On Sun, 04 Jan 2004 19:29:28 GMT, "Jeffrey P. Vasquez"
wrote:


"The Carrolls" wrote:
Check your hoses and a part of the pump housing I believe is called
the impeller cam. It is the piece that makes the impeller deform to
cause the water to travel down stream rather than possibly stall
within the pump. It is a replaceable part and one often overlooked.

Thanks Jere and the Carrolls! It is profoundly encouraging to have such
quick and helpful responses. My thanks.

[This was cross-posted to rec.boats.cruising and a fellow usenetter there
wrote up an extremely good summary of shaft/pulley shear resulting in
exactly these symptoms, if you'd like to hop over there and read it.]

Thanks again!!


I had one impeller fail by the rubber coming adrift from the metal
bushing - everything looked fine, but the rubber didn't turn.




--
Peter Bennett, VE7CEI
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

"The Carrolls" wrote:
Check your hoses and a part of the pump housing I believe is called
the impeller cam. It is the piece that makes the impeller deform to
cause the water to travel down stream rather than possibly stall
within the pump. It is a replaceable part and one often overlooked.

Thanks Jere and the Carrolls! It is profoundly encouraging to have such
quick and helpful responses. My thanks.

[This was cross-posted to rec.boats.cruising and a fellow usenetter there
wrote up an extremely good summary of shaft/pulley shear resulting in
exactly these symptoms, if you'd like to hop over there and read it.]

Thanks again!!