When I winterized my boat in Nov, 2022...she circulating the antifreeze perfectly fine. I started the engine, prior to going in the water last weekend, and I could not get the system to circulate water. Didn't matter how I positioned the bucket. Thinking it needed priming, shouldn't, I put a funnel to the inlet hose and I had a good flow exiting the exhaust but could not maintain when putting the hose back in the water bucket.
I then replaced the impeller, even though the original was perfectly fine. Still no flow. Took the impeller back plate of to confirm the pump was spinning it and it was.
Went to the thermostat, removed it and put the housing back in place.....still no water circulating.
What's left? I confirmed no blockage with the funnel earlier.
Could it be that the pump is not creating enough vacuum to get a proper draw from the raw water strainer?
1978 CD28 - Raw Water not Circulating
Moderator: bobdugan
Re: 1978 CD28 - Raw Water not Circulating
You mentioned the strainer - perhaps you have an air leak there. It could be at the hose connections or more
likely the cover. Perhaps the gasket or O-ring is old and not sealing. It wouldn't hurt to buy a new gasket and
install with some glycerin.
Another possibility is a crack in the bowl. If sea water was left in there over the winter, it could have froze and
cracked the bowl. Good luck - Jean
likely the cover. Perhaps the gasket or O-ring is old and not sealing. It wouldn't hurt to buy a new gasket and
install with some glycerin.
Another possibility is a crack in the bowl. If sea water was left in there over the winter, it could have froze and
cracked the bowl. Good luck - Jean
Jean - 1983 CD 33 "Grace" moored in
Padanaram Harbor
Massachusetts
Padanaram Harbor
Massachusetts
Re: 1978 CD28 - Raw Water not Circulating
like he said: make sure your strainer is sealed .. maybe put some silicon on the gasket. or bypass it to make sure. my raw water pump draws water with over 6' of hose from the seacock.
-
Carl Thunberg
- Posts: 1284
- Joined: Nov 21st, '05, 08:20
- Location: CD28 Cruiser "Loon" Poorhouse Cove, ME
Re: 1978 CD28 - Raw Water not Circulating
Sorry to ask the obvious question, but is the raw water seacock open? It needs to be in the closed position to draw from the bucket.
CDSOA Commodore - Member No. 725
"The more I expand the island of my knowledge, the more I expand the shoreline of my wonder"
Sir Isaac Newton
"The more I expand the island of my knowledge, the more I expand the shoreline of my wonder"
Sir Isaac Newton
Re: 1978 CD28 - Raw Water not Circulating
The boat was not in the water but on jack stands. I removed the inlet hose from the seacock and connected a 3ft extension in order to place in a bucket of water.
I winterized the engine so there was no lake water in the system at all.
I winterized the engine so there was no lake water in the system at all.
Re: 1978 CD28 - Raw Water not Circulating
how come you don't connect the intake hose to the seacock instead of a bucket?
Re: 1978 CD28 - Raw Water not Circulating
You should be fine with your approach. I do this routinely as I prefer not to leave my heat exchanger full of salt water. In my case, I have a T with a valve connected to the inlet hose which I put in the bucket full of fresh water after every sail, but your solution is fine.
My first comment is to try it with the bucket above the water pump level to see if that helps or even take a turkey baster and pre-fill the inlet hose to help it prime. It sounds like the water pump is sucking air but a good pump should be able to suck lots air, sea weed, small pilchards, etc. before there is a problem so it is not a small air leak.
A 2nd comment. There were reports few years ago of defective impellers, where the attachment between the brass ring and the rubber was defective. When the engine ran, the shaft turned, the brass ring turned but the pump would not pump because the vanes were stationary. Inspection looked normal, but they would not pump, or would pump for a while then one day fail catastrophically. I'd expect stragglers from that lot are long gone to the dumpster, but if you managed to find one, that could explain the problem.
Steve Bernd
My first comment is to try it with the bucket above the water pump level to see if that helps or even take a turkey baster and pre-fill the inlet hose to help it prime. It sounds like the water pump is sucking air but a good pump should be able to suck lots air, sea weed, small pilchards, etc. before there is a problem so it is not a small air leak.
A 2nd comment. There were reports few years ago of defective impellers, where the attachment between the brass ring and the rubber was defective. When the engine ran, the shaft turned, the brass ring turned but the pump would not pump because the vanes were stationary. Inspection looked normal, but they would not pump, or would pump for a while then one day fail catastrophically. I'd expect stragglers from that lot are long gone to the dumpster, but if you managed to find one, that could explain the problem.
Steve Bernd