My rebuilt water pump pumps air instead of water...the bubbles come from under the boat---no water thru the exhaust. Could they have reversed the impeller? Thanks for your reply
Engine water pump
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The pump could be pumping, but you have a blockage downstream. A broken vane or a stuck shut thermostat could be at fault.
On the intake side, make sure your seacock is open and your strainer is clean.
You could take the cover off to check the vanes on the impeller, but I think they would correct themselves if put on backwards. I would also disconnect the out take hose a crank the engine to see if the pump is working. If it is, you have blockage further down the system.
On the intake side, make sure your seacock is open and your strainer is clean.
You could take the cover off to check the vanes on the impeller, but I think they would correct themselves if put on backwards. I would also disconnect the out take hose a crank the engine to see if the pump is working. If it is, you have blockage further down the system.
Sounds like
Sounds like you may have the hoses reversed.. They suck from one inlet and pump out the other. If you have bubbles coming from the seacock it could be that the hoses were connected backwards. Most impellers can rotate and be installed either direction so they really can't be installed backwards.....
Water Pump Reversed
I think that the pump can be mounted in the bracket 180 degrees out. Sounds like that is what happened.. Remove the bracket and rotate the pump 1/2 turn in the bracket, which will reverse the hose ports .. Should be fine .. The cam should be in the top right quadrant of the pump as it is mounted, looking toward the shaft. The pump is in the bottom left of the picture mounted on a swing bracket and belt driven clockwise.
I think that the pump can be mounted in the bracket 180 degrees out. Sounds like that is what happened.. Remove the bracket and rotate the pump 1/2 turn in the bracket, which will reverse the hose ports .. Should be fine .. The cam should be in the top right quadrant of the pump as it is mounted, looking toward the shaft. The pump is in the bottom left of the picture mounted on a swing bracket and belt driven clockwise.
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It's a raw water pump
so the impellers are operated by the shaft going into the engine and that shaft can only move one way, regardless of the impeller insertion "direction" because the vanes will straighten out in a nanosecond once the shaft starts. "Least they are on our Universal M25. As the last responder pictured, other engines might be different, i.e., belt driven, but if they can only operate in one direction, you could either twist the pump 180 degrees or correct the hose connections - same thing. Make sure the thru hull is open and clear and that the hoses are connected properly.
Then find the "knimknulls" who did the work, show them the problem they created, smile and say "No more of my business for you, I can do it better myself!"
so the impellers are operated by the shaft going into the engine and that shaft can only move one way, regardless of the impeller insertion "direction" because the vanes will straighten out in a nanosecond once the shaft starts. "Least they are on our Universal M25. As the last responder pictured, other engines might be different, i.e., belt driven, but if they can only operate in one direction, you could either twist the pump 180 degrees or correct the hose connections - same thing. Make sure the thru hull is open and clear and that the hoses are connected properly.
Then find the "knimknulls" who did the work, show them the problem they created, smile and say "No more of my business for you, I can do it better myself!"
Reversed hoses
I think the reversed hoses is the most probable cause. While a plugged intake or hose would stop water flow, don't see how it would cause the back flow of air, which you apparently have. Same with a blockage above the pump.
I think the reversed hoses is the most probable cause. While a plugged intake or hose would stop water flow, don't see how it would cause the back flow of air, which you apparently have. Same with a blockage above the pump.
Yup, Easy and Maine are right but the cause is that the pump is flipped in the bracket. When you turn the pump 180, the ports will reverse and it should be fine. You can see from my posted shot that the hoses would be tough to reverse. Stu is correct.. if it has been pumping air the impeller is probably toast and should be changed out before trusting it.
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Kloudie,
His engine has the pump mounted to the engine, not like the belt driven Yanmars. No way pump can be reversed, but would be pretty easy to switch the hoses if you weren't paying attention. Everyone is correct about the impeller. Put it in the trash.
His engine has the pump mounted to the engine, not like the belt driven Yanmars. No way pump can be reversed, but would be pretty easy to switch the hoses if you weren't paying attention. Everyone is correct about the impeller. Put it in the trash.
Ohhh Man.. I assumed that he was talking about a 3 GMF .. standard on most (old) 34's .. but I know some were equipped with Westerbekes and the new ones have the engine driven pump.. and ya right.. on those, the hoses can be easily reversed.. My Bad..
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