| Author |
Message |
    
Brian Powdrell
New member
Username: bpowdrell
Post Number: 3
Registered: 11-2011
| | Posted on Tuesday, May 01, 2012 - 10:41 pm: | 
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Hi,
I'm having an issue with the raw water cooling system of my Palmer P60. When I winterized this past fall it was working fine. I'm a bit of a rookie and made the mistake of making a lot of maintenance changes at the same time this past winter before starting it up this spring. Here is what I changed:
1. I changed the water pump impeller. I used the new paper gasket that came with the impeller. It was the same gasket that was used previously. I confirmed that the impeller is spinning fine as I ran it for a few seconds without the pump cover.. After I was still seeing pump priming issues, I painted the gasket with non-hardening gasket sealant as I thought maybe I had an air leak that was preventing proper priming.
2. I replaced several exhaust hoses using the same model of hose, only new.
3. I re-bracketed the water-intake strainer. It is now 3" higher than it used to be. I wonder if this has caused the water pump to not be able to prime. I've read that the hoses need to be below the water line but would moving the strainer a few inches higher really make a difference?
When I started the engine this spring I noticed there wasn't any water coming out of the exhaust. I tried disconnecting the hose leading to the sea-cock to suck water from a bucket but I didn't have much luck. This worked fine when I sucked anti-freeze this past fall.
If I self-prime the pump myself by turning the disconnected sea cock hose to be vertical and connect a funnel the water pump works just fine and I get a very steady stream of water shooting out the exhaust. Once I do this for a while I can quickly shut off the engine and reconnect the hose to the sea cock and the pump seems to remain primed just fine. I've run the engine for long blocks of time in my slip just fine after manually priming the pump.
However, I took the boat out for the first time last week and when I went to start the engine to come home the pump failed to circulate water and did not appear to be primed. My theory is that being on an angle while sailing exposed the sea-cock above the water line and the water pump is not able to re-prime on its own. The engine quickly overheated and luckily I was able to pull over to a marina and manually re-prime via the funnel and garden hose method I described earlier.
I can't for the life of me figure out why I'm having such a bear of a time keeping the water pump primed. I've read a couple of other related posts but I haven't been able to get to the bottom of it. Any ideas?
Thanks in advance,
-Brian |
kevin stone
Senior Member
Username: kdstone
Post Number: 57
Registered: 01-2009
| | Posted on Sunday, April 13, 2014 - 06:25 pm: |
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I wonder if this issue was solved or if anyone has any thoughts. I have started having a similar problem. Raw water pump is recently rebuilt. I have lost prime once in big prop wash from a passing large vessel and once in a big following sea. Pumped ok after priming. Also when i clean the raw water filter which introduces a little air into hose i have to prime the pump to get it pumping.
By the way the bahamas was great this winter. Warmer than usual. I didn't need pants until returning to florida. |
J.B. Castagnos
Senior Member
Username: jb_castagnos
Post Number: 909
Registered: 07-2002
| | Posted on Monday, April 14, 2014 - 12:25 pm: |
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Sounds like a leak on the suction side or the pump is not functioning correctly. Is it an impeller pump? it should pull a little vacuum at the suction side, check it at the pump with a gauge, if you get a reading, check it at the intake, reading should be the same. If it won't move the gauge, have the pump checked. |
kevin stone
Senior Member
Username: kdstone
Post Number: 58
Registered: 01-2009
| | Posted on Tuesday, April 15, 2014 - 11:08 am: |
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I did pressureize the hoses with a garden hose and found that the raw water filter was leaking a bit under pressure. It could have been sucking air. I relocated it lower down and where I could reach easier so I get it closed properly. I also ordered a new water pump as the housing of our current one seems worn to the point that my recent rebuild did not help. |
robert longworth
Member
Username: rlongwor
Post Number: 4
Registered: 09-2012
| | Posted on Friday, April 25, 2014 - 12:54 pm: |
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My pump on my P60 was not pumping well even with a new impeller. The pump intake is below the waterline as water will come pouring in when I take the hose off the intake. Turned out to be the ramp at the top of the pump on the inside had a small chip out of it and this prevented any suction from occurring. I replaced the ramp (West Marine ordered it from Sherwood) and it works fine
RL |
kevin stone
Senior Member
Username: kdstone
Post Number: 59
Registered: 01-2009
| | Posted on Saturday, April 26, 2014 - 08:57 pm: |
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Sounds similar to my issue. The cover plate for the impeller chamber was badly worn causing poor pumping. Replaced the pump and plan on rebuilding old as a spare. |
