Just rebuilt my freshwater pump on my 3HM which was done aftermarket as it covers the engine ID plate. Was leaking just a bit but the bit caused some rust and ceased the engine kill switch on that side of engine Needed impeller change anyway ;)
John Conklin S/V Halcyon S/V Heartbeat www.flirtingwithfire.com On Jun 8, 2020, at 12:02 PM, Doug Mountjoy via CnC-List <[email protected]> wrote: David, You have a circulating pump usually driven by a belt off of the crank pulley, also this belt drives the alternator. This pump usually doesn't require any maintenance. There is a weep hole below the shaft to signal when a seal has failed. There is a thermostat that controls the temperature of the engine, on the output side of the fresh water side of the cooling system before the coolant enters the heat exchanger. Once again not much maintenance required unless the engine is either too hot or not getting to temp, around 180 deg f. Hope this helps. Doug On Mon, Jun 8, 2020 at 8:47 AM David Knecht via CnC-List <[email protected]<mailto:[email protected]>> wrote: I thought I might have had a problem with the fresh water side of the cooling system of my Universal M4-30 engine because it was heating water very slowly. I now think that it is just that the sea water is cold this time of year and it was taking longer than I expected. All was fine with lots of hot water after an extended motoring session at speed as opposed to idling at the mooring. However, it made me think about this side of the cooling system. Presumably, minimal fresh water circulates through the heat exchanger until the thermostat opens. My question is, what drives that water circulation. I know to check the impeller on the raw water pump side periodically, but I have seen no mention of doing the same for a water pump on the fresh water side. That pump appears to be pretty inaccessible on my engine anyway and nothing in the routine maintenance section talks about periodic replacement of an impeller there. So I am guessing it does not have an impeller that needs replacement, but I can’t find anything relevant in the manual. Thanks- Dave David Knecht S/V Aries 1990 C&C 34+ New London, CT <pastedGraphic.tiff> _______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray -- Douglas Mountjoy 253-208-1412 Port Orchard YC, WA Rebecca Leah C&C LandFall 39 _______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
_______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
