Thu, 05 Mar 2020 21:59:28 GMT
Should a seal or impeller perish the sea water flow into the fresh water cooling system will slow or cease, causing broken pieces of rubber to get stuck in the sieve of the heat exchange unit, causing overheating of the engine and damaging the engine head.
A useful tip here is to use 1500 git water paper to remove any minor corrosion, sodium deposits, hardened old gaskets, etc.
Remember to close the sea cocks before removing the impeller unit (or cover) and then ensue the sea cock is opened again once all pipes are reconnected and before starting the engine when done.
The video below shows howto remove the sea water feeder pipe to engine, dismantle the impeller housing from the engine block, change the impeller, seals, bearing, gaskets and/or o-ring and put it all back together again; by one of Southern Yachting Academy instructors.