Johnson water pump.

[sunquest]

The bearings on my Johnson water pump which is fitted to my Fischer Panda generator seized solid. At around £160 for a new pump I decided to repair it myself. The bearings "O" ring and rubber shaft seal are readily available from bearing shops, My question is - which side of the rubber seal should the "O" ring go? In front ie the impellar side or behind the bearing side. Appreciate your help. Geoff

 

[Poignard]

The lip in the centre of the seal should face the liquid to be contained.

The one nearest the impellor should face the impeller i.e. the water

The one nearest the engine should face the engine i.e the oil

The o ring that fits on the shaft should be between the seals. It is there to throw any water off the shaft so that it comes out of the holes in the pump casing, so that warns you if a seal has failed

 

[spannerman]

Behind the bearing side as it will get in the way on the impellor side, if there are two seals it will sit on the shaft in the middle, it acts as a slinger to throw any seawater that leaks past the seal away from the shaft so it doesn't get past the engine seal.
Make sure the tension spring in the seal is made of stainless steel, otherwise if its an ordinary seal the spring will vanish in seawater and the pump will leak.

 

[sunquest]

Thanks Twisterowner and Spannerman. All makes sense now. Geoff