Mercruiser 470 water pump seals orientation

[sroger007]

Just repairing the typical water pump leakage problem on my 1980 470 Mercruiser. The problem I have is what orientation is correct for the two cam shaft seals. When I took the old ones out they were both facing in the same direction (cup side facing out). This makes sense for the outer most seal (coolant side) but doesn't seem right for the inner oil seal. Seems to me the cup on the inside seal should face cup in towards the engine block to stop oil from leaking out into the bleed passage. I'm thinking the seals were replaced before and the oil side seal was installed incorrectly. Can anyone clarify the correct seal orientation for me. Thanks

 

[achris]

Re: Mercruiser 470 water pump seals orientation

Roger,<br /><br />Welcome to iBoats.<br /><br />Just looked in the Merc manual and the way you see them is the way the book says to replce them. Personally I agree this you, but this is the way the book says, <br /><br />"Both water pump seal lips face water side or front of engine".<br /><br />Chris...........

 

[sroger007]

Re: Mercruiser 470 water pump seals orientation

Chris,<br /><br />Thanks a bunch. Makes no sense to me but it is what it is. I may go out on a limb and install the oil side the way it would seem to make sense. I have a day or two to contemplate before I have to make the plunge<br /><br />Scott

 

[DHPMARINE]

Re: Mercruiser 470 water pump seals orientation

Outer seal is to keep water from the engine Yeah I mean coolant.If it fails,coolant will drip from the pump.The inner seal keeps coolant from entering the crankcase.<br />No need to keep oil out,crankcase is lower down,and no pressure at the cam shaft.<br />DHP<br /><br /><br />and yes it can be confusing,but no oil 'resevoir 'to keep out and yes,the surface of the shaft is probably worn.Use readi- sleeves,and position them accurately.

 

[sroger007]

Re: Mercruiser 470 water pump seals orientation

DHP<br /><br />Again musta had my head up my butt. Of course there is no oil pressure in the "open" areas of the engine, only in the oil passages to the various bearings surfaces - what was I thinking?. <br /><br />Readi-sleeves are already installed - easy as pie to do. Just cleaning up the covers and ready to install new seals. See no issues. Thanks for all the input