Mercruiser 470 cam seal ????

[jstaguy24]

My new cam seals arrived today and im ready to start re-assembly tomorrow. The new seals are different then the old ones I removed.The old ones were the same on either side so the seal was identical no matter what direction you put it in. The new ones are solid on only one side and the other side is hollow and you can see the spring wrapping the seal. Im not sure which direction to install these. My guess would be to put the hollow sides on the inside (both sides towards the seep hole so one side seals out the oil, and the other seals out the water. But im not sure. Anyone who has done this repair and can let me know which way to put them in it would be appreciated
Thanks

 

[Don S]

Re: Mercruiser 470 cam seal ????

This from the service manual that you can download from the adults only sticky. You want manual #3.

 

[stonyloam]

Re: Mercruiser 470 cam seal ????

The function of the second seal is to keep any coolant that seeps past the first seal from entering the crankcase, so both seals face the water side. Any coolant that gets past the first seal is blocked by the second, and leaks out of the weep hole.

 

[jstaguy24]

Re: Mercruiser 470 cam seal ????

Great thanks for the info guys

 

[stonyloam]

Re: Mercruiser 470 cam seal ????

The new ones are solid on only one side and the other side is hollow and you can see the spring wrapping the seal. Im not sure which direction to install these. My guess would be to put the hollow sides on the inside (both sides towards the seep hole so one side seals out the oil, and the other seals out the water.

The convention is that the spring side should face the liquid being contained (pressure side). That is the springs (hollow side) on both seals should face the coolant (away from the engine). That always confused me too.

 

[jstaguy24]

Re: Mercruiser 470 cam seal ????

Dangit I put them in backwards then. I put the solid side facing the water side figuring that would be the most solid part of the seal. I hope it holds. Might as well try it now that its together. Just waiting for the sealant to dry and then I'll test it

 

[Don S]

Re: Mercruiser 470 cam seal ????

I hope it holds.

It won't ! You WILL get antifreeze in your oil. There is no oil pressure against the seals, there is water pressure, it will leak as soon as the cooling system starts building up pressure.

 

[achris]

Re: Mercruiser 470 cam seal ????

It won't ! You WILL get antifreeze in your oil. There is no oil pressure against the seals, there is water pressure, it will leak as soon as the cooling system starts building up pressure.

Agreed. Take it off and start again. If you don't, then you will be doing it anyway, but this time you'll be cleaning water out of the engine oil too....

Chris......

 

[stonyloam]

Re: Mercruiser 470 cam seal ????

Dangit I put them in backwards then. I put the solid side facing the water side figuring that would be the most solid part of the seal. I hope it holds. Might as well try it now that its together. Just waiting for the sealant to dry and then I'll test it

Dang here too, sorry I was so slow getting back, had to do some research to make sure I knew what I was talking about (not always the case), then reread your post and thought Hmmm.... that could go either way. I agree, better redo. Better safe then (really) sorry.

 

[jstaguy24]

Re: Mercruiser 470 cam seal ????

Thanks for the help guys. I got it switched around the right way this time. Thankfully I can do it all in place and dont have to pull apart to much