Scavenge Pump Shaft Seal

[930LDR]

Which direction does the shaft seal get installed on the scavenge pump? should the solid surface face the cam tower or inwards towards the pump?

[HawgRyder]

With any seal...the open side of the seal (C section of it) goes toward the pressure.
That means...the pressure will tend to tighten the rubber against the shaft as it works.
If you install it the wrong way...the pressure will tend to lift the rubber off the shaft.
Hope this helps.
Bob

[930LDR]

Thanks Bob... so if I interpret your response correctly, the open side of the seal should be open towards the scavenge pump rather than the cam housing. Is there really any pressure there as the housing is open to allow the belt for the air injection pump to pass through.

Thanks,

[930LDR]

Maybe I'm thinking about this wrong... Is the pressure actually coming from around te camshaft, therefore the flat surface should face inwards towards the scavenge pump?

[HawgRyder]

I am rethinking the problem....with a scavenge pump...the suction of the pump would make the sump area of the engine the high pressure side....and the inside of the pump the low pressure area.
So...seal "C" section (the one with the spring) should probably point to the case side of the shaft.
That sound right?
Bob

[sjf911]

At least in the one I have R&R'd, the open side (spring) of the seal was to the inside of the pump.

[930LDR]

My poor memory would suggest that the original was oriented the same as Steve's but I'm just not dead certain.

[HawgRyder]

Perhaps the spring side was to the inside because at that point in the pump it was the pressure area?
Also...there are such things as double sided seals....one side to keep pressure in...and the other side to keep dirt and low pressure out.
Bob

[930LDR]

Interesting... There must be a prescribed, rather than theorized, answer to this though. I do appreciate the education nonetheless.

[xbmwguy]

Just removed and installed the seal and o ring and the flat side is up and is easily pressed in

[HawgRyder]

Nothing like having someone eyeball an original install.
I guess that mens the inside of the pump is a higher pressure than the outside.
Bob

[930LDR]

So I think there may have been some confusion and most of it was due to the poor wording of my original question. There are actually two shaft seals in the pump and air injection pulley assembly. One on the actual scavenge pump which is very small and a larger one that is on the air pulley housing that attaches to the cam shaft. Its this larger one that I had been enquiring about and I think my identification of it as the scavenge pump seal screwed things up. Attached are some pictures of the seal in question that were provided by another forum member.

Thanks for everyone's input.

[sjf911]

That is the correct orientation.

[proffighter]

But that's not the scavenge pump seal, it's the camshaft seal...

Here you can see both: