Power Steering Pump Rebuild - Which Way Seals Go?

[stephenson]

OK - so this is pretty straightforward, but the seals are small enough and the old ones so brittle they fell apart, that I can tell which way the shaft seals go back into the housing ...

Are there any rules of thumb in this case, or can one tell from the attached photos?

Both new seals have raised manufacturers' information on one face - nothing on the other. Both seals, per norm, have one shaft seal lip that is slightly more proud to the seal than the other. One face has a bit more material on one side than the other - this is the same face as the one with the manufacturer information - the other face appears to be more "open."

Both seals have concentric springs on each face - again, one of the faces is more open ...

I would hate to put this back together incorrectly - I have placed both in the photos with the "open" part of the seal facing into the cavity - the manufacturer markings are up ... seams like this is correct way since will have to seat the seal by pushing on the face that has the most material for pushing?

Would appreciate any help, general rules of thumb on seals and your impression after reviewing the attached ... thanks!

[whunter]

1991 350 SDL.

Sorry, No data on the tandem pump rebuild.

Try to apply seal theory/logic = The inside of these seals is exposed to pressure, outside is atmospheric or very low pressure.

FYI:
This is part of why I take so many pictures of my work coming apart.




Have a great day.

[stephenson]

whunter,

Thanks ... my logic, as well ... I carefully examined the old ones and due to badly deteriorated state could not tell much about them ... very brittle, as were every oring I removed, all broke immediately.

Jon LeChevet had commented off line same logic as yours - looks like net then is that both seals "face" toward the front of the pump (driven end) with back side of the front one facing away from the front chamber (only drain pressure in this chamber?) and the back one facing away from the higher pressure pumping chamber. So, both end up with manufacturer markings toward the driven front of the pump.

Thanks, again - this has been a very easy R&R so far - could do what have done so far in about 1/10th the time next time!