PS parts kit o-rings

[Barry Wolk]

Are the large PS pump o-rings both the same size? One appears to fit and the other is slightly too small.

Does anyone have an exploded parts view?

[Egenolf]

Here the exploded parts view:



I think, the both o-rings have to be the same.

[Barry Wolk]

Thank you, I concur. However the two identical rings sent don't seem to fit the closed end cap recess like they do on the bearing side.

[Roger Zimmermann]

I remember a story at the Cadillac forum regarding a PS pump: one O ring from the kit was too thick, preventing the pump to create pressure. Unfortunately, I don't remember which one. I have to do a search, but sometimes I have no luck.
Anyway, remember that Saginaw is/was a GM manufacturer.
Edit: I found the topic: It's the O ring shown between the pressure plate and the pump ring. Unfortunately, there is no indication about the correct diameter from the O ring. Someone wrote that they are both the same. If you are using the seals from the kit and you have no pressure, you know where to search...Do you still have the old seals? They could indicate the approximate diameter

[Barry Wolk]

Yes, I will take some measurements. Thank you.

[Barry Wolk]

WTH??? The parts list clearly shows the same number for both O-rings. The o-rings have an OD of 2.693 as does the groove for the O-ring in the front cover. There is no groove in the back cover, just a shoulder that is 2.693" wide, making the stock O-ring not a good fit, almost a guaranteed leaker. The closest I've found is a 2.754 OD, .07 round. Is there a better fit to my 2.693 OD?

[Barry Wolk]

It turns out the original parts missed being made to specification. The rear cover was widened out to the next available o-ring size. Closer measurements showed I can use the 2.754" OD with no problem. I will have 9 extra Viton o-rings if anyone needs one. McMaster-Carr had what I needed.