Power steering pump parts question
 

I seem to be missing parts from what Ive seen of others and Im not certain the filter was installed correctly. I understand that several styles exist but i cant find information on mine.
When I removed the lid the filter was on top of the spring, one o-ring around the paper element, and another the same size laying in the bottom. There were no other parts like the plastic spring cover or spring retainer nut that Ive seen on others.
The element was very clean and not surprising because fluid completely bypasses the filter. But I also noticed the diameter of both filter and o-ring are smaller than the seat at the bottom and again, they cannot serve to seal anything.
Does anyone know how to find what part numbers I need for my pump?

You appear to have the right filter.
If desired, AFAIK the o-ring goes into the recess on the bottom of the filter (visible in photo #2).

The filter is installed first (seven small holes on top), then the spring, next the spring steel retainer/clip, and lastly the cover with the nut/wingnut.

There is no retainer clip. The the diameter of o-ring I found in the bottom(underneath the filter) is much smaller than recess on the bottom. I was able to obtain one that did but I’m not sure that filter even reaches the recess. It seem to seat snug along the top edge without an o-ring and there’s no recess or groove on the seven hole Side(top). I don’t see the need for a retainer as the lid hold the spring down and in place. I think I’m just going to run with it.
Thanks much for the reply.

no o ring needed
 

I have never seen any o rings used on power steering filters. The filter goes in first, holes facing up, then the spring and then the retainer or cap and wingnut.

One of the members mentioned there is ZF power steering pumps and Vickers power steering pumps. Perhaps one of then uses the O-ring.

Mine is a Vickers but I have not looked inside since like 2010 so I can't remember what is in there. I have never had any leaks.

Holy cow! There's supposed to be a filter in there? Mine doesn't have one.

Well none of the American cares I have owned with power steering more my Volvo have a filter except for a small screen in them and as long as they are filled with fluid they keep working but do leak on occasions.

Just as a talking point the do sell inline power steering filters that go on the suction side.