What is this part? Power Steering Pump - High Pressure Hose Seat?

[pinemind]

Cross posting from yotatech as I'm not getting any response.

I was taking apart my power steering system this weekend to finally clean up after the previous owner's massive oil leak that gunked up the entire engine something fierce. When I finally got the power steering pump off, along with the low/high pressure hose, I set it down on the ground and let it drain. When I looked down, I saw this gold concave washer type object. It looks like it seats perfectly into the high pressure hole in the pump, and correspondingly mates up with the end of the flared high pressure hose.

However, I didn't see this in any of the parts diagrams or FSM, so I wanted to make sure before I put this all back together. I am painting the engine bay and the last thing I want once the PS is all back together is a leak because this was in the wrong spot, or orientation.

Can anyone verify that this part goes into the high pressure hose in the power steering pump? Also, if there is a part number I'd love to know it as it's strange it's not anywhere I could find. I'm guessing it's part of the high pressure hose assembly, which is discontinued.

This is me placing this back into the PS pump in the orientation I think it goes in (concave side facing up towards the hose).

 

[pinemind]

Anybody have any thoughts? I'm going to be reassembling everything soon.

 

[Cali 4runner]

Those are needed to properly seal the pump.

Toyota PS pump rebuild kit contains them. I believe you can buy them individually too. I would replace them.

1987 Toyota 4Runner SR-5, GLX WAGON 2.4L MT Gasket kit, power steering pump - 0444630030 - Genuine Toyota Part

https://massive.ua/image-catalogue/toyota/0444630030.jpg

You can see them here in the kit contents.

I believe this is the part number for the seat. But at that price you might as well just buy the whole kit.
1987 Toyota 4Runner SR-5, GLX WAGON 2.4L MT Seat, flow control spring - 4434312040 - Genuine Toyota Part

 

[pinemind]

Mystery solved, no thanks to the official Toyota Parts Diagrams (via partsouq). If you look through the two sections of the parts diagram containing the Vane Pump, there's one section where the "Seat" is mentioned. However, it's in the wrong spot clearly as it shows it integrated into the fitting on the low-pressure part of the Vane Pump. Also, there is no "Seat" on the Hi-Pressure assembly either, where I was pretty sure this part belonged:

Then looking at the other diagram, focusing on the Power Steering hoses, there is no mention of an external Seat on the Hi-Pressure hose connection to the Vane Pump. I figured if it were anywhere, it would be here since it's technically not a part of the Vane Pump, but floats between the hose and the pump. Still, no dice:

Last ditch effort was to check the FSM. And as always, this proves my single most valuable investment outside of my stubby Milwaukee impact wrench. SR-46 clearly shows the seat as being in between the high-pressure hose and the high-pressure connection on the Power Steering Pump (Vane Pump):

Furthermore, there is actually a section in SR-49 that talks about replacing this part, called the "Union Seat," language that is never seen in the official parts diagrams anywhere. What's interesting here, is that it seems from the factory, these Union Seats were actually screwed into the Power Steering pump, requiring an extractor to remove. However, if one were to replace it, they are only available in floating style (the kind I obviously have as it fell right out and was not threaded):

So this is the first time I haven't been able to find a part on the official Toyota Parts Diagrams. And I'm still not sure if the "Seat" mentioned in those diagrams, incorrectly placed on the low-pressure return fitting, is the right part. Luckily, I still haven't lost this part even though I removed it almost a month ago (checked last night). Therefore, no need to order a new one.

Hopefully this helps others who may find this part mysteriously appear after disassembling the PS system. Just go to the FSM first, I need to follow that advice from now on.