3.4L 2004 - Rebuilding power steering pump - pressure relief valve issue

Issue: I have no power steering at low RPMs, but power steering function kicks in above 1500ish rpms.

I'm looking for the parts to replace the pressure release valve within the PS pump but haven't had any luck finding the parts online. Anyone know where to find OEM replacement parts for this item?



Help finding OEM replacement parts for this valve is my main question, below is more info on diagnosing the power steering issue,, and some sweet pics..

The power steering had been getting heavy (heavy steering wheel) over time. I had never diagnosed a power steering issue before so the following are all the steps I took to finally arrive where I'm currently at now..

-Inspected the reservoir fluid with a Turkey baster, found dark nasty stinky fluid
-Started flushing/bleeding (OEM tools vacuum pump) the fluid several times, the fluid would go dark quickly over the first several flushes (by go dark quickly I mean, I would drive several miles then re-turkey baste the res to find the fluid be grayish and murky again)
-Over the several flushes the fluid started to stay clean, to help speed up the cleaning process I used sea foam trans clean.
-Once the fluid started to sustain in clarity and color the faulty symptoms changed entirely.
-Symptoms went from a heavy steering wheel, to: NO power steering at low RPMs and decent power steering at anything above 1500.
-Then, I took the pump out of the truck and rebuilt it with a Toyota OEM seal kit
-Upon inspecting the insides of the pump I did not see anything worn or abnormal, it seemed fine, I replaced the old seals while having the pump apart..
**I however did not disassemble the pressure relief valve to check its condition which I believe is accessed via the bolt that is circled in the pic below.



While taking the pump apart the one the one thing kept the pump spindle locked inside the housing was a small snap ring. I thought it was funny to find that this little ring kept this thing that rotates so aggressively in place. The more I venture down this DIY mechanic road (which has been quite a bit of fun) the more I'm amazed at what stands in the way of catastrophic failure.

Here's a random article describing the function of the pressure relief valve of any power steering pump, useful insight: https://benchworksteering.com/blogs/tech-talk/pressure-relief-valve-troubleshooting

Any insight on my questions is appreciated, thanks in advance.