As the title states, I made a stupid mistake.

I have a 2002 Millenia, base model (not the supercharged).

I put brake fluid in the power steering reservoir! Not just a little. I pumped the fluid out and replaced it with brake fluid. I have no idea what I was thinking and (maybe my mind was on the overall problem rather than what I was actually doing at the time) The BF stayed in the res. overnight, right after running up to the store on an errand. The next morning, the carport had a long puddle of fluid over it. I siphoned the BF from the reservoir and replaced it with PS fluid. I cranked and let it run a few minutes, then repeated again... twice to hopefully, either get it all out or dilute it to such a small amount that it probably wouldn't matter. Now, the fluid doesn't run out but it drops in the reservoir about 1/2" in 8-9 hours. I crawled under, pulled the plastic pan from the underside to see if I could tell where it's coming from. It appears to be slowly oozing from the shaft of the PS pump.

Now, will this seal eventually go back to normal size since the BF has been all but completely removed, or is there a way to pull the pulling from the pump and replace just the seal, or will I have to replace the pump?
Sorry for the long post, but wanted to give you the whole picture.

Thanks in advance for your responses.

 

OUCH!!! But don't beat yourself up too much. We all have or will make mistakes.

My best guess is no. Once expanded, the rubber in the seal will weaken and not return to normal size. I've never seen this particular case, but others where rubber was exposed to the wrong fluid and it never returns to normal.
Time to check the local junk yards, or parts stores, IMO.