So I have been reservoir drain and filling the pump for a few months now, maybe 2 times a month, and a couple weeks ago i disconnected return when the wheels were in air for rotation, pushed more fluid than just reservoir, and reconnected, filled with type f, and bled sincethat was good time. i also replaced the cap which had a broken tab on the side so it would slighlty open a hair on the side opposite the good tab.

I have original hoses, and they arent leaking* and it appears original pump. It still works fine, as far as a ford power steering pump of this era is concerned(sad face if comparing to the superior member of the market) but does work, seemingly consistently, and i dont loose fluid.
Because the system has original, old components, I wanted thoughts on what likely is causing black fluid. I dont know if its degredation of fluid or if its contamination, but if there is a good way to tell I would check. If I replace any lines I would do them both, but i would be plumbing a dedicated cooler and a magnetic filter because hydraulic fluid loves heat and ford pumps love heat too. so do saginaw. huh, it seems like hydraulic pumps running in bypass frequently and with a small fluid volume with laughable cooling built in is killer in a system where the fluid is often never replaced and nearly as frequerntly checked.

if that sounds like a shot at manufactures its because it is

 

You can swap in a Saginaw pump easy. Ford used them on the vans. Just need to swap the bracket out. Heck I have a bracket and pump in the garage now off a 5.8

As for the black color, I'd lean torwards hose degradation inside.

 

easy? Why yes, I own about 10 or so prob more Saginaw pumps in total half being p type pumps. Most factory, so a simple rebuild they would be better than most reman and a chunk of low quality new ones.

affordable? Not when you own a 4.9 and have ac with a serpentine belt and no yards nearby with e vans let alone anything older than 2000

because of bracket cost, cost to refresh a pump, prob would want to buy a new control valve, and two hoses, I’m looking at a hood chunk of money

im thinking when money is more abundant I would go for the Lee’s power steering pump which is a c2 externally but has the guts of, presumably, a Saginaw cb or tc pump. (P pump is too large ).

 

I6 Saginaw brackets are difficult to find. I was lucky when I found mine. There is a side by side pic at the bottom. Plus you need a different high side hose and longer belt. I have no clue what hose to run.

Just rebuild your CII if it leaks. Super easy and kit is about $8. Pop in new high side line for similar cost and follow it with a Super Cooling aka tow package cooler for more volume and fresh return line. Maybe $30 into it all. Can be crazy and install a filter on it like I did on the dually...it has a Magnefine.

My guess your hoses are degrading internally.

 

Have you tried adding white paint to the PS fluid? Might help with the color.
-Trolling aside, I've usually just gone by the motto of if it ain't broke, don't fix it.

 

im pretty sure red turning black like, within a day of replacing and driving, sorta qualifies on broke. Only the still functions broke, but the clock is ticking broke. Assuming the hose was what it is, which I thought, which seems to be agreed of the likelihood. You can only degrade the inside of the hose so much lol Eventually that means its outside or pressure is finding its way to the weakest point.