Ford 5000 Row Crop Hydraulic Issue

I have a 1971 Ford 5000 Row Crop (5200) and I am at my wits end trying to figure out the hydraulic issues. I purchased it without trying the hydraulic remotes, rookie mistake I
know, and knowing the lift came up slowly, extremely slow, but it did come up, and the PTO was operational. I just figured the slow lift was a severely clogged filter or screen, or the
lift cylinders were in need of rebuild. This unit does not have an external filter, only a small cartridge one in behind the pump and a stainless steel pickup screen. I decided to drain
the oil and check the filter when it wouldn't pick up an empty 110 gal boom sprayer and had no pressure at all at the SCV when I hooked the gauge to it. I found a lot of black sludge
in the screen and filter, and all through the bottom of the housing. I cleaned it all out with gasoline to flush the black sludge out and I ordered a new pump. I filled the transmission
and rear end up with new oil and thought I would have the problems fixed. I was wrong. I then began emailing the only mechanic at the local CNH dealer that knows about these
tractors, told him all of this information, and he said that I did correctly replacing the pump when I didn't have pressure at the SCV and the lift arms wouldn't lift up. He said the SCV
takes priority over the lift arms and that something inside of it could be the problem letting the fluid bypass and not build pressure. I then removed it and I didn't see anything that
would've caused any issues, at least I think. While it was off I turned the engine over with the kill switch pulled out so it wouldn't start, and had fluid began coming up from one of
the ports. It wasn't much pressure at all, but it wasn't running or constricted so I figured that would be normal for this. I put in new O-rings, and reinstalled it. Im using it currently
with the arms locked up with a draw bar mounted cradle to hold my sprayer up. My PTO is still working because it runs off of low pressure and the mechanic at CNH said it was a
"double pump" and it would run the PTO on low pressure. I am trying to find out where I should go next. I plan on taking the top lift cover off this winter during down time, I just
wanted to see if there was anything else that I could try someone else might've already done or I am overlooking.

Thanks

The sludge could be a algie or bacteria growing in the system. in which case you need to flush, flush flush and then treat it with a biocide.. but..

have you put a gauge on the remotes to check the pressure. The remotes when operated, should get the pressure before the 3 point.... and thus show the pressure on the pump...


so that means anything wrong in the 3 pt will not affect this reading.


Grasping at straws.. with new pump, I would worry that the pickup tube is cracked????, or tube between pump and top cover gone??? if thats possible.

I did put a gauge on the SCV and had no pressure at all. Some fluid dribbles out after removing the gauge, but no pressure registering on a 3500 Psi gauge.

As far as hydraulics go, the PTO is the only operational function I have.