Mabye i missed this part, but is there a reason you didn't just run a fox pump?
Used the escort pump because the housing would let me use a remote reservoir. I assumed the mechanical part of the pump was the same. It still may be. I might just need to only swap the pressure relief valve.
But, i did some more digging last night and think i have a lead. I think the issue is the way I plumbed my low-pressure returns. I found a lot of posts on the classic bronco boards about this as they all seem to swap to hydroboost on their cars. The hydroboost needs no more than 3psi of pressure on the return line. Basically it needs to be unobstructed.
example of whati found
Does anyone know the line pressure in the return line from the hydro boost back to the reservoir? I have a diagram for the proper way to connect the two return line to a T fitting then to the reservoir, but I was think on putting a hydraulic check valve on the return line from the hydro boost...
classicbroncos.com
I tee'ed the two low pressure lines together with a single return to my reservoir. I think this might be the issue. The return from the power steering rack is high-flow and constant, but the return from the hydroboost is small. The recommendation is that if you TEE the returns, the power steering line goes on the "straight" portion of the tee so it has a straight shot into the reservoir, and the hydro goes on the 90* leg.
Guess how i plumbed it? Not that way. Basically my rack and hydro return are pointed at each other and have to make the 90* bend into the return leg. The thinking here is the rack return is pushing into the hydro return loop causing backpressure issues. Makes sense to me.
My symptoms line up to some of the symptoms guys who have restriction have experienced, so i buy this theory. The problem is I plumbed my lines with just enough lenght, so i can't just flip the tee and try it. Would need to make new lines and do a little rerouting.
Going to get a 6AN cap and unhook the hydro return and cap the tee. I'll just put the hydro return into an empty 5quart oil bucket and give it a shot. I'll know right away if this is the issue.
If it is, i can try flipping the tee, but I might need to add a second return to my reservoir or pick up one of those 7.3L PS pump housings with two returns (pic above a few posts) and go that route. That would probably be the most ideal situation but i would have to abandon my remote reservoir idea.
How do the SN95 cars do it? Ford tee'd it, and has the hydro return coming into the tee on the 90* leg. So looks like more evidence that I need to swap my tee around and might be able to get away with that vs adding a 2nd return to the bottle
Blue would be hydro return and red is PS return from the cooler