Allis 7045 - Hydraulic Shenanigans

A while ago I posted about a 7045 that had (according to seller) some strange hydraulic issues His descriptions didn't add up (no power steering, diff lock stuck on, PTO working). I decided (for a while) to pass on looking at it, as I don't need another project.

More recently, he dropped the price (pretty much to scrap price), and I noted the rubber was good. Rears were the same as my White, fronts were the same as my combine - both which I desperately need new rubber for. So I decided to grab it, give it a quick once-over to see if I could get it functional, and if not I'd peel the rubber off, possibly pull and sell the 426 (which runs like a top), and scrap the rest. I'll still probably do this, and I'd still come out financially ahead. But I thought I'd spend at least a little time seeing if I can fix the hydraulic issues first.

Thus far I've pulled and replaced both sump filters. Both are now correct length, and I've verified the trap door is opening in the LH one and filling the sump housing. Old LH one wasn't stock and a little short, so I was hoping this might be my problem (no such luck). Pulled apart and cleaned divider/priority valve on the gear pump. The spool was stuck, but it was stuck in the up (priority/steering) position, so it really should still have had steering. Of course I left my hydraulic test box with everything I need to properly analyze pressures at my other farm, but to test flow at the gear pump I opened the test port, put a bucket under there, and fired it up for a few seconds - just to make sure I had flow and the gear pump was working. Absolutely nothing at all. No flow, and pretty much no bypassing when shut down (maybe 1 drop every 20 seconds).

This makes me think something is up with the gear pump drive - stripped drive splines were my first thought (assuming it has a splined connection between the trans and gear pump - I haven't dug into the parts books to know for sure). Clutch works (PD trans) and drives fine straight forward and back, so it seems the Geroter pump is working. The flamdoozler for me, however, is that the brakes work reasonably well. Which I 'think' means the piston pump is working 9but I could be wrong?). I understand that in normal operation, the piston pump is fed by the gear pump return from the power steering, but if this flow isn't sufficient it will draw from the surge cavity in the rear-end sump. which may be what's happening? Which has me flummoxed as to how the piston pump might be working and the gear pump not. But maybe the brake valves are such that the brakes can be worked (in some capacity) with no pressure from the pump - using just the pedal cylinders instead to have at least some pressure? Again: I haven't dug into the parts books to know for sure if this is how they're set up, and I foolishly left my service manual in my other truck at the other farm, so I don't have a schematic to look at.

Wondering if anyone has any thoughts about what the issue might be? Still thinking a broken/sheared shaft between the tranny Geroter pump and the gear pump is a likely culprit? In which case I'm guessing this tractor is pretty much scrap (I doubt new shafts are readily available? And if they are, a new shaft is probably more than I paid for the tractor). Next time I'm back there I'll check flow & pressures at the remotes - something I should have done before, but I only spent a little time at it and didn't have my hydraulic kit with me.

Any ideas greatly appreciated.