Trying to figure out a D17 hydraulic issue...

So I've got a buddy who has a D17 that he doesn't know a ton about. It has a front end loader, and it runs. Apparently the front loader works just fine, but he has a rear blade for it but when he puts it on, it won't lift the blade up off the ground. He tells me several years ago it used to work, but one day it quit working so they took the blade off and have just been using the front bucket.

I don't know anything about D-17s (my knowledge stops at WD-45 stuff), but I had him send me some pictures (it'll be an hour drive for me to go investigate in person, so want to get some info in advance). Looks like a similar setup to a WD-45 with a 445 loader with the hydraulic pump run off the crank. So I'm assuming there's 2 hydraulic reservoirs? Anything simple to look at that would make the rear lift arms not work, like low fluid or stuck linkages or known issues with hydraulic pumps?

DrAllis wrote: A series 4  ????    The tall lever on the front of the console makes the arms go up (pull back) and down (push forward). Has he checked the hydraulic oil level ??? dipstick to the front left of the gear shift.

Yeah wish I had a better picture of the series number there. The fluid level is definitely first thing on my list to check.

Do these have a second reservoir for the loader hydraulics, or is it all just that one reservoir?

So those back two levers are the TB setting? And then the two short ones (by the tall one) are the remotes? And if I pull the remotes with nothing plugged in the pump should run and pull the engine down?

Also, oil recommendations? Just standard Hy-Tran type stuff these days?