Questioning Hydraulics on 69 Int'l Hydro 544

I am purchasing a 69 Int'l Hydro 544 with a 2200 bucket loader. What is the best way to tell if the Hydro is weak? Two things made me question it: 1) when put up against a large tree in low forward speed, and idling, the tires didn't spin until pushed the hydro further. It does have loaded tires so don't spin easy. 2) The bucket didn't go up when tractor at an idle - had to give more throttle. Maybe that is just the nature of the Hydro on this tractor? Does anyone know this type of tractor?

to test a hydro:
in low range, lever in the blue zone, maybe half throttle, the hydro should overpower the brakes. (the tree might be considered as better than the brakes.) in high range, same settings, hold the brakes and the tractor should stall. from your description of pushing against the tree, it sounds like the hydro is ok. a weak hydro would whine against a load like a standing good sized tree.
as to the bucket's behavior, i would expect slow response at idle. lack of lift capacity should be a function of the relief valve on the hydraulic system, not the hydro. hth.

Bill, thanks for the information. By blue zone you are referring to the slow portion of the hydro correct? So the fact that the wheels didn"t spin may be due to not enough throttle, and not a poor Hydro? That is good news. In high range, and same conditions the brakes should actually overpower the Hydro? I did hear a small whine in the Hydro when the bucket was going up but the owner told me that is normal. Is it?

on the quadrant where the hydro lever moves in the forward position, there should be a long sticker (decal) with marks on it to use as a guide of how far the lever is pushed forward. the area of maybe 50-75% full open was colored blue. that blue area was supposed to denote the prime settings for power/efficiency of the hydro.
did the wheels spin in low range after you gave it more throttle? from your first post, i thought they did. i would expect they should, even with loaded tires. the hydro will normally whine pulling a load. but if there is a problem with it, under load (like the tree) and in low range, it will whine and slip but not dig and claw.
the hydro runs off a pump hooked to the flywheel. everything else (remotes, steering) runs off a separate pump. there will be some noise from moving the bucket. i'm not sure if the noise you heard would have come from the hydro, unless the tractor was moving when you were lifting the bucket.
one other thing, if the tractor is a utility (swept back front axle), the way the axle is suspended wears a lot on the axle pivot bushings. if they aren't maintained well ,it will wear into the castings themselves. btdt. probably the weakest part of the tractor.

Bill, thanks again for your patience with a novice and an old tractor with no color markings that I could see. In the tree test the throttle was kept at pretty close to idle and the Hydro was at the low side, and the tractor just sat there with no real progress. So that doesn't sound like a problem - just not at the prime setting for Power right? Once the Hydro was pushed forward the loaded tires spun but the throttle wasn't touched.
The tractor wasn't moving when I raised the bucket and the Hydro 544 doesn't have a separate pump for hydraulics but runs off the Hydro. So that is why the Hydro under the seat was making noise whne lifting the bucket at a stop. Just didn't know if that sounded normal?
Thank you again for helping me to determine the condition of the Hydro. From what you have read does it sounds like it is operating the way it should? I have only left a deposit so far and don't want to get a tractor with a bad Hydro.

"the Hydro 544 doesn't have a separate pump for hydraulics but runs off the Hydro."

thats a new one on me. the 544 hydro parts breakdown shows either a 12 or 17 gpm pump, plus a 3 gpm pump, totally separate from the hydro pump.
anyway, i would try the hydro test in high range. i believe a weak hydro will show up better in high range. has the seller changed the hydraulic oil and filters at the recommended intervals?
from what you have said, it sounds like the hydro is working as it should. understand, that opinion is worth just what you paid for it. i have 5 hydros, and got fooled on only one.

Thanks again for your advise. I was told by the current owner that the bucket ran off the Hydro so obviously he isn"t too knowledgeable since you said there is an additional pump. By the looks of the grease fittings it didn"t look like he greased it in a while so I doubt he changed any of the fluids or filters. That is why I was asking about the Dyno since I don"t think he would know if it were bad. Thanks again! I"ll do that high range test when I go to see it again, and make sure that it stalls out.