Tractor Repair: IH 706 tractor, torque amplifier, hydraulic oil

Question
When I go down a steep hill it feels about 50% of the time, as if it is not in gear. and I must brake continuously to get down the hill, it has a torque amplifier

Answer
Try this drive your tractor in a low range and then mash on the brakes.  If the engine does not lug down then I think your problem is the clutch is slipping. If it does then we need to look at your hydraulic oil level. You might have a problem the pump picking up oil.