This all depends on which tractor you're on at the time.
The older Fords 8N's - Jubilee's - etc. had a dip stick on the side of the transmission.
A lot of the older International's - you needed to take a twig and stick it down the reservoir.
Most have a top off hole. Meaning that you add fluid until it runs out of the top off hole. Then you put the plug in and the fill cover back on and it's full.
Go to tractorshed.com for specific help on your model.
The location of the hydraulic oil check depends on your make, model.
how do I check oil in the rear end of a 3600 ford tractor
1 - Check the hydraulic pump. Shaft. Rubber gasket. Bearing. 2 - Check the oil pipes. Junction. 3 - Hydraulic cylinder and piston check. Oil leakage. Leverage.
Hydraulic fluid is hydraulic oil.... as for the type you use, depends on your system. I used to own two tractor-trailer end dumps, and I actually used ATF rather than hydraulic oil. Check with the OEM for your hydraulic system before you do this, though.
Mobil 424 hydraulic transmission tractor oil or Amsoil tractor hydraulic transmission oil
You should consult with a tractor manufacturing company. Or high-pressure hydraulic oil to use.
Right next to where to PTO shaft comes out of the back of the tractor there is a sight glass for the hydraulic fluid.
Dipstick
what is the hydraulic pressure and flow of a ford 3600 deisel tractor
what kind of hydraulic oil should be used for a massey furguson 245
plug in side of tran or dipsteck
The dipstick and fill plug are located in front of the gearshifts on the right hand side of the transmission.
oil, air, hydraulic, fuel, air conditioning,