What's the make (manufacturer) and model? That information will be pertinent before this question can be answered.
Should hold about 7 gallons.
15 gallons or approx 56 liters
A 2155 w/o 4wd holds 50 qts of hydraulic fluid. A 4wd takes 53.2 qts.
The only hydraulic fluid which is typically in a road tractor is the power steering fluid, and you simply fill that to the fill line on the reservoir. If it's been fitted with a PTO, that's an aftermarket system, and that, as well as the hydraulic tank, depends on who the aftermarket supplier is.
How much hydraulic fluid with how much gasoline makes a big difference and was some hydraulic oil mixed into the gas tank or was some gasoline mixed with the hydraulic tank. More info please.
Then you'll have excessive hydraulic pressure, and could damage the hydraulic system.
Depends largely on engine size. Bigger engines need more oil. Tractors require both engine and hydraulic oil. The hydraulic oil is used both by the hydraulic pump and by the transmission.
Internally, they're pretty much the same. The difference is the operation expected of it - a hydraulic pump converts mechanical energy to fluid energy, whereas a hydraulic motor converts hydraulic energy to mechanical energy.
40 lbs http://www.onlineconversion.com/weight_common.htm
It is 2.4 liters.
Hydraulic oil is very thin and will leak if it gets a chance. It does not burn out but after several hundred hours it may start to disappear Your transmission oil might leak into the engine or the rear end due to bad seals, however you have to determine how much oil you are using over what period of time. you will use some oil thru normal running conditions ,but not very much.
1.000 gram. Density of hydraulic fluid varies depending on type, temperature, elevation...etc. The SAE standard average is 1.000 g/ml at 77 deg. F (25 deg. C) assuming sea level.