Checking Fluid Levers

80/90 gear oil in the front axle ,and 15/40 diesel engine oil in crankcase,

On Chinese tractors, screw-in dipsticks are read while just resting n the hole, not screwed in.  The engine dipstick just pushes in on mine, and is read pushed in.  The cap in front of the seat is for the gear case – 80W/90 gear oil goes in there.  Ditto for the front axle – there are fill ports on both ends of the axle and are usually painted red.  The hydraulic lifter box has a fill port to the rear of, and under, the seat.  Fill with AW32 hydraulic oil.  Don't overfill or it just drools out when you go up steep hills.  The injection pump uses motor oil, fill to mark on dipstick or to tell-tale hole, whichever yours has.

Given proper maintenance intervals, along with head bolt retorqueing at 100 hours and constant attention to keeping things lubed and bolts tight, your engine should last for a couple thousand hours or more before needing any tear-down.  Ignore the proper maintenance and you can kill it in very short order.  Diesel engines require good maintenance as they work very hard under heavy loads.

What is a fluid lever?

I do not know but I bet it bends easy and leaves a sticky mess in your hand!

Pinetr5000, I see this is your second post. I may or may not have seen the first one, however,  Welcome to CTOA.