Lift All tank oil level ?? Super M with tank under gas tank.

My hydraulic reservoir drips around where the shaft comes out of it on the right side of it.I recently took it apart to clean the tank out and I installed a new o ring,Still dripping slightly.Shaft is just SLIGHTLY sloppy in the bore.(I wonder if I should have took the time and had that hole oversized and installed a bushing????)
But what I was wondering where IS the oil level is supposed to be anyway??? Is it supposed to be BELOW that shaft ?Have I been overfilling it all this time? It looks to be kinda hard to put a dipstick on this one because of the 45 deg elbow right at the tank?(I know they make a stick for the "belly"pumps.)
My hydraulic system either has to run TWO 3x8 cylinders on my 3 point hitch or ONE 3x8 cylinder on my plow or disk.NEVER all at the same time.
I do not wanna EVER run my live pump low!!!(I know they cost from $600.00 to $800.00 bucks !!!

That plug is horizontal vs the 400 plug which is tilted down. The 400 plug has a dipstick.

The fill plug is at the same level as the lever shaft that enters the Liftall reservoir. Considering that there is no vent on the reservoir, is there any wonder that some oil leaks past the O-ring when it is hot and expanded?

My advice is to not fill the reservoir to the assumed fill level. Lower it by 1/2" to 1". If your three cylinders are double acting, you will never be short on hydraulic fluid unless it is leaking somewhere else.

However before the PS starts going away the live pump begins making buzzing and gurgling noises - especially on a cold startup. When it does this I add about 2 quarts of hydraulic oil to the reservoir. The system will now be good for several more months.

Don't know if it is right way to set the fluid level. But I've been running the tractor this way for 20+ years with no hydraulic problems whatsoever.