oliver 1850 HELP!!!

Took my oliver 1850 about 5 miles mostly in 5th or 6th direcet drive to cut hay. Some time between point A and B it started leaking hyd oil. I got to my field and just as i entered the field I noticed smoke from the hydraulics under the seat. i shut down the tractor and opened all cab doors and windows. got out and found that i had a significant hydraulic leak on the side with the hydraulic levers. it was so hot that when i sprinkled a tad bit of water on it the water imediatly sizzled and boiled off!!! after a few minutes i took of the hydraulic fluid dipstick and it was bone dry! but there was such a mess it was hard to tell where it leak came from i think it was where the remote levers shaft enters the valve. I got some oil and filled it up again. at no point did i use any of my hydraulic remotes or the lift. I was in road gear. by this point it was to dark to inspect further. so here i am. what Happened? any ideas on were to start looking tomorrow????? im totally lost. and is it safe to drive if i keep the hyd fluid full and go slow to get home???? or does it need to be trailered? also where do i find parts for the valves ?? if thats what it is? also it seems that when i try to lower my moco (tried to after refilling hyd fluid )(single acting cyl )the hyd system lifts it back up imediatly after i take my hand off the lever. it was setup for a sing acting cylinder. it seems as if the pump still pressureizing the lines if that makes any senesce ?????????????? please help.

Sounds as though the 3pt. hitch was all the way up and did not have any free travel causing the relief valve to blow continuously. Heats the hydraulic system in a hurry. Back out the 3/4 head cap screw just above the floor board 3 revolutions, on the R.H. side just behind where your heel would normally be, and read your operators manual on single acting cylinders, disable the 3 point hitch.

That wouldn't make it leak though. There's a seal and o-ring on the shaft. I'll find the schematic.

Here's the schematics. The first one is the levers. Number 41 is a seal. I can't imagine enough pressure to let that much oil out of that one that quick.

The second one is the cover. 51 and 52 are tubes and O-rings. If memory serves me right there are six of those tubes and 12 O-rings? If one of those blew out and then the oil blew through the gasket,it would likely dump a lot in a hurry.

II traced back my route I took to the field. And about 1 mile from field I se where I started leaking oil and every where I pulled over to let cars by there is a small puddle . So I must have lost a seal some where and lost all my hyd oil. Also I noticed I did have 3pt arms all the way up if that makes a difference. The hyd where working fine before I left. Ill go back over the in a while to better asses the situation. Any thoughts on what to look for. Thank you for the help so far.

Had this happen on my 2050 once. My hydraulic lever was stuck and I hadn't noticed it. Put it back in the neutral position and everything was fine. That was a relief.

I'm drawing a blank unless an o-ring is blown on one of those tubes. I had my 1850 and 1550 both apart last year and rebuilt the cylinder in the 3 point on both. I changed all of those O-rings and the seal on that shaft in both tractors while I had them apart. There's an o-ring on that shaft too if memory serves me right.