Our 1941 1 1/2 Ton Dodge Truck has a twin cylinder Heil hydraulic hoist that has the pump and reservoir built in (see pic) and it will not go high enough. I think it only goes to about 30 degrees. Worse I blocked it up to work on the hoist and the block is now stuck because it will not go any higher so I can remove the block! LOL! Hoping it just needs fluid but no idea how to add, bleed, type of oil, etc.???? I suspect oil is added thru the big brass plugs on each cylinder. Maybe one of the lower plugs is removed and you watch to see when oil comes out?? This is a Heil model no 3S26. Thx!!