Lenco are electric. The trim tabs that are hydraulic used on Ranger tugs are Bennett tabs. The oil used for Bennett tabs is standard ATF Dextron II or III found at any Walmart, or auto parts store. The Ranger design in my opinion sucks using One pump to operate two systems. That is what you have so you must deal with it. The proper way to fill the pump reservoir is trim tabs fully retracted and hatch down. Fill the reservoir to the designated line on the pump reservoir. Do not over fill thinking that this will help your issue. It will probably cause an over flow and a mess. Fill to line then operate the trim tabs to full down position then retract do this a couple times to help remove any air out of the system. Now check the fluid level with the tabs fully retracted. Add if necessary. Now repeat this with engine deck hatch raise and lower several times. Take a break after each cycle so as to not over heat the pump motor. After a several cycles check fluid level with hatch in the down position. You should be ok from this point if there are no leaks. You must have the trim tabs retracted when lifting the deck hatch.