[wingnut60]

I would think the first thing to try would be some dry silicone grease, sprayed generously on the rack teeth--don't use reg grease. If that doesn't help, maybe something on the rack is out of line/binding. To see the operation of the slides, it will be necessary to cut into the chloroplast cover in two places--each cut in line with the slide rack. If you do this, make the cut a 3-sided piece that will hang down from the front-facing side. Once you find the problem, you can easily place the cut portion back with screws/gorilla tape or such.
If they are still the same as my former '05--the slide ram is at the rear of the DS and at the front or the ODS.
Use a turkey basting bulb to fill the reservoir...don't try to pour out of the oil container, it is a tight fit in there.
As porthole said--1" from top of tank (not top of fill neck) when all slides are in and all jacks are up when hitched.