There is no good way to fill the tank without using the "level indicator" (bong/light) working.
I would make a dipstick (like a pipe cleaner or stiff wire) and find the height of the oil level now. Then see where the tank fluid level screws into the side of the tank and make sure the oil level is above that.
I'm not sure what/where the level sensor is located - but I assume it would be mounted/screwed into the side of the oil tank around the 2/3rds full height.
You can add oil with one of those cheap plastic hand pumps sold at most auto parts stores.
Automatic JII Leveling System
RVA Company / www.rvajacks.com
©2005 RVA Company All Rights Reserved
Pages 5 of 11
2. Learn the sounds of a normal pump as jacks extend, the relief valve as jacks extend fully, and the gurgling sound of the pump when the unit is low on fluid. If necessary to add fluid, use regular Automatic Transmission Fluid (Dexron III).
3. If it is necessary to fill with additional fluid, start by extending any jack 6” from fully retracted position (other jacks should be fully retracted). Unscrew reservoir cap from the top of the pump, fill with fluid until red light and bong turn off, then stop adding fluid and replace the cap.