Originally Posted by Morich
My thoughts on the fluid is to check the book and see if it matches what you have and then if it still might be a problem, top the fluid off to the top!
HWH pump fluid reservoirs have a dipstick built in to the screw in cap, but sometimes it's difficult to see the fluid on it. In any case, the correct fluid level is 1" from the top. No damage will ensue if you overfill the pump, the cap has a relief valve. It will, however, purge the excess fluid and make a big mess, staining your driveway, etc. (Don't ask how I know.) So make sure you put down some plastic and something absorbent like kitty litter before operating your pump after filling, even if you're sure you have it at the correct level. A couple of rags around the cap will help as well.
Here are a couple of helpful links. You'll need your exact model designation for the first one, which will ID what slide/jack system you have. The second one will lead you to manuals, procedures, etc.:
Tech Support, Manuals, Online Schools – General Information – HWH® Corporation