Hydraulic pump questions

Probably too late, but you never dead head a hydraulic pump. It will build pressure until the case fails, and that takes next to no time at all. The risk of injury from high pressure oil or fractured pump parts is not to be taken lightly.

Some gear pumps are not reversible.

Bucket to bucket using an electric drill to turn the shaft. The drill will stall if the oil can't flow and that'll prevent any damage.

Pumps don't make pressure, they move fluid. They are designed to withstand the pressure created when the actuator does its work up to their pressure rating.

Pictures may help. If the manufacturers plate is still attached to the pump, or numbers are cast into the body, then you can go to the source with no guessing. From the limited view of your current pics, that pump looks to have a built in relief valve. If that is the case, it will only work in one direction.

The symbol on the end plate says that it is a unidirectional pump and the cavity design bears that out.

Contact these folk for a definitive answer. The pics may help.

http://www.casappa.com/eng/02products/custom_design/special.htm

Click "Contacts" at the top of the page and "USA" on the left of the next page. They may be close enough that you can take it over and talk to them in person. You can get more info in person than with an email if you talk nice-nice.