"it works a lot faster than the belly pump. Curious why/how it pumps so fast."
Short answer.,.. because it displaces more cubic inches of oil per revolution of the PTO shaft than the than the pathetic little OEM hydraulic pump!
If no one comes forward with a spare copy of the manual, there's on on fleabay, # 350738562172.
Or, see the rather awkward scan at the link below.