I just bought a 1996? grasshopper 614 with the 44" deck with bagger/vacume. The hydros both seem kinda "tired" or slow going up hills. I believe the belt is tight enough so im going to change the fluid. My pumps dont seem to have filters like my 720k did just individual tanks on top of the pumps. Their both really low on fluid and awful dirty so i want to change the fluid. Question is and i cant find anything specific on 614s what can i put in that i can buy locally without having to drive an hour do our closest hopper dealer? Will any hydro fluid work? Ive seen some can take just a synthetic motor oil? Will that work on my application? Thanks for replies!!!