I do have the OLIVER shop manual for the 7600/7800 but the hydro section refers more to the 7800 hydro that has the charge pump mounted to the hydro unit.The 8600/8800 WHITE shop manual seems to look more like hydro unit in the 7600. I also have a complete transmission with the hydro unit out of a Quad 5 combine that worked fine that we salvaged after it caught fire. But there again that unit looks like the 7800 not the 7600. I don't know but there maybe some internal parts that could work on the 7600.I just use this machine for small grain &amp; have a 8700 for corn &amp; beans so I have some time to get the 7600 fixed.Thanks to all that respond ! John I could also use the charging info for the 12 volt pos ground system like the guy with the 1800-c charging problem.our 1900 has the same issue I said I think its the voltage reg . but its better to trouble shot it before a guy just starts throwing parts at it.