I bought a used, early 1845c. PIN number is JAF0042XXX. I am hoping to service it. In the manual I notice that the HTO additive for the hydraulics is not needed for PIN numbers prior to JAF0067438. I don't know the history of this machine and what has/has not been replaced. Should I just skip the HTO additive, or should I add some just in case something was changed out along the way? What would you do? Thanks.
I thought all 1800 series machines required HTO, but apparently not. Personally I would add it, its relatively cheap.
Your machine does not need the HTO. Just use and good 10W30 engine oil. The later machines need the HTO to provide lubrication inside the gerator drive motors. The early machine like your have an axial piston motor which will work fine with just 10W30. You also have a planetary gearbox between the drive motor and the chainbox so be sure to service it and refill with 80/90.