I recently purchased two 628Ds, one 4wd and one 2wd. This is the first hydrostatic equipment I've ever owned and now trying to maintain.
The 4wd 628D wants to continue to move either forward or backwards once you take your foot off the gas, depending on which direction I was going. The left lifting arm doesn't want to go up, the brakes don't work near as good as the 2wd 628D, and when I turn the wheels all the way to the right the machine starts moving forwards.
I kind of don't know where to start other than making sure there is plenty of hydraulic fluid. Any help or guidance is appreciated.