ZD28 hydraulic drive problem

Sea Dog said:

You should definitely test your fluid pressures before tearing it down. Kubota wants a small fortune for their test kit but I made mine for just a few dollars. Assuming you have determined where to hook up the charge pump pressure test from the WSM, remove that large Banjo bolt ( item #60 on the Hydraulic Delivery Pipe parts page). It can be drilled and tapped for 1/8" NPT pipe thread. Then all you will need is to adapt it to a hose and find a 1000 pound gauge. When finished with testing, install a 1/8" NPT plug. Checking the High Pressure pumps requires only hooking up a hose; the threads are standard tapered 1/4" pipe threads. It is pretty congested around those ports so I hoisted mine up and hooked up to the ports on the bottom. You will need a 5000 pound gauge for this.

Removing the Transaxle takes several hours to do but it's not terrible hard. You will need a cherry picker or hoist to remove it from the frame. Very awkward,

I thought my HST was toast on one side but pressure testing revealed that the HP Relief and Check valve was worn out and the spring was weak. I can just about assure you that if you take it to a dealer they will just install all new kit ($2K) and give you a $4K plus bill.

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