Kubota 4520 PTO hydraulic question

[skunkelster]

I’ve been fixing up and rebuilding a Kubota 4520A. New seals, hoses, all pins unstuck after many years of neglect.

I tried out the hydraulics for the first time this week and blew up the PTO pump by cracking the casing. I suspect I’ve hooked up my hydraulic lines incorrectly from the pump to the valve manifold. So asking your help. Should the high pressure hose from pump be attached on left side of manifold (#1 in images) or right side (#2 in images)

I had it attached at #1 during testing and #2 attached to reservoir.

 

[ptsg]

#2 is the pressure In. This is where you connect the pressure line from the pump. The Hex part on top of it is the relief valve. Pressure In on hydraulic control valves is always on the relief valve side.

By connecting it backwards, you were bypassing the relief valve, therefore you none in the system. Once you tried to use a function you had a pressure spike with no where to go. The pump was the weak link this time, but blowing hoses or cracking the valve can also happen.