Cub Cadet U-Channel Beam Style - Manual (Page 27)

Hydrualic Diagnosis
23
H. Extend the cylinder fully using the log splitter control
valve.
• As the ram reaches the end of its travel, pressure
will build until the relief valve opens.
• Record the maximum pressure reached on the
worksheet.
NOTE: If the needle on the pressure gauge moved too
fast to get a good reading on the extension stroke,
adjust the needle valve while retracting the cylin-
der to slow down the rate that the pressure builds.
Repeat step H.
I. Record the rated relief valve pressure from the relief
valve settings chart on to the worksheet.
NOTE: The relief valve is not adjustable. If the reading is more than 100 PSI of what is listed in the chart,
replace the valve. If the reading is more than 100 PSI lower than what is listed in the chart, it could be
a bad valve or a cylinder leaking internally.
5. Cylinder blow-by test:
A. Hold the control valve in the extend position until the ram stops moving.
B. Record the flow reading after the ram stops moving.
NOTE: Pressure decay when the ram is fully extended indicates that the cylinder/piston seals are not working.
NOTE: Seal kits are available to repair leaking cylinders. If the cylinder has mechanical damage, it must be
replaced.
What to do about failures
1. If a pump is bad:
• Replace the pump. The pump is not serviceable.
• If the pump failed because of an external cause, identify and eliminate the cause.
NOTE: Any disassembly of the pump WILL VOID THE WARRANTY. Do not take the pump apart if the repair is
warrantable.
2. If the control valve is bad:
• If the repair is warrantable, replace the control valve.
NOTE: Any disassembly of the control valve WILL VOID THE WARRANTY. Do not take the control valve apart
if the repair is warrantable.
3. If the cylinder is bad:
• If the cylinder is leaking at a seal, it may be repaired using a cylinder rebuild kit.
• If the cylinder is leaking at a welded seam, or has mechanical damage such as a bent shaft, replace the
cylinder.
Relief Valve Settings
Valve part
number
Tonnage
Relief valve
setting
+ 100 PSI
718-04706 27 and 33 3400 PSI
(234 bar)
718-04739 21 2700 PSI
(186 bar)
718-04740 25 3200 PSI
(221 bar)