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OPERATION MANUAL
6.5 TROUBLESHOOTING
PROBLEM
POSSIBLE CAUSES
ACTION
Machine shudder on the
down stroke.
• Incorrect relief valve setting
• Re-adjust relief valve
Adjust the relief valve by unlocking
the hexagon head grub screw on
the side of the body of the valve.
Turn in a clockwise direction closing
the valve while cycling the machine.
Machine will not cut.
Check the blades for excessive
clearance or damage to the
cutting edges
• Reset or regrind as required.
1. Test the hydraulic pressure, if
insufficient; lower the top cutting
blade to its lowest position. Dis
connect the hydraulic hoses to the
cylinder and plug the hose. Test
the machine by operating the foot
pedal and inch up. If pressure is
obtained in both directions,
replace the hydraulic cylinder.
2. If pressure is not obtained in either
direction, plug the pump delivery
and recheck. If no pressure is
obtained, repair or replace both the
pump and the relief valve.
3. When pressure is obtained in one
direction only. Remove the main
ram cylinder and check for leaks by
operating on a test bench. If the
cylinder is not leaking, replace the
directional control valve.
Machine will not stop in the
neutral position.
• Check limit switch /relay
• Check directional control
valve
• Replace if necessary.
• Remove valve, check replace if
necessary
Oil leaking from cylinder
• Gland seal is damaged
• Change seal
Oil leaking from fittings
• Fittings are loose
• Tighten fittings
22/07/2019
Instructions Manual for SG-420 (S535)
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