Stellar
®
Heavy-Duty Telescopic Crane Owner’s Manual | Page 29
Customer Service for instructions.
• Make sure the proportional valve is receiving 12V power when fully engaging the
transmitter trigger. If there is not 12V power while pulling the trigger, check for loose
connections inside the transmitter or replace the handle trigger assembly. If the
proportional valve is receiving 12 volts, loosen the solenoid holding nut and check to
see if the solenoid coil is magnetizing. If no polarity is present, replace the coil. If coil is
magnetizing, remove the stem valve, thoroughly clean, lubricate, and reinstall the valve.
Problem: Winch “Up”, Main Cylinder “Down”, and Extension Cylinder “Out” are the only
functions that don’t operate.
Solutions:
• Make sure that the anti-two block weight and chain on the end of the boom are straight
so they slide easily along the wire rope cable.
• Make sure that the limit switch is working properly. Disconnect the two wires connected
to the limit switch and tie them together. If all functions operate, replace the limit switch.
• Make sure that the cord for the cord reel is undamaged. Check the continuity of
the cord. Disconnect the cord reel from the crane harness and bypass the harness
connection. If the crane operates properly, replace cord reel.
Problem: Cylinder drifts outward or downward.
Solutions:
• Check to see if there is air in the hydraulic system. Operate all cylinders connected to
the hydraulic system. Start with the extension cylinder, then operate the main boom,
winch, rotation, and ending with the hydraulic stabilizers, if installed. When operating,
extend each cylinder halfway out, retract all the way in, and then extend until the
cylinder rod is at the end of its stroke. Operate cylinders slowly so air is pushed thru the
system to the reservoir. Repeat this cycle 2-3 times.
• Make sure the holding valves are operating properly. Note: Before performing any
maintenance on hydraulic components, relieve hydraulic oil pressure from all hydraulic
circuits. Remove, clean, and then inspect each holding valve. When removing a
holding valve, always relieve the pressure inside the cylinder by loosening jam nut of
the holding valve and turning set screw inward/clockwise. Count the number of turns
until the set screw is seated. When reinstalling the holding valve, make sure the valve is
reset by turning the set screw the number of turns it took to relieve the pressure. Finish by
tightening the jam nut.
• Check the cylinder rod for scratches. If a scratch is located on the cylinder rod,
hydraulic uid can pass thru and cause a loss of pressure. Replace cylinder rod or
cylinder.
• Check to see if the piston seals are damaged. If they show signs of damage, install a
new cylinder seal kit.
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