Stellar® Heavy-Duty Crane Owner’s Manual
Now operate the winch. If the brake still does
not hold, contact Customer Service at Stellar.
Problem: Winch will not hold load.
Solutions:
• Make sure that the object being lifted does not
exceed the rated capacity of the winch. Refer
to the capacity chart. If the object is within the
rated capacity, reposition the truck and try to
lift the object without using the crane boom
extensions.
• Make sure that the relief valve on the winch is
set correctly. Readjust the relief valve if
necessary.
Problem: Crane only operates at full speed.
Solutions:
• Check to see if there is 12V power constantly
going to the proportional valve. If 12 volts are
showing up at the proportional valve without
pulling on the transmitter trigger, the
handle/trigger assembly may be defective. If 8
volts are showing at the proportional valve, it is
possible that the valve is stuck open and will
not close. Remove the valve, clean it
thoroughly and reinstall. Do not over tighten. If
the problem persists, replace the proportional
valve.
• Check to see if the manual override on the
proportional valve is turned out. Turn the
manual override on the flow valve in.
Problem: Crane operates slowly.
Solutions:
• Make sure that the crane is receiving the
recommended hydraulic flow to operate.
• Check the level of hydraulic fluid in the
reservoir. Add fluid as needed.
• Check hydraulic fluid temperature.
• Check to see if the valve bank orifice is
plugged. If so, replace the orifice. Call Stellar
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
fluid 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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