stellar labs 7621 - Page 51

Stellar
®
Heavy-Duty Telescopic Crane Owner’s Manual | Page 47
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 ow valve in (7621 through 12630 models only).
Problem: Crane operates slowly.
Solutions:
• Make sure that the crane is receiving the recommended hydraulic ow to operate.
• Check the level of hydraulic uid in the reservoir. Add uid as needed.
• Check hydraulic uid temperature.
• Check to see if the valve bank orice is plugged. If so, replace the orice. 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.
Courtesy of CraneMarket.com