Autoquip PDQ DOCK LIFT - Manual (Page 34)

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PROBLEM POSSIBLE CAUSE AND SOLUTION
Lift will not lower. • The down solenoid may be malfunctioning.
• The maintenance device could be installed.
• The structural members may be in a bind.
• The tubing or hose is obstructed or broken. Check
for obstruction in the line.
• The return filter may be clogged.
• The velocity fuse may be locked. Do not attempt to
remove the velocity fuse. The following steps
should be followed:
1. Remove the load from the lift. Inspect all fittings,
hoses, and other hydraulic components for leads or
damage.
2. If no leak or damage is noticed, attempt to
pressurize the lifting cylinder by depressing the “UP”
button on the controller for a few seconds.
Immediately up releasing the “UP” button, depress
the “DOWN” button. If the lift starts to lower, continue
pressing the “DOWN” button until the lift is in the fully
lowered position.
3. If the lift does not lower after trying Step 2, wait
approximately 10 – 15 minutes for the pressure in the
hydraulic system to equalize. Then, depress the
“DOWN” button until the lift is in the fully lowered
position.
4. Once the lift is in the fully lowered position, bleed
the air from the hydraulic system by depressing the
“DOWN” button. Hold the “DOWN” button for
approximately 60 seconds. This step may need to be
repeated several times to fully remove the air in the
system by raising the lift to 50% of its rated travel
then lowering. Bleed air from the bleeder screws on
top of the cylinders.
• Should the above steps not correct the problem,
contact Autoquip to obtain instruction for further
action.
TROUBLESHOOTING ANALYSIS