ep ICE301B - Page 18

26
REV. 09/2020
27
REV. 09/2020
TROUBLESHOOTING TROUBLESHOOTING
3 3
Table 3.1 Troubleshooting of Common Faults (continued)
Fault Fault Symptom Probable Causes Troubleshooting
Lifting System
Failure
1. Slow Lifting of
Vehicle
• Overload
• Hydraulic pipeline leakage
• Valve failure:
• Gear pump wear, internal
leakage occurs
• Insu󰀩cient relief valve pressure
or blocked
1. Refer to the rated capacity
marked on the nameplate;
2. Check the pipe and hydraulic
components for oil leaks;
3. Wash or replace the valve
body
2. Slow Lowering of
Vehicle
• Solenoid valve blocking
• Valve body failure: throttle valve
failure or blocked
1. Wash or replace the solenoid
pool
2. Wash or replace the valve
body
3. Unstable Lifting /
Lowering of Vehicle
• Chain loosening;
• Poor lubrication between steel
channel and rollers;
• Improper adjustment of rollers, or
blocked.
1. Adjust the chain tension;
2. Check if the steel channel
grease is normal, clean and
relubricate steel channel and
rollers;
3. Adjust the side roller spacing
through roller screw; or
replace the roller.
4. Fork arm carrier or
mast tilt by itself.
• Tilt cylinder and ring abraded
excessively
• The hydraulic control valve spring
is inoperative.
1. Replace piston ring tilt
cylinder.
2. Replace it.
5. The fork arms carrier
moves up and down
sluggishly.
• Caused by piston jamming or
bent piston rod.
• Too much dirt is accumulated in
the cylinder.
1. Replace the faulty parts.
2. Strip it down and clean.
6. Forks are lifted or
lowered unsmooth.
• Carriage bracket assembly out of
adjustment.
• Insu󰀩cient clearance between
inner and outer masts or rollers
and mast.
• Biting foreign materials between
moving parts.
• Insu󰀩cient lubrication.
• Bent carriage bracket assembly.
1. Adjust clearance with thrust
metal and carriage side roller.
2. Adjust clearance with rollers.
3. Remove foreign materials.
4. Apply grease on contact sur-
faces of sliding parts.
5. Repair or replace.
* Under the circumstances of normal lifting and lowering, if failure occurs to any of other
hydraulic actions (forward/backward shifting, forward/backward tilting and left/right shifting),
perform troubleshooting to the corresponding control switch and its control circuit.
Table 3.1 Troubleshooting of Common Faults
Fault Fault Symptom Probable Causes Troubleshooting
Hydraulic
Failure
1. Noisy pump
• Insu󰀩cient oil;
• High viscosity of oil;
• Oil suction pipe air leak;
• Filters clogged by impurities;
• Hydraulic oil with foam;
1. Check the hydraulic oil level.
2. Replace the hydraulic oil.
3. Check the oil suction pipe.
4. Clean the oil inlet piping, re-
place the lter, if necessary.
5. See Fault 2.
2. Hydraulic oil with
foam
• Pump cavitation;
• There is water in the oil.
1. Check the amount of oil;
2. Check if the viscosity of hy-
draulic oil is normal;
3. Check the oil inlet piping for
air leaks;
4. Discharge and clean, and
replace with new hydraulic
oil.
3. Pump or oil
temperature is too
high
• Oil is too thin;
• Pump cavitation;
• Valve body internal relief.
1. Discharge and clean, and
add new hydraulic oil;
2. Check the oil inlet piping for
air leaks;
3. Replace the valve body.
4. Low System
Pressure
• Insu󰀩cient oil;
• Relief valve failur
• Pump wear, internal leakag
1. Check the hydraulic oil level;
2. See Fault 6;
3. Replace the gear pump.
5. On load, declined • Solenoid valve failure;
1. Check and clean the solenoid
valve spool.
2. Check the multi-way manual
valve and it installation.
6. Relief valve pressure
unstable or too low
• Pressure adjustment screw too
loose;
• Relief valve spring breakage or
deformation;
• Relief valve spool wear or
blocked.
1. Adjust to proper pressure
through hydraulic pressure
gauge.
2. Replace the relief valve.
3. Clean or replace the relief
valve.
* Carry out trouble shooting in accordance with the order listed in the table, it can help you quickly
identify problems and resolve accordingly.