5.7 Failure diagnoisis & solutions
phenomeno
Possible reason
solution
No oil
Low oil level in oil tank
Add to specified level
output of oil
Suction pipe or screen is blocked
Clean oil line and oil tank. If the hydraulic
pump
foil is foul, replace it.
Bearing wear; damage of retainer and O ring
Replace the faulty parts
There is air in the oil pump.
Tighten the loosened connector on the
Low output
suction side
oil pressure
Add hydraulic oil to the tank.
of oil pump
Check oil seal.
Use the oil pump after bubbles in oil tank
disappear.
Hose on suction side twists or screen is
blocked, resulting in cavitation.
Adjust, replace or clean the screen.
Oil pump
Retighten every connector.
making a
noise
Use new hydraulic oil of viscosity suitable
Air is sucked from the loose connector on
suction side.
Cavitation is caused due to high viscosity of
hydraulic oil.
for running speed of oil pump
Examine the cause ofbubles and then take
There are bubbles in hydraulic oil.
proper measures.
Oil leakage Oil seal is damaged, 0 ring or sliding surface
Replace the faulty parts
of oil pump
of oil pump is worn.
Fork
Valve body and valve lever are worn, resulting
Replace the valve lever according to the
carriage
in big gap.
required gap.
descending
Valve lever is not centered
Keep the valve body in the middle.
obviously
Cylinder seal is out of order
Check and repair the oil cylinder.
when lifting
lever is in
Overload valve is worn or stuck by dirt.
Replace or clean the overload valve.
the middle
Reset spring is damaged or deformed
Replace the spring
There is dirt between valve body and valve
lever
Clean
Reset fails
Operation mechanism is stuck.
Adjust
Components at the reset position are
Reassmble and keep coaxial
misaligned
115
0 ring is damaged
Replace
Poor connector sealing at oil port
Check tightness and sealing at related
External
positions.
leakage
Seal plate is Loose
Clean the seal plate and retighten the bolts.
Lock nuts of safety valve and connecting bolts
Tighten
of valve plate are loose.
VI. Lifting
System
6.1 Technical data
type
C-shaped outer mast, L-shaped inner mast, two-stage rolling type
Roller size
(mm)
lloller of outer mast: 4.32
Combined roller of inner mast: 4.69
�ombined roller of fork carriage: 4.69
oiler of fork carriage: 4.71
Sider roller of outer mast: 1.
8
5
Lifting chain
LHl623 (2t-3t )
LHl634 (3.5t-4.0t)
Fork distance adjustment
Manual type
6.2 Overview
The lifting system consists of inner & outer mast, fork carriage, forks, cargo-holding carriage,
lifting cylinder, tilting cylinder and lifting chain, it is the operation mechanism of loading
and unloading work. The standard configuration for forklift is two-stage broad-vision mast. It can
optionally equipped with two-stage free lifting mast or three-stage free lifting mast.
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Ranko R55 Forklift
Operator's Maintenance Manual
Common Faults & Solutions
Ranko R55 Forklift
Operator's Maintenance Manual
Common Faults & Solutions
