SUNWARD SWE20F 2019, Operation & Maintenance Manual, Page: 90 / 104

88
Malfunctions and solutions
Malfunction Reasons Solutions
Noisy hydraulic pump and
vibratory pipeline
1
．
Hydraulic malfunction.
2
．
Air bubble in hydraulic
system.
3
．
Aging hydraulic oil,
degenerative oil mixed with
moisture, wrong brand and
specification produce
bubble.
4
．
Low hydraulic oil
temperature and high
viscidity of hydraulic oil.
1
．
Consult with your
dealer.
2
．
Check whether air
leakage at oil pump inlet
pipeline.
3
．
Replace oil.
4
．
Run engine in low revs
and then warm up the
engine.
Control levers don’t work
or work slowly.
1
．
The machine is out of use
for a long time, air
separates from oil and
floats in pilot control
pipeline and hydraulic
cylinder,etc.
2
．
No pressure or exceeding
pressure in pilot system.
3
．
Low hydraulic oil
temperature and high
viscidity of hydraulic oil
4
．
Hydraulic pump
malfunction.
5
．
Main safety relief valve
malfunction
1
．
Operate control levers
for several times.
2
．
Check hydraulic control
system, low-pressure
relief valve, and gear
pump.
3
．
Warm up machine.
4
．
Consult with your
dealer.
5
．
Consult with your
dealer.
A cylinder doesn’t work
or work slowly.
1
．
Corresponding pilot valve
malfunction
2
．
Corresponding
commutator valve
malfunction
3
．
Corresponding overload
valve malfunction
4
．
Hydraulic cylinder pole
damaged
5
．
Hydraulic cylinder interior
seals damaged
1
．
Repair
2
．
Consult with your dealer
3
．
Consult with your dealer
4
．
Consult with your dealer
5
．
Replace oil seals