jcb JS 200 Series, Руководство по обслуживанию

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78 - 1
Section E
Hydraulics
9803/6400
Section E
78 - 1
Issue 1
Hydraulic Rams
Trouble Shooting
Hydraulic ram trouble and its remedies.
It is not easy to find the part causing the trouble. In the chart below, possible problems are listed. Repair is difficult so refer to
the estimated cause and treatment listed in the chart. In the chart, the general phenomenon, estimated causes and treatment
are shown. However, machine trouble is most often caused, not by just one faulty part, but its relationship with other parts. Not
all of the possible causes and treatments are listed in the chart below, therefore, it may be necessary for the person responsible
for repairs to make further investigations to find the cause of the trouble.
Item Symptoms
1 Oil leakage from piston rod sliding part
2 Oil leakage from cylinder head meeting part
3 Oil leakage from pipe and cylinder tube welded part
4 Faulty operation
Item Symptoms Related Parts Trouble Treatment
On the sliding surface, there are 1. Use an oil stone and remove the scratch
scratches and rust that can be and make the sliding surface smooth.
felt by the fingernail. (Less than 1.5 S). If oil leakage
continues even though the rod surface is
made smooth, the scratch may cause
damage to the U-ring and other seals, so
disassemble and inspect.
Piston rod 2. If the scratches and rust cover such a
wide area that they cannot be repaired
by an oil stone, replace the piston rod
and U-ring, wiper ring and seals and the
piston rod bearing member.
Piston rod The plating is peeling. Re-plate or replace the piston rod.
1 sliding part Also inspect the seal and piston rod
oil leakage bearing member and replace if damaged.
Foreign matter is biting into the Remove foreign matter.
inner and outer surfaces of If there is damage to packing, replace it.
the packing.
There is a scratch on the inner Replace.
and outer surface of the packing.
Rod packing The lip and groove parts are Possibly due to burning caused by
(Buffer ring, locally carbonized (burned). adiabatic compression from air remaining
U-ring) inside the ram. After replacing the
packing, first operating the ram at
low-pressure, low speed to sufficiently
bleed the air.