SANY LATIN AMERICA
7-107
SY195/205/215/225C9 Crawler Hydraulic Excavator
Troubleshooting
Shop Manual - June 2013
Trouble (2)
●
The arm drifts excessively.
Related information
●
Set working mode to (S) and fuel control dial at position (10) to
carry out troubleshooting.
Possible causes and standard value in normal state
Cause
Standard value in normal state/Remarks on troubleshooting
1
Failure of arm
cylinder
●
Stop the engine. Perform troubleshooting while the engine is running at
high idle.
Cut off the oil passage to the high-pressure side of the cylinder. Disconnect
the cylinder from the main valve. Measure the displacement of piston for 15
minutes after the cylinder becomes stable. If the measured value is greater
than 10 mm, it is deemed that cylinder has a defective seal. For more infor-
mation on the measuring procedure refer to "Testing and Adjusting", "Hy-
draulic Drift (Work Equipment) - Test".
2
Malfunction or
defective seal of
arm control valve
(relief valve and
makeup valve)
Relief valve or makeup valve of the arm control valve may be defective.
Check the valves directly.
●
The performance of seal can be judged by replacing it with another re-
lief valve or makeup valve. (Do not replace it with the boom-down relief
valve or makeup valve as their pressures are set differently.)
3
Failure of arm
retaining valve
Arm retaining valve or pilot valve may be worn or sluggish. Check the
valves.
4
Failure of arm
valve (spool)
Arm valve (spool) may be worn excessively. Check it directly.
Trouble (3)
●
The bucket drifts excessively.
Related information
●
Set working mode to (S) and fuel control dial at position (10) to
carry out troubleshooting.
Possible causes and standard value in nor-
mal state
Cause
Standard value in normal state/Remarks on troubleshooting
1
Failure of bucket
cylinder
●
Stop the engine. Perform troubleshooting while the engine is running
at high idle.
Bucket control lever
Leakage from bucket cylinder
Bucket-in relief
20 ml/min
2
Defective seal
of bucket control
valve (relief valve
and makeup valve)
Seal of relief valve or makeup valve of bucket control valve may be defec-
tive. Check it directly.
●
The performance of seal can be judged by replacing it with another
relief valve or makeup valve. (Do not replace it with the boom-down
relief valve or makeup valve as their pressures are set differently.)
3
Defective seal
of bucket control
valve (spool)
Seal of bucket control valve spool may be defective. Check it directly.
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