SANY LATIN AMERICA
7-106
SY195/205/215/225C9 Crawler Hydraulic Excavator
Troubleshooting
Shop Manual - June 2013
H-10 Work equipment drifts excessively
Trouble (1)
●
The boom drifts at excessive speed.
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 boom cylinder
●
Stop the engine. Perform troubleshooting while the engine is
running at high idle.
Charge the bucket with a load of approximate 1260 kg. 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 defec-
tive seal. For more information on the measuring procedure refer to
"Testing and Adjusting", "Hydraulic Drift (Work Equipment) - Test".
2
Failure of boom retain-
ing valve
Boom retaining valve or pilot valve may be worn or sluggish. Check
the valves.
3
Malfunction or defective
seal of boom control
valve (relief valve and
makeup valve)
The relief valve and the makeup valve in the boom control valve
may have a defective seal. Check the seals.
4
Failure of boom valve
spool
Spool of boom valve may be worn excessively. Check the spool.
https://www.tractormanualpdf.info/