SANY LATIN AMERICA
7-104
SY195/205/215/225C9 Crawler Hydraulic Excavator
Troubleshooting
Shop Manual - June 2013
H-8 Bucket speed slow
Trouble
●
The bucket moves slowly.
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
Malfunction of right
pilot valve (bucket
circuit)
●
Stop the engine. Perform troubleshooting while the engine is running
at high idle.
Bucket control lever
Pilot valve output pressure
"NEUTRAL"
0 {0}
Bucket CURL or Bucket DUMP
≥
3.5MPa
{36 kg/cm²}
2
Failure of pressure
sensor
●
Stop the engine. Perform troubleshooting while the engine is running
at high idle.
Check the pressure sensor by replacing it with a new one.
3
Malfunction of
bucket control valve
(spool)
Spool of bucket control valve may have malfunction. Check it directly.
4
Malfunction or
defective seal of
bucket control valve
(relief valve and
makeup valve)
Relief valve and makeup valve in bucket control valve may have mal-
function or defective seal. Check the valves directly.
5
Failure of bucket
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 cylin-
der from the main valve. Measure the displacement of piston for 15 min-
utes 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
information on the measuring procedure refer to "Testing and Adjusting",
"Hydraulic Drift (Work Equipment) - Test".
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