Speed Or Power Of Bucket Is Low - Komatsu Galeo PC800-8 Shop Manual

40 Troubleshooting
H-7 Speed or power of bucket is low
Failure

• Speed or power of bucket is low

phenomenon
• Check that the speeds of the other work equipment, travel, and swing are normal.
(If they are abnormal, carry out the related troubleshooting.)
Relative • Check that the machine does not deviate.
information (If the machine deviates, carry out the related troubleshooting.)
• Carry out all the troubleshooting in working mode P.
• Before carrying out troubleshooting, check that electric circuit related to bucket control is normal.
Malfunction of right PPC
1
valve (bucket circuit)
Malfunction of bucket con-
2
trol valve (spool)
Possible causes
and standard
value in normal
Malfunction of bucket con-
state
3 trol valve
(safety & suction valve)
Defective bucket control
4
valve (body)
Defective seal of bucket
5
cylinder
PC800, 850-8
Cause Standard value in normalcy and references for troubleshooting
aPrepare with the engine stopped, then carry out troubleshooting with
the engine at high idle.
R.H. work equipment control lever
Since the spool of the bucket control valve (Lo, Hi) may have a malfunc-
tion, check it directly.
Since the safety & suction valve of the bucket control valve (Lo, Hi) may
have a malfunction, check it directly. (The safety & suction valve may be
checked by replacing it with one of another work equipment circuit. After
checking, however, be sure to return the safety & suction valve since its
set pressure and structure are different from the others.)
Since the body of the bucket control valve (Lo, Hi) may have a malfunc-
tion, check it directly.
aPrepare with the engine stopped, then carry out troubleshooting with
the engine at high idle.
R.H. work equipment control lever
Relieved in bucket CURL position
(bucket)
Bucket CURL, DUMP
Full stroke
(bucket)
SEN00794-02
PPC valve output pressure
+0.8
2.9 MPa
–0.2
+8
{30 kg/cm 2 }
–2
Leakage from cylinder
Max. 20 cc/min
17