Komatsu PC58UU-3 User Manual

TROUBLESHOOTING H-7
PC58UU-3
20-519
1
a) Arm IN speed or power is low
★
When measuring the arm IN relief pressure, reset the interference prevention system.
★
When the arm speed is low, if the result of troubleshooting No. 1 is [NO], take actions against the relief
pressure and carry out troubleshooting No. 2.
H-7 Arm speed or power is low (Other work equipment is normal)
Cause Remedy
1
• 26.5
+1.0
- 0.5
MPa
{265
+10
-5
kg/cm²}
• Run engine at full throttle
Is arm IN relief pressure normal?
No
Yes
2
• 2.45 MPa {25 kg/cm²}
• Run engine at full throttle
Is EPC valve output pressure normal
(at PPC pressure inlet of control
valve?
No
Yes
3
Does control valve spool move
smoothly?
No
Defective operation of con-
trol valve spool
Repair or
replace
Yes
4
Does pressure compensation valve
move smoothly?
No
Defective pressure compen-
sation valve
Repair or
replace
Yes
Defective arm cylinder pack-
ing
Repair or
replace
5
• 26.5
+1.0
- 0.5
MPa
{265
+10
-5
kg/cm²}
• Run engine at full throttle
Is arm OUT relief pressure normal?
No
Defective centralized safety
valve
Replace
Yes
Defective suction valve (Arm
IN side)
Repair or
replace
6
(RAISE boom and move arm
IN)
When PPC hose of control valve is
replaced with boom RAISE hose, is
trouble repaired? (Return hose imme-
diately after checking.)
No
Yes
7
When arm is moved in while swing-
ing, is condition normal?
No
Go to troubleshooting No. 3 —
Yes
Defective seats of swing
brake circuit check valve and
swing PPC slow return valve
Repair or
replace
8
• 2.94
+ 0.5
- 0.1
MPa
{30
+ 5
- 1
kg/cm²}
• Run engine at full throttle
Are PPC pressure inlet of solenoid
valve and PPC valve output pressure
normal?
No
Defective arm IN PPC valve
Repair or
replace
Yes
Defective arm IN EPC valve
Repair or
replace

Komatsu PC58UU-3 Specifications

General

Brand	Komatsu
Model	PC58UU-3
Category	Construction Equipment
Language	English