Machine Cannot Be Steered Easily Or Steering Power Is Low - Komatsu PC130-8 Shop Manual

SEN04124-00
H-18 Machine cannot be steered easily or steering power is low
Trouble

• Machine cannot be steered easily or steering power is low.

Related
• Conduct the troubleshooting in working mode P.
information
Malfunction of travel PPC
1
valve
Malfunction of pump merge-
2
divider valve
Malfunction of travel junction
3
solenoid valve
Possible causes
and standard
value in normal
Malfunction of hydraulic
state
4
pump (check valve)
Malfunction of hydraulic
5
pump (shuttle valve)
Malfunction of pump merge-
6
divider valve
Malfunction of travel junction
7
valve
Malfunction of travel control
8
lever (spool)
Malfunction of travel control
9 lever (pressure compensa-
tion valve)
Malfunction of travel control
10
lever (suction valve)
Malfunction of travel motor
11
(safety and check valve)
20
Cause Standard value in normal state/Remarks on troubleshooting
a
In NEUTRAL on both sides
a
a
The check valve of the hydraulic pump may have a malfunction or
its sealing may be defective. Check it directly.
The shuttle valve of the hydraulic pump may have a malfunction or
its sealing may be defective. Check it directly.
The pump merge-divider valve may have a malfunction. Check it
directly.
The travel junction valve may have a malfunction. Check it directly.
The spool of the travel control lever may have a malfunction.
Check it directly.
The pressure compensation valve of the travel control lever may
have a malfunction. Check it directly.
The suction valve of the travel control lever may have a malfunc-
tion. Check it directly.
The safety and check valve of the travel motor may have a mal-
function. Check it directly. (It may be checked by exchanging the
front and rear motors or the right and left motors and checking
change of the phenomenon.)
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Travel lever
Operated on either side
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Travel lever
All levers in NEUTRAL
Position for travel only
(On either or both sides)
Keep the engine stopped for the preparations, and keep it
running at high idle during the troubleshooting.
Travel lever
All levers in NEUTRAL
Position for travel only on
either side
40 Troubleshooting
PPC valve output pressure
0 MPa {0 kg/cm }
2
Above 2.7 MPa
{Above 28 kg/cm }
2
Solenoid valve output pressure
0 MPa {0 kg/cm }
2
2.84 – 3.43 MPa
{29 – 35 kg/cm }
2
Solenoid valve output pressure
0 MPa {0 kg/cm }
2
2.84 – 3.43 MPa
{29 – 35 kg/cm }
2
PC130-8
1