H-24 One Of Tracks Does Not Run - Komatsu PC88MR-10 Shop Manual

H-24 One of tracks does not run

Failure One of tracks does not run.
Perform all troubleshooting with working mode set in power (P) mode.
Travel PPC pressure can be checked with monitoring function. (monitoring code: 07102,
Related
07103, 07104, 07105)
information
Pump pressure can be checked with monitoring function. (monitoring code: 01100)
No. Cause
Malfunction of R.H.
1
travel PPC valve
Malfunction of L.H.
2
travel PPC valve
Malfunction of R.H.
travel control valve
3
(spool)
Malfunction of L.H.
travel control valve
4
(spool)
Malfunction of R.H.
travel control valve
5
(suction valve)
Malfunction of L.H.
travel control valve
6
(suction valve)
Defective R.H. travel
7
motor (safety valve)
Defective L.H. travel
8
motor (safety valve)
Defective R.H. travel
9
motor (check valve)
Defective L.H. travel
10
motor (check valve)
PC88MR-10
Troubleshooting of hydraulic and mechanical system (H-
(PC88MR-BG1-400-A-Z0-A)
Procedure, measuring location, criteria, and remarks
a Be ready with engine stopped, then perform troubleshooting with engine at
high idle.
R.H. travel lever
PPC valve output
pressure
R.H. travel lever
a Be ready with engine stopped, then perform troubleshooting with engine at
high idle.
L.H. travel lever
PPC valve output
pressure
L.H. travel lever
If no failure is found by check on cause (1) and one track does not run when
travel control lever is operated with pump pressure at approx. 4 MPa, check
whether spool is stuck near NEUTRAL position.
If no failure is found by check on cause (2) and one track does not run when
travel control lever is operated with pump pressure at approx. 4 MPa, check
whether spool is stuck near NEUTRAL position.
When R.H. travel lever is operated, if R.H. track does not run because of low
pump pressure, check suction valve.
When L.H. travel lever is operated, if L.H. track does not run because of low
pump pressure, check suction valve.
a Be ready with engine stopped, then perform troubleshooting with engine at
high idle.
Travel relief
pressure hydraulic relief
If relief pressures of travel FORWARD and REVERSE are unusual to the
same degree, sealing of safety valve may be defective.
Interchange safety valves of L.H. and R.H. travel motors, and check whether
failure symptom changes.
a Be ready with engine stopped, then perform troubleshooting with engine at
high idle.
Travel relief
pressure hydraulic relief
If relief pressures of travel FORWARD and REVERSE are unusual to the
same degree, sealing of safety valve may be defective.
Interchange safety valves of L.H. and R.H. travel motors, and check whether
failure symptom changes.
If safety valve is found to be normal in checks on cause (7), sealing of check
valve may be defective.
Interchange check valves on FORWARD and REVERSE sides of same travel
motor, and check whether failure symptom changes.
If safety valve is found to be normal in checks on cause (8), sealing of check
valve may be defective.
Interchange check valves on FORWARD and REVERSE sides of same travel
motor, and check whether failure symptom changes.
NEUTRAL
FORWARD and
REVERSE
NEUTRAL
FORWARD and
REVERSE
R.H. travel
FORWARD and
REVERSE
L.H. travel
FORWARD and
REVERSE
40 Troubleshooting
mode)
0 MPa {0 kg/cm 2 }
Min. 2.65 MPa
{Min. 27 kg/cm 2 }
0 MPa {0 kg/cm }
2
Min. 2.65 MPa
{Min. 27 kg/cm 2 }
26.5 ± 1.5 MPa
{270 ± 15 kg/cm 2 }
26.5 ± 1.5 MPa
{270 ± 15 kg/cm 2 }
40-501