H-22 Machine Is Hard To Steer Or Travel Power Is Low - Komatsu PC88MR-10 Shop Manual

H-22 Machine is hard to steer or travel power is low

Machine is hard to steer or travel power is low.
Failure
Perform all troubleshooting with working mode set in power (P) mode.
If failure codes are displayed, perform troubleshooting for them first. (DW91KA, DW91KB)
Related
Travel PPC pressure can be checked with monitoring function. (monitoring code: 07102,
information
07103, 07104, 07105)
No. Cause
Malfunction of R.H.
1
travel PPC valve
Malfunction of L.H.
2
travel PPC valve
Malfunction of pump
3 merge-divider solenoid
valve
Malfunction of travel
4
junction valve (spool)
Malfunction of hydraulic
5
pump (check valve)
Malfunction of hydraulic
6
pump (shuttle valve)
Malfunction of merge-
7
divider main spool
Malfunction of R.H.
travel control valve
8
(spool)
Malfunction of L.H.
travel control valve
9
(spool)
PC88MR-10
Troubleshooting of hydraulic and mechanical system (H-
Procedure, measuring location, criteria, and remarks
a Be ready with engine stopped, then perform troubleshooting with engine at
high idle.
R.H. travel PPC
valve output
R.H. travel lever
pressure
a Be ready with engine stopped, then perform troubleshooting with engine at
high idle.
L.H. travel PPC
valve output
L.H. travel lever
pressure
a Be ready with engine stopped, then perform troubleshooting with engine at
high idle.
Travel lever in the neutral position
Output pressure of
solenoid valve
Single operation of travel (either
a Release remaining pressure from hydraulic tank and piping, and then
perform troubleshooting with engine stopped.
Check for stuck or seized travel junction valve spool in merge-divider
valve body.
(Spool must move smoothly and must not be caught.)
Remove travel junction valve spool from valve body and check it for
defects and dirt.
Take care not to let foreign matter enter valve when re-installing spool.
The check valve of the hydraulic pump may malfunction or its sealing may be
defective. Check it.
The shuttle valve of the hydraulic pump may malfunction or its sealing may be
defective. Check it.
a Release remaining pressure from hydraulic tank and piping, and then
perform troubleshooting with engine stopped.
Check for stuck or seized main spool in merge-divider valve body.
(Spool must move smoothly and must not be caught.)
Remove main spool from valve body and check it for defects and dirt.
Take care not to let foreign matter enter valve when re-installing spool.
a Release remaining pressure from hydraulic tank and piping, and then
perform troubleshooting with engine stopped.
Check for stuck or seized travel spool in control valve body.
(Spool must move smoothly and must not be caught.)
Remove travel spool from valve body and check it for defects and dirt.
Take care not to let foreign matter enter valve when re-installing spool.
a Release remaining pressure from hydraulic tank and piping, and then
perform troubleshooting with engine stopped.
Check for stuck or seized travel spool in control valve body.
(Spool must move smoothly and must not be caught.)
Remove travel spool from valve body and check it for defects and dirt.
40 Troubleshooting
(PC88MR-L18-400-A-Z0-A)
NEUTRAL
FORWARD and
REVERSE
NEUTRAL
FORWARD and
REVERSE
or both tracks)
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 }
0 MPa
{0 kg/cm 2 }
3.14 ± 0.5 MPa
{32 ± 5 kg/cm 2 }
40-497