H-16 Time Lag Of Work Equipment Is Large - Komatsu PC88MR-10 Shop Manual

H-16 Time lag of work equipment is large

Time lag of work equipment is large.
Failure
Perform all troubleshooting with working mode set in power (P) mode.
Related
Pump pressure can be checked with monitoring function. (monitoring code: 01100)
information
No. Cause
Malfunction of boom
control valve
1
(regeneration valve)
Malfunction of arm
control valve
2
(regeneration valve)
Malfunction of boom
control valve (suction-
3
safety valve)
Malfunction of arm
control valve (suction-
4
safety valve)
Malfunction of bucket
control valve (suction-
5
safety valve)
Malfunction of boom
control valve (pressure
6
compensation valve)
(boom RAISE side)
Malfunction of boom
control valve (pressure
7
compensation valve)
(boom LOWER side)
Malfunction of arm
control valve (pressure
8
compensation valve)
(arm IN side)
PC88MR-10
Troubleshooting of hydraulic and mechanical system (H-
Procedure, measuring location, criteria, and remarks
a Release remaining pressure from hydraulic tank and piping, and then
perform troubleshooting with engine stopped.
Check for stuck or seized boom regeneration valve in control valve body.
(Spool must move smoothly and must not be caught.)
Check that regeneration valve (check valve ) is seated on control valve in
position (it is not stuck halfway), and then remove it from control valve
body and check it for defects and dirt.
Check spring of check valve for fatigue and deformation.
a Release remaining pressure from hydraulic tank and piping, and then
perform troubleshooting with engine stopped.
Check for stuck or seized arm regeneration valve in control valve body.
(Spool must move smoothly and must not be caught.)
Check that regeneration valve (check valve ) is seated on control valve in
position (it is not stuck halfway), and then remove it from control valve
body and check it for defects and dirt.
Check spring of check valve for fatigue and deformation.
a Check relief pressure of each work equipment. If relief pressure only of
boom cylinder head end is unusual, suction-safety valve of boom control
valve may malfunction.
a You can replace suction-safety valve with other one and check whether
failure symptom changes for judgment.
a Check relief pressure of each work equipment. If relief pressure only of
arm cylinder bottom end is unusual, suction-safety valve of arm control
valve may malfunction.
a You can replace suction-safety valve with other one and check whether
failure symptom changes for judgment.
a Check relief pressure of each work equipment. If relief pressure only of
bucket cylinder bottom end is unusual, suction-safety valve of bucket
control valve may malfunction.
a You can replace suction-safety valve with other one and check whether
failure symptom changes for judgment.
a Check whether boom cylinder moves slowly to RAISE side when
performing hydraulic relief of other work equipment. (If boom cylinder
moves, it is abnormal.)
a If any failure is found in above check item, interchange pressure
compensation valves between both ports, and check whether failure
symptom changes.
(Each area ratio is different, so be sure to restore it after checking the
symptom.)
a Check whether boom cylinder moves slowly to LOWER side when
performing hydraulic relief of other work equipment. (If boom cylinder
moves, it is abnormal.)
a Check whether arm cylinder moves slowly to arm IN side when performing
hydraulic relief of other work equipment. (If arm cylinder moves, it is
abnormal.)
40 Troubleshooting
(PC88MR-FTD-400-A-Z0-A)
mode)
40-487