Fiat Kobelco EX355 Tier2, Техническое руководство

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EX355 T5-4-11
TROUBLESHOOTING B
Bypass Shut-Off Valve
• When only the front attach-
ment function is operated,
pressure oil in the 4-spool
side control valve is routed
to front attachment spool so
that front attachment speed
is ensured.
• The same as described be-
low.
• If the spool is seized in the
fully opened position, front
attachment single operation
speed decreases.
• If check valve is seized in
the fully closed position,
when all control levers are in
neutral, the main relief valve
keeps relieving. At that time,
pump 1 control pressure in-
dicates maximum.
• Pressure difference will dif-
fer depending on the degree
of seizure, but when all con-
trol levers are in neutral,
pump 1 delivery pressure is
kept higher than pump 2
delivery pressure.
-
• Pump 1 control pressure.
Pump1 and 2 delivery pres-
sure.
-
-
-
T3-3
NOTE - The measurement of the control voltage of proportional solenoid valves SG,
SI, SD and SC, must be performed with test harness (75301514) meaning
that the main controller (MC) output must be connected to the load of the
solenoid valve. Under this test configuration, the normal control voltage
changes from 5 through 10 Volt.
On the other hand, when measuring the control voltage directly on the
connector disconnected from the solenoid valve (harness side) the voltage
measured is always 24 Volt and this is irrelevant in troubleshooting the
solenoid valve.