TM 5-3805-280-24-1
Diagnostic Information
Propel-Boom Down Selector
Arm Regenerative Valve
Propel Flow Control Valve
Valve
Operational Function
To route oil from rod end to head
To reduce shock load created by
To ensure boom down force
end of cylinder during arm in when
going from propel operation to
during combined operation of
shifted by arm regenerative solenoid
combined operation of propel and
propel and boom down.
valve.
dig by gradually restricting oil flow
from power passage.
Control Problems
No pressure signal from arm
Oil flow not restricted because spool
Boom II spool not shifted during
regenerative solenoid valve to shift
is stuck or no pressure signal to
combined operation of propel
arm regenerative valve spool. Valve
shift propel flow control valve spool.
and boom down. Boom II spool
spool is sticking or stuck.
is shifted during just boom down
operation.
Machine Symptoms
During arm in, there is arm cylinder
When stuck closed, shocks felt
When stuck closed: boom down
cavitation and controllability
when changing from propel to
speed is fast, swing speed slow
becomes less.
combined propel and dig operation.
at full stroke during combined
When stuck open, no boom up
swing and boom down operation.
when combined with propel down a
slope or with bucket loading.
Laptop Computer with
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Excavator Diagnostic
Software Self-Diagnostic
Functions
Laptop Computer with
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Excavator Diagnostic
Software Monitoring
Function
Harness Check
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Notes
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Description of Operation
See Arm Regenerative Valve
See Propel Flow Control Valve
See Propel-Boom Down Selector
9025
Operation in Group 9025-05.
Operation in Group 9025-05.
Valve Operation in Group
15
9025-05.
10
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TX,15,GG2238
1913AUG989/10
6-99
