Power Mode Valve; Current Signal And Hydraulic Pressure Adjustments - Doosan DX140R Shop Manual

POWER MODE VALVE

Current Signal and Hydraulic Pressure
Adjustments
This procedure should be done with two people. To reduce
the chance of accident or unintended start-up, one person
should remain at the operator's control stand while checks
and adjustments are made.
The electromagnetic pressure proportioning control (EPPR)
"power mode" valve is on the underside of the inclined plate,
located main frame center, above center joint. To test and adjust
power shift current and pressure through the power mode valve
a multilead jumper harness is required. The jumper harness
(which is available through DOOSAN After Sales Service, or
could be spliced together from commonly available, purchased
parts) has extra leads so that a VOM meter can be connected to
the circuit.
To set up the testing equipment, shut down engine and
disconnect the single electrical lead from the power mode valve.
Attach the jumper harness to the terminal on the valve, connect
the test leads of the multimeter to the extra leads on the harness
and reconnect the valve electrical lead.
Vent the lever on top of the hydraulic tank to relieve pressure
and connect an in-line "T-style" adapter to the valve pressure
port. Install a 60 bar (1,000 psi) test gauge in the adapter.
Restart the engine and increase engine rpm by turning the
speed control to the maximum speed setting. Warm up the
engine and hydraulic system until hydraulic oil temperature is at
least 45°C (113°F). Select Power Mode on the Instrument
Panel. Check current readings (in milliamps) on the VOM meter
and hydraulic pressure gauge readings and make sure both
conform to the values in the table below.
If recorded values do not conform to the specified
NOTE:
current or pressure in the table, back off the lock nut
on the end of the valve, turn the adjusting screw 1/4
turn and recheck current and pressure. Repeat
adjustment
performance and retighten the valve lock nut.
Mode
Power Mode High Idle: 1,900 rpm
Standard Mode High Idle: 1,850 rpm
Hydraulic System Troubleshooting, Testing and Adjustment
WARNING
as required to obtain
Engine RPM
Mid-range value corresponding to engine rpm for
both current and hydraulic pressure readings.
specified
Current
150 ± 20 mA
250 mA
Pressure
0 bar
(0 psi)
9 bar
(130.5 psi)
SP001942
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