Daewoo Solar 420LC-V, Manual

Page: 15 / 151

Page 14
Hydraulic System Troubleshooting, Testing and
Adjustment
Return to Master Table of Contents
BOOM/FRONT PRIORITY VALVE
CONTROL VALVE PRESSURE AND CURRENT ADJUSTMENTS
The front priority control valves are located inside the compartment behind the cabin.
The same jumper harness used for testing the power mode (EPOS) control valve is used to test these two
valves. Turn off the engine, disconnect either of the electrical leads and connect the test equipment to that
side of the valve. An in-line "t-style" gauge adapter can be used to connect a 60 bar/870 psi (1,000 psi) test
gauge to the outlet (pressure) side of the valve. Set the engine control speed dial to maximum and warm
up the engine to at least 45°C (113°F) before making any tests.
NOTE:
Vent air from the hydraulic system before installing test equipment. Use the lever on the
reservoir, while the engine is running. Pour clean replacement fluid back into the system if
excessive fluid was lost.
Operate the swing and boom simultaneously. Measure signal current and hydraulic pressure through the
valve and record the highest and lowest values. Reset the work mode control to "digging" mode, and then
to "trenching" mode and repeat the same tests.
NOTE: If recorded values do not conform to the specified current or pressure in the table, readjust
as required.
WARNING!
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.
VALVE FUNCTION
DIGGING MODE TRENCHING MODE
VOLTAGE PRESSURE VOLTAGE PRESSURE
Front Priority
0 V
40 bar
(580 psi)
20 - 30 V
0 bar
(0 psi)
HAOB730L
HAOB740L