JLG 340AJ Service Manual - Manual (Page 218)

SECTION 5 - HYDRAULICS
5-60 – JLG Lift – 3121259
Initial Startup Procedures
GENERAL
Follow this procedure when starting-up a new pump installa-
tion or when restarting an installation in which the pump has
been removed and re-installed on a machine. Ensure pump
has been thoroughly tested on a test stand before installing
on a machine.
UNINTENDED MOVEMENT OF THE MACHINE OR MECHANISM MAY CAUSE
INJURY TO THE TECHNICIAN OR BYSTANDERS. TO PROTECT AGAINST UNIN-
TENDED MOVEMENT, SECURE THE MACHINE OR DISABLE/ DISCONNECT THE
MECHANISM WHILE SERVICING.
PRE-FILL PROCEDURE
The case of the pump MUST be pre-filled before starting the
engine. Failure to do so can cause premature failure of the
pump.
1. Fill the hydraulic reservoir.
2. Locate the L2 case port on the pump. It is located on the
back side facing the turntable side plate. Using a 9/16"
allen wrench, remove the O-ring plug.
3. When hydraulic oil starts to flow out of this port for
approximately 30 to 40 seconds, install the O-ring plug.
START-UP PROCEDURE
Prior to installing the pump, inspect for damage that may have
occurred during shipping.
1. Ensure that the machine hydraulic oil and system com-
ponents (reservoir, hoses, valves, fittings, and heat
exchanger) are clean and free of any foreign material.
2. Install new system filter element(s) if necessary. Check
that inlet line fittings are properly tightened and there
are no air leaks.
3. Install the pump. Install a 50 bar [1000 psi] gauge in the
charge pressure gauge port M3.
4. Fill the housing by adding filtered oil in the upper case
drain port. If the control is installed on top, open the
construction plug in the top of the control to assist in air
bleed.
5. Fill the reservoir with hydraulic fluid of the recom-
mended type and viscosity. Use a 10-micron filler filter.
Fill inlet line from reservoir to pump. Ensure construc-
tion plug in control is closed after filling.
6. Disconnect the pump from all control input signals.
7. Close construction plug removed in step 4.
AFTER START-UP THE FLUID LEVEL IN THE RESERVOIR MAY DROP DUE TO SYS-
TEM COMPONENTS FILLING. DAMAGE TO HYDRAULIC COMPONENTS MAY
OCCUR IF THE FLUID SUPPLY RUNS OUT. ENSURE RESERVOIR REMAINS FULL
OF FLUID DURING START-UP.
AIR ENTRAPMENT IN OIL UNDER HIGH PRESSURE MAY DAMAGE HYDRAULIC
COMPONENTS. CHECK CAREFULLY FOR INLET LINE LEAKS.
DO NOT RUN AT MAXIMUM PRESSURE UNTIL SYSTEM IS FREE OF AIR AND
FLUID HAS BEEN THOROUGHLY
8. Use a common method to disable the engine to prevent
it from starting. Crank the starter for several seconds. Do
not to exceed the engine manufacturer's recommenda-
tion. Wait 30 seconds and then crank the engine a sec-
ond time as stated above. This operation helps remove
air from the system lines. Refill the reservoir to recom-
mended full oil level.
9. When the gauge begins to register charge pressure,
enable, and start engine. Let the engine run for a mini-
mum of 30 seconds at low idle to allow the air to work
itself out of the system. Check for leaks at all line connec-
tions and listen for cavitation. Check for proper fluid
level in reservoir.
10. When adequate charge pressure is established (as
shown in model code), increase engine speed to normal
operating rpm to further purge residual air from the sys-
tem.
11. Shut off engine. Connect pump control signal. Start
engine, checking to be certain pump remains in neutral.
Run engine at normal operating speed and carefully
check for forward and reverse control operation.
12. Continue to cycle between forward and reverse for at
least five minutes to bleed all air and flush system con-
taminants out of loop.
NOTE: Normal charge pressure fluctuation may occur during for-
ward and reverse operation.
13. Check that the reservoir is full. Remove charge pressure
gauge.The pump is now ready for operation.