Initial Startup Procedures; Troubleshooting - JLG 1850SJ Service And Maintenance Manual

SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS

Initial Startup Procedures

Follow this procedure when starting-up a new pump or when
restarting a pump that has been removed. Ensure the pump is
thoroughly tested on a test stand before installing.
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 free of
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 hydraulic fluid to the
upper case drain port. If the controls are installed on top,
open the construction plugs in the top of the controls 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.
Ensure construction plug is closed after filling is com-
plete.
6. Disconnect the pump from all control input signals.
AFTER START-UP THE FLUID LEVEL IN THE RESERVOIR MAY DROP DUE TO
SYSTEM 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 HYDRAU-
LIC COMPONENTS. CHECK CAREFULLY FOR INLET LINE LEAKS.
DO NOT RUN AT MAXIMUM PRESSURE UNTIL SYSTEM IS FREE OF AIR AND
FLUID HAS BEEN THOROUGHLY FILTERED.
7. 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.
8. 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-
5-132
tions and listen for cavitation. Check for proper fluid
level in reservoir.
9. 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.
10. Shut the off engine. Connect the pump control signal.
Start the engine, checking to be certain the pump
remains in neutral. Run the engine at normal operating
speed and carefully check for forward and reverse con-
trol operation.
11. Continue to cycle between forward and reverse for at
least five minutes to bleed all air and flush system con-
taminants out of the system loop.
NOTE: Normal charge pressure fluctuation may occur during for-
ward and reverse operation.
12. Check that the reservoir is full. Remove charge pressure
gauge and cap port. The pump is now ready for opera-
tion.

Troubleshooting

HIGH INLET VACUUM CAUSES CAVITATION WHICH CAN DAMAGE INTERNAL
PUMP COMPONENTS.
ESCAPING HYDRAULIC FLUID UNDER PRESSURE CAN HAVE
SUFFICIENT FORCE TO PENETRATE YOUR SKIN CAUSING
SERIOUS INJURY AND/OR INFECTION AND MAY BE HOT
ENOUGH TO CAUSE BURNS. RELIEVE PRESSURE IN THE
SYSTEM BEFORE REMOVING HOSES, FITTINGS, GAUGES,
OR COMPONENTS. SEEK IMMEDIATE MEDICAL ATTENTION
IF YOU ARE CUT OR BURNED BY HYDRAULIC FLUID.
CONTAMINATION CAN DAMAGE INTERNAL COMPONENTS. TAKE PRECAU-
TIONS TO ENSURE SYSTEM CLEANLINESS WHEN REMOVING AND REIN-
STALLING SYSTEM COMPONENTS AND LINES
3121619