JLG 534D-10 - Manual (Page 103)

6.5 534D-9, 534D-10 & 544D
Hydrostatic Drive Pump
6.6 HYDROSTATIC DRIVE
PERFORMANCE CHECKS
These tests ensure that the Hydrostatic Drive System
operates to the proper specifications. All tests should be
done in a safe, open area. Apply the park brake and leave
the shifter in neutral unless otherwise noted. The boom
and attachment should rest on the ground unless the
machine is being driven.
Color-coded plastic caps seal the adjustments on
components in the hydraulic system. If a JLG Distributor
makes an adjustment, the component should be sealed
with a blue cap.
The following tools are needed for proper adjustments:
1. Tachometer
2. JLG pressure testing kit (P/N 77134197)
3. Mechanic’s hand tools (Metric included)
4. Blue plastic caps: P/N 80934459 (small) and
P/N 80934460 (large)
Testing and Adjustment Precautions
1. Read and understand the Operating & Safety
Manual. Be sure you are familiar with the machine’s
response to controls.
2. Read and understand all material relating to area to
be checked, adjusted or repaired.
3. This section of the manual covers hydraulic testing
and adjustments. Read and understand material
related to hydraulics before proceeding with service
of any kind on the hydraulic system. When
performing maintenance, be sure there is no residual
or trapped hydraulic pressure.
4. If you are working with a helper, be sure he
understands the procedure. Be certain each of you
know what to expect from the other, and when to
expect it.
5. Always wear safety glasses, hard hat and any other
locally required safety related protective apparel
when performing testing and adjusting procedures.
6. Thoroughly clean all areas before working on them.
Slippery and contaminated surfaces can cause
serious accident or mechanical failure if not
removed.
7. Always secure machine components that could
suddenly start in motion and cause injury or
damage.
8. Remove the key from the ignition and place a sign in
the cab informing all who come in contact with the
machine.
9. Double check all bolt torques.
10. Check that all lubrication fluids are at the correct
level.
11. Remove any restraints before restarting and
operating the machine following repairs.
12. Clear all personnel from area adjacent to the
machine when first operating after a repair or
adjustment.
13. Clean machine and work area before returning to
service.
6.6.1 Hydraulic Oil Reservoir
Make sure that the machine is level before retracting all
cylinders. Proper level is to full mark +/- 1/4 inch in the
sight gauge located on the outside of the reservoir. The
reservoir capacity is 30 gallons. Refer to Section 2.4,
“Fluid and Lubricant Capacities,” for system capacities.
6.6.2 Hydraulic Filter Condition
Dirty suction filters can restrict oil flow to the charge
pump. This can lower the control pressure which can
affect the machines ability to move, especially when
ambient pressure is below 32° F (0° C).
To check the hydraulic filter condition, warm the hydraulic
system oil to operating temperature
(100° F - 38° C minimum). Check the filter restriction
indicator on the return filter. The indicator should not
show filter bypass with the engine running at full throttle
and the park brake engaged. If the indicator shows
bypass, replace the suction and return filters.
For proper maintenance schedule see Section 2.5,
“Service and Maintenance Schedules.”
6.6.3 Engine Speed
Low engine RPM can reduce control pressure. Control
pressure determines machine speed. This condition can
slow the machine at full RPM.
Check engine speed with an adequate tachometer. At
low idle the engine speed should be 800 rpm. At high idle
with no load, the engine speed should be 2400 rpm
(534D-9), 2500 rpm (534D-10), 2200 rpm (544D). If either
the low or high idle is not within specification, contact your
JLG Service Distributor.