JLG sky trak mmv Service Manual page 619

Examine the fluid in the hydraulic oil sight glass (15) to
check whether there is a sufficient amount of fluid in the
system (the oil level should be at the mid-point of the sight
glass with all hydraulic cylinders retracted) and whether
the fluid is contaminated. Replace the hydraulic oil filter
as required.
15
a. Hydraulic Oil Filter Pressure Switch Removal
1. Remove engine side battery box cover (4). Remove
wing nuts (5) and carriage bolts (6) and set cover
and mounting hardware aside for later re-assembly.
2. Disconnect the negative (-) battery cable (1) at the
battery negative (-) terminal on the battery in the
engine side battery box.
3. Disconnect the negative (-) cable (2) at the bottom of
the battery equalizer (3).
4. Label and disconnect the hydraulic oil filter pressure
switch lead (10) from the harness connector (11).
5. Label and disconnect the hydraulic oil temperature
switch lead (12) from the hydraulic oil filter pressure
switch connector (13).
6. Unthread the hydraulic oil filter pressure switch (7)
from the hydraulic reservoir (14).
Model MMV Rev. 12/04
b. Disassembly
DO NOT disassemble the hydraulic oil filter pressure
switch. Replace a defective or faulty switch with a new
one.
c. Cleaning and Drying
DO NOT submerge the hydraulic oil filter pressure switch.
Clean only with an approved solvent and dry with a clean,
lint-free cloth.
d. Inspection and Replacement
Inspect switch wiring for continuity and shorting. Replace
a defective or faulty switch with a new one.
e. Installation and Testing
1. Thread the hydraulic oil filter pressure switch (7) into
its welded fitting on the hydraulic reservoir (14).
Tighten securely.
2. Connect the hydraulic oil filter pressure switch
lead (10) to the harness connector (11). Connect the
hydraulic oil temperature switch lead (12) to the
hydraulic oil filter pressure switch connector (13).
OT0690
3. Connect the negative (-) battery cable (1) at the
battery negative (-) terminal on the battery in the
engine side battery box.
4. Connect the negative (-) battery equalizer cable (2)
at the bottom of the battery equalizer (3). Torque the
nut to a maximum of 100 lbs/in (11 Nm).
5. Replace engine side battery box cover (4). Use the
wing nuts (5) and carriage bolts (6) to secure the
cover in place.
6. Clear the area around the vehicle of personnel and
any obstructions to vehicle travel.
7. Start the engine, check for hydraulic fluid leaking at
the hydraulic oil filter pressure switch, and allow the
hydraulic fluid to reach operating temperature.
8. Cycle the boom several times and check whether the
hydraulic oil filter restriction indicator illuminates on
the operator's display panel.
Electrical System
10.139