Service manual

REV C 4-6 115615
Hydraulic System
IMPORTANT: Never use hydraulic or automatic transmis-
sion fluid in this system; use only motor oil as specified.
Remember, dirt is the primary enemy of any hydraulic system.
Check oil level in hydraulic system after every 50 hours of
operation or weekly, whichever occurs first. Check more often if
system appears to be leaking or otherwise malfunctioning.
Fluid level should be 1” (2.54cm) from top of reservoir.
(Figure 4-15) Use only SAE 20W50 SL/SM service motor oil
for the BigDog
®
Mowers X Diablo.
Change hydraulic system filter element and oil after first 50
hours of mower operation, then replace filter and oil in reservoir
every 500 hours thereafter.
Use a 15/16” socket for the hydraulic system filter. The
threads are right hand. Figure 4-16
The hydraulic system filter is located inside the hydraulic res-
ervoir on the underneath side of the tank. Use a BigDog
®
Mow-
ers approved filter element only. Figure 4-16
Hydraulic oil heat exchanger
The BigDog
®
X Diablo mower is equipped with a hydraulic
oil heat exchanger. The heat exchanger coils must be kept clean
to insure that the hydraulic oil is operating within the correct
temperature range.
Check and clean the heat exchanger daily and more often in
dirty, dusty conditions. Figure 4-17
Hydraulic Pump Flow Test
The design purpose of the Bi-Directional Flow Test Kit is to
allow the customer to isolate the pump from the wheel motor
and determine if the pump is acceptable. The following informa-
tion can be used to install and test the pump by simulating a
WARNING
Hydraulic fluid escaping under pressure may have
sufficient force to penetrate skin and cause serious
injury. Foreign fluid injected into the skin must be
surgically removed within a few hours by a doctor,
familiar with this form of injury, or gangrene may
result.
Before applying pressure to hydraulic system, make
sure all connections are tight and all hoses and lines
are in good condition. To find a leak under pressure,
use a piece of cardboard or wood — never use your
hands. Relieve all pressure in the system before dis-
connecting or working on hydraulic lines. To relieve
pressure, lower all attachments and shut off engine.
Figure 4-16
Hydraulic filter
Hydraulic
reservoir
Figure 4-15
Figure 4-17
Hydraulic
reservoir
Heat exchanger