NOTE: The steering system and the hydrostatic
transmission system share a common
reservoir (located under the right hand
4-64. FILLING THE TANK.
4-65. Check the oil level when the hydraulic system is
cold and with the steering cylinder fully extended. The
oil in the hydraulic tank should be visible through the
sight gauge or slightly above gauge level when the oil is
cold. Add oil when no longer visible in the sight gauge
until oil fills the sight gauge window.
CAUTION: Do not completely fill the tank with oil. Air
space is designed into the tank for
operating temperature. No attempt should
be made to vent the hydraulic system.
4-66. CHANGING THE HYDRAULIC OIL.
4-67. After each 1,000 hours of operation or yearly
(whichever occurs first), the hydraulic oil should be
drained from the tank and replaced with new oil. This
removes dirt, water and mechanical wear particles that
have accumulated in the tank. Also, the chemical
structure of the oil deteriorates after prolonged use.
4-68. Drain the oil by removing the drain plug at the
bottom of the tank. Fill the tank through the filler neck
shown in figure 4-22.
CAUTION: Make absolutely sure that the oil level can
be seen in the sight guage before starting
the engine and operating the steering or
hydrostatic transmission systems.
4-69. TRANSMISSION HYDRAULIC FILTERS.
FIGURE 4-22. SERVICING THE HYDRAULIC
4-70. The suction filter should be checked every 100
hours of operation or at two week intervals by noting the
reading on the vacuum gauge. Change the filter element
if the reading exceeds 9 inches of mercury with oil
LUBRICATION THROTTLE AND
temperature at 100°F and engine at high idle. Always
TRANSMISSION LINKAGE (see
replace the suction filter element at least once a year or
1,000 hours, whichever occurs first.
4-62. Place a few drops of engine oil on the detent plate
NOTE: Removal of hydraulic lines or hoses is not
and crank arm connections every 100 hours of operation
required for replacement of the element in the
or at two week intervals.
suction filter assembly.