35
11. If there is no fluid, add Mobil 1 15W-50 synthetic
motor oil or equivalent synthetic oil to approximately
1/4 in. (6 mm) below the top of reservoir baffle.
Important
Use oil specified or equivalent. Other fluids
could cause system damage.
12. Start engine and let run for about two minutes to purge
air from the system. Stop the engine and check for
leaks. If one or both wheels will not drive, refer
Bleeding Hydraulic System, page 35.
13. Recheck level and add fluid, if required. Do not
overfill.
Bleeding the Hydraulic System
The traction system is self bleeding, however, it may be
necessary to bleed the system if fluid is changed or after
work is performed on the system.
Air must be purged from the hydraulic system when any
hydraulic components, including oil filter, are removed or
any of the hydraulic lines are disconnected. The critical
area for purging air from the hydraulic system is between
the oil reservoir and each charge pump located on the top of
each variable displacement pump. Air in other parts of the
hydraulic system will be purged through normal operation
once the charge pump is ”primed”.
1. Disengage the PTO, turn the ignition key to off, and
remove the key. Wait for all moving parts to stop before
leaving the operating position.
2. Raise the rear of the machine up onto jack stands high
enough to raise the drive wheels off the ground.
3. Check Hydraulic fluid level.
4. Start engine and move throttle control to full throttle
position. Move the speed control lever to the middle
speed position and place the drive levers into the
”drive” position.
If either drive wheel does not rotate, it is possible to assist
the purging of the charge pump by carefully rotating the
tire in the forward direction.
Note: It is necessary to lightly touch the charge pump cap
(Fig. 46) with your hand to check the pump temperature. If
the cap is too hot to touch, turn off engine. The pumps may
be damaged if the pump becomes too hot. If either drive
wheel still does not rotate continue to next step.
1
m-5955
2
Figure 46
1.
Charge pump cap
2.
Socket head screw
5. Thoroughly clean the area around each of the charge
pump housings.
6. To ”prime” charge pump, loosen two hex socket head
capscrews (Fig. 46) 1–1/2 turns only. Make sure engine
is not running. Lift charge pump housing upward and
wait for a steady flow of oil to flow out from under
housing. Retighten capscrews. Do this for both pumps.
Note: Hydraulic reservoir can be pressurized to up to 5 psi
to speed this process.
7. If either drive wheel still does not rotate, stop and
repeat steps 4 and 5 on the respective pump. If wheels
rotate slowly, the system may prime after additional
running. Recheck hydraulic fluid level.
8. Allow unit to run several minutes after the charge
pumps are ”primed” with drive system in the full speed
position.
9. Check hydro control linkage adjustment. Refer to
Adjusting Hydro Control Linkages on page 38.
Checking the Hydraulic Lines
After every 100 operating hours, check hydraulic lines and
hoses for leaks, loose fittings, kinked lines, loose mounting
supports, wear, weather and chemical deterioration. Make
necessary repairs before operating.
Note: Keep areas around hydraulic system clean from grass
and debris build up.
