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f)
Raise the rear of the machine up onto jack stands high enough to raise the
drive wheels off of the ground. Run machine to allow any other air to be
purged from the hydraulic system and recheck the oil level.
g)
If either drive wheel does not rotate, one or both of the charge pumps
(located on the top of the main pump as shown in Figure 7) may have lost
their “prime”. Refer to Section 5.1.12.
h)
Do not
change hydraulic system oil
(except what can be drained when
changing filter)
unless it is felt that oil has been contaminated.
Changing oil unnecessarily could damage the hydraulic system by
introducing contaminates into the system.
5.1.12
Hydraulic system air purge procedure.
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. See Figure 7. Air in other parts of the hydraulic system will
be purged through normal operation once the charge pump is “primed”.
FIGURE 7
CHARGE PUMP LOCATION
a)
Stop engine and wait for all moving parts to stop. Raise the rear of the machine
up onto jack stands high enough to raise the drive wheels off the ground.
b)
Check oil level as stated in Section 5.1.10.
c)
Start engine and move throttle control ahead to full throttle position. Move
the speed control lever to the middle speed position and place the drive
levers in 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 position.
NOTE: It is necessary to lightly touch the charge pump cap 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 with step (d).
d)
Thoroughly clean the area around each of the charge pump housings.
e)
To “prime” charge pump, loosen two hex socket head capscrews (shown in
Figure 7)
1-1/2 turns only.
Make sure engine is not running.
Lift the
charge pump housing upward and wait for a steady flow of oil to flow out
from under the housing. Retighten the capscrews. Do this for both pumps.
Note: Hydraulic reservoir can be pressurized up to 5 psi to speed this process.
