Charge Pump Location

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.

5.1.12Hydraulic 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

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.

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