Hydraulic System, Purging - Snapper NZM21521KWV Safety Instructions & Operator's Manual

Section 5 - ADJUSTMENTS & REPAIR

5.12 HYDRAULIC SYSTEM, PURGING

After replacing or repairing hydraulic system
components, one or both of the wheel drives may
not pull properly. This is likely to be caused by air
entrapped in the system. If you experience a
pulling issue after completing repairs, perform the
following procedure to purge the air from one or
both of the hydraulic drive systems.
IMPORTANT: WHEN REPLACING THE HYDRAULIC
FLUID FILTERS, PRE-FILL BOTH WITH OIL
(SAE 20W50 API SL) BEFORE INSTALLING.
PRE-FILLING THE FILTERS WITH OIL WILL
REDUCE OR POSSIBLY ELIMINATE THE NEED
TO PURGE THE SYSTEM OF ENTRAPPED AIR
1. Locate hydraulic reservoir underneath
operator's seat. After thoroughly cleaning the area
around the top of the reservoir, remove filler cap.
Bring fluid to proper level (1 ½" below the top of
the filler neck). With engine off, add SAE 20W50
automotive oil. See Figure 4.6.
2. Open pressure relief valve on hydraulic pump,
turning counter clockwise 2 full turns. See Figure
3.3.
3. Carefully raise the rear of the machine so the
wheels are off of the ground. Securely block the
machine to prevent it from falling.
4. While seated in the operator's position, start the
engine. Place engine speed control in FAST
position.
5. Release parking brake and move motion
control levers out of the neutral lock position.
6. Slowly move motion control levers to the full
forward and then to the full reward positions.
Repeat this process 6 times.
7. Stop engine and wait for all rotation to stop
before leaving the operator's position.
8. Close pressure relief valve on hydraulic pump,
turning clockwise. Tighten snuggly.
9. With pressure relief valve closed, repeat Steps
4 thru 7.
10. Remove blocks and lower rear of machine.
11. Check fluid level in reservoir. Add SAE 20W50
automotive oil as required to bring fluid level to 1
½" from top of filler neck. Do Not over fill.
12. Install and tighten filler cap.
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