Air Purging Procedure for Hydrostatic Transmissions

1. Check oil level.
2. Place vehicle's drive axle on jack stands with wheels off floor.
3. Start engine and operate at low idle speed.
4. Depress and hold the forward pedal and open and close the bypass (tow) valve a few times. Next do the same for reverse. This only takes a couple of seconds to do. Note the bypass is typically the rod that is located on the back of the tractor that you can pull out to free-wheel the unit. Also note that this may take a partner or some assistance.
5. Depress the forward and reverse pedal(s) in a back and forth type motion with the bypass valve in the run position.
6. Repeat steps 4 and 5 until the axles start to move. This should only take a couple of times.
7. When the axle starts to move, increase the engine speed.
8. Repeat depressing the forward and reverse pedal until transaxle gives full response.
9. Turn the engine off. Remove jack stands while placing vehicle's wheels on floor.
10. Recheck and top-off oil level.