LUBRICATION
Transmission Purging Procedures
Due to the effects air has on efficiency in hydrostatic drive applications, it is critical to purge the system.
These purge procedures should be implemented any time a hydrostatic system has been opened to facilitate maintenance or any additional oil has been added to the system.
Resulting symptoms in hydrostatic systems may be:
•Noisy operation.
•Lack of power or drive after short term operation.
•High operation temperature and excessive expansion of oil.
Before starting, make sure the oil tank is at the proper oil level. If not, fill to the specifications outlined in this section.
The following procedures are best performed with the vehicle drive wheels off the ground, then repeated under normal operating conditions.
1.Disengage the brake if activated.
2.With the bypass valve open and the engine running at fast idle, slowly move the directional control in both forward and reverse directions (5 or 6 times). As air is purged from the unit, the oil level will drop.
3.With the bypass valve closed and the engine running, slowly move the directional control in both forward and reverse directions (5 to 6 times). Check the oil level and add oil as required after stopping the engine.
4.It may be necessary to repeat Steps 2 and 3 until all the air is completely purged from the system. When the hydraulic drive operates at normal noise levels and moves smoothly forward and reverse at normal speeds, the hydraulic drive is considered purged.
5.After the vehicle has been used two times, the oil level should be checked while the oil is cold and adjusted accordingly.
53