Husqvarna Z454 Owner Manual - Page 30

L U B R I C AT I O N Oil and Filters Change The hydraulic oil and filters must be replaced every 250 to 750 hours or once per year, depending on the type of oil used. See Qualified Hydraulic Oils in the Lubrication section for a list of approved oils or refer to the transmission manufacturers service manual. Due to the risk of impurities entering the system, all transmission work should be performed by an authorized service workshop. The following procedure is performed with the transmissions installed in the mower and the mower on level ground. Apply the pump release valve for each transmission and set the park brake. 1. Thoroughly clean the unit free of grass and other debris. Clean any loose debris from around the perimeter of the filter. 2. Remove breather / dipstick. 3. Place an oil drain pan (12" or more diameter and 8 qt. capacity is optimal) beneath the oil filter. 4. Using a socket and ratchet, remove filter plug and O-ring assembly. 5. Using a strong magnet or pair of needle nose pliers, remove the oil filter. 6. Install the new filter. 7. Install filter plug and O-ring assembly. Torque filter plug to 115-135 in/lbs. 8. Repeat steps on the opposite side. 9. Drain old oil filters of all free flowing oil prior to disposal. Place used oil in appropriate containers and dispose of it in accordance with laws in your area. Transmission Purging Purge procedures must be implemented if the hydrostatic system has been opened for maintenance or when more oil has been added to the system. Due to the effects air has on efficiency in hydrostatic drive applications, it is critical to purge the system. Resulting symptoms of air in hydrostatic systems may be: • Noisy operation. • Lack of power or drive after short term operation. • High operation temperature and excessive expansion of oil. • Shortened component life. Before starting, make sure the oil tank is at the proper oil level. If not, fill to the specifications outlined above. Perform the procedure first with the vehicle drive wheels off the ground, then repeated under normal operating conditions. See Moving Machine By Hand in the Operation section for bypass linkage adjustments. 1. Disengage the brake if activated. 2. With the bypass linkage 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 linkage 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 must be checked while the oil is cold and adjusted accordingly. 10. Fill transmission with Paker HT-1000 transmission oil or other approved hydraulic fluid. 11. The cold fluid level should touch the bottom of the breather/dipstick. 12. Install breather / dipstick and torque to 18-30 in./lbs. 30