Caterpillar 426 - Yearly Maintenance

Engine Valve Lash - Check | Check the engine valve lash after every 1000 service hours or 6 months on machines that are equipped with the following engine arrangements:

• • 122-8803 Primary Engine Arrangement

• • 122-8804 Engine Arrangement

• • 122-8805 Engine Arrangement

• • 122-8806 Engine Arrangement

Hydraulic System Oil - Change

• Pull the hood release lever (1) in order to open the engine access door (2) on the top of the machine.

• Remove the hydraulic tank filler cap.

• Remove the drain plug on the flange that is located on the hydraulic pump. Allow the oil to drain into a suitable container.

• Clean the drain plug and replace the drain plug. Tighten the drain plug to a torque of 90 ± 10 N·m (66 ± 7 lb ft).

• Change the hydraulic system filter. Refer to Operation and Maintenance Manual, “Hydraulic System Oil Filter - Change”.

• Inspect the hydraulic tank breather that is located on a hose from the overflow container. Replace the breather, if necessary.

• Fill the hydraulic system oil tank. Refer to Operation and Maintenance Manual, “Lubricant Viscosities” and Operation and Maintenance Manual, “Refill Capacities”.

• Maintain the hydraulic oil level in the sight gauge between the “MIN” mark and the “MAX” mark.

• Check the hydraulic oil level with the loader on the ground and with the backhoe in the transport position.

• The oil must be free of bubbles. If bubbles are present in the oil, air is entering the hydraulic system. Inspect the suction hoses and hose clamps.

• Inspect the gasket on the hydraulic tank filler cap for damage. Replace the gasket, if necessary.

• Install the hydraulic tank filler cap.

• Close the access door.