906 and 908 Wheel Loaders Hydraulic and Steering System Caterpillar

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To help prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic and steering system:

When you are analyzing a hydraulic system or a steering system for poor performance, remember that correct oil flow and correct oil pressure are necessary for correct operation. Oil flow is a function of the pump output. The pump output is a function of engine speed. A restriction to the flow of oil causes oil pressure.

Before any tests are performed, visually inspect the complete hydraulic system for oil leaks and for damaged parts. Refer to Testing and Adjusting, "Visual Inspection" for further information on visual inspection.

When any test is made to the hydraulic system or a steering system, the hydraulic oil must be at normal temperature for operation. In order to increase the oil temperature, start the engine. Raise and lower the work tool. Articulate the machine in both directions.

Note: Permit only one operator on the machine. Keep other personnel away from the machine or in the operator's sight.

1. Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel.

2. Lower the work tool to the ground. Stop the engine.

3. Turn the steering wheel to the left and to the right in order to release the pressure in the steering system.

4. Engage the parking brake.

5. Place chocks in front of the wheels and behind the wheels.

6. Turn the engine start switch key to the ON position.

7. Move the work tool controls to all positions in order to release the pressure in the hydraulic system.

8. Turn the engine start switch key to the OFF position.