143H and 163H Motor Graders All Wheel Drive Operational Checks Caterpillar

The operation checks can be used to find leakage in the all wheel drive system. Also, the operational checks can help diagnose poor performance.

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Illustration 1	g01371116
(1) All wheel drive control

1. Start the engine. Turn all wheel drive control (1) to the MANUAL position or the AUTOMATIC position.

2. Listen for noise from the all wheel drive piston pump.

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Illustration 2	g00781160
(2) Torque control lever

3. Put the transmission direction and speed control in a gear and operate the machine. Move torque control lever (2) several times from the MINIMUM position to the MAXIMUM position.

4. Stop the machine. Engage the parking brake.

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Do not check for leaks with your hands. Pin hole (very small) leaks can result in a high velocity oil stream that will be invisible close to the hose. This oil can penetrate the skin and cause personal injury. Use cardboard or paper to locate pin hole leaks.

5. At the following components, check the hoses, the lines, the connections and the components for leakage:
   • The hydraulic oil tank

   • The hydraulic oil cooler

   • The all wheel drive filter

   • The all wheel drive gear pump

   • The all wheel drive piston pump

   • The flushing and cooling control valve

   • The control valve for the all wheel drive system

   • The all wheel drive piston motors

   • The all wheel drive accumulators