IT38F Integrated Toolcarrier and 938F Wheel-Type Loader Secondary Steering System Caterpillar

Testing and Adjusting

Usage:

938F 2RM

Secondary Steering System

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Personal injury or death can result from escaping fluid under pressure.
Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue, causing serious injury, and possible death.
Always use a board or cardboard when checking for a leak.
Do not check for pin hole leaks in pump or motor hoses during a steer stall condition.

If fluid is injected into your skin, it must be treated by a doctor familiar with this type of injury immediately.

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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 steering hydraulic system:

Position the machine and the bucket on a level surface. Lower attachments to the ground. Stop the engine.

Permit only one operator on the machine. Personnel should be clear of the machine or personnel should be visible to the operator.

Engage the parking brake. Place blocks in front of the wheels and behind the wheels.

Push on the brake pedal many times. Push on the brakes until brake oil pressure is gone.

All hydraulic pressure must be released before any hydraulic components are worked on.

When any test is made to the steering hydraulic system, the hydraulic oil must be at the normal temperature for operation. To increase the oil temperature, start the machine. Lift the bucket and turn the machine in both directions. The 4C-4890 Hydraulic Test Group, 6V-7940 Hydraulic Test Group, 8T-5320 Hydraulic Test Group or 1U-5481 Pressure Gauge Group are used to test the pressures of the steering system. Before any tests are made, visually inspect the complete steering system for leakage of oil and for parts that have damage. For some of the tests, a magnet and a measuring rule (either inch or millimeters) are usable tools.

Visual Checks

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Personal injury can result from hydraulic oil under pressure.
Hydraulic oil under pressure can cause injury to persons on or near the machine when the pressure is suddenly released.
At operating temperature, the hydraulic oil tank is hot and under pressure. Hot oil can cause burns.
Remove the fill plug only when the engine is stopped, and the fill plug is cool enough to touch with your bare hand.

Do not allow hot oil or components to contact skin.

During the troubleshooting process, visually inspect the steering system and visually inspect the components.

Loosen the hydraulic tank filler cap slowly. Allow the tank pressure to lower before the filler cap is completely removed. Visually inspect the steering system with the following instructions:

Measure the level of the oil in the hydraulic tank.

Look for air in the oil that is in the hydraulic tank. Look for air immediately after the machine is stopped and after the pressure is relieved. Use a clear container to obtain a sample of the hydraulic oil. Look for air bubbles in the contained oil.

Check all oil lines, hoses and connections for damage or leaks.

Check for restrictions of flow. Restrictions of flow include sharp bends, clamps that are not installed correctly and physical damage to hoses and lines.

Remove the filter elements. Look for particles on the filter element. A magnet will separate ferrous particles from nonferrous particles.

Secondary Steering System Check

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Illustration 1	g00104443
Right Side Of Cab (1) Momentary switch. (2) OFF position. (3) ON position. (4) START position. (5) Ignition switch.

When ignition switch (5) is turned to ON position (3) or START position (4), the secondary steering relay activates the motor for 3 seconds which causes indicator (7) to light. The machine can be steered for three seconds. The light verifies that the system is working.

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