Machine Preparation
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Sudden movement of the machine or release of oil under pressure can cause serious injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system. |
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- Move the machine to a smooth horizontal location. Move away from working machines and personnel. Lower implements and lower the three-point hitch to the ground.
- Permit only one operator on the machine. Keep other service personnel in the view of the operator or away from the machine.
- Engage the parking brake.
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With the engine running, this machine spot turns when the steering wheel is turned, even with the transmission in NEUTRAL and the parking brake engaged. To avoid personal injury due to unexpected machine movement, make sure the area is free of personnel before starting the engine. Be prepared to apply the service brakes to counteract any steering that might occur when the engine starts. |
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- Turn off the engine.
- Move the control levers to all positions in order to release the pressure in the implement hydraulic system.
- Carefully loosen the filler cap on the hydraulic oil tank in order to release the pressure in the tank.
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Personal injury or death can result without releasing all of the hydraulic pressure. Release all the pressure from the hydraulic system before any lines are disconnected. |
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Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin. |
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- Move the steering wheel to the right and move the steering wheel to the left in order to release the pressure in the steering hydraulic system.
- Make sure that all hydraulic pressure is released before any fittings, any hoses, or any components are loosened, tightened, removed, or adjusted.
- Depress the brake pedal several times in order to release the hydraulic pressure that is stored in the brake accumulator. Pressing the brakes twenty times is sufficient for releasing the pressure.
- Tighten the filler cap on the hydraulic oil tank.
- The pressure in the system has now been released. Lines and components can be removed.
Procedure
When you are defining a problem in the implement, steering and brake hydraulic systems, the following procedure should be followed.
Perform the visual checks in Testing and Adjusting, "Visual Inspection". If you complete the visual Inspection and the problem is not identified, perform the operation checks. If you complete the operation checks and the problem is not identified, perform the instrument tests.
This procedure can help identify problems in the implement, steering and brake hydraulic systems. When the problem is defined, refer to Testing and Adjusting, "Troubleshooting". The troubleshooting section lists the probable causes of a known problem. Since more than one cause may exist for a problem, the troubleshooting section may suggest specific inspections or instrument tests. These inspections and tests will help identify the most probable cause.
Note: During a diagnosis of the implement, steering and brake hydraulic systems, remember that correct oil flow and pressure are necessary for correct operation. Oil pressure is caused by resistance to the flow of oil. Oil temperature must be a minimum of 60 °C (140 °F).
Refer to the Testing and Adjusting, "Troubleshooting" for the location and for the correction of problems that are in the implement, steering and brake hydraulic systems.
Troubleshooting Procedure
There are six steps to troubleshooting:
- Know the machine.
- Understand the symptom.
- Verify the symptom.
- Determine the probable causes.
- Reduce the list of probable causes.
- Test the system.
Use these steps to troubleshoot this machine.
Know the Machine
Understand the operation of the machine. Know if the symptom is a characteristic of normal operation or if the symptom is a failure.
Read the systems operation information in order to understand the systems of the machine. You must understand the interaction of the machine systems.
Understand the Symptom
You need to speak with the operator about the symptom.
- Ask about the performance of the machine prior to the failure.
- Determine the time of the first occurrence of the symptom.
- Determine the operating conditions at the time of the failure.
- Ask the operator about the sequence of events prior to the failure. Determine the order of the occurrences.
- Ask the operator about the steps that have been taken to troubleshoot the machine.
- Check the history of repairs of the machine.
- Ask about the preventive maintenance of the machine. Many failures are due to poor maintenance.
- Inspect the machine. Look for problems. Notice any unusual odors in the air. Listen for unusual noises.
Verify the Symptom
Operate the machine. When possible, repeat the conditions which caused the failure. Check the gauges inside the cab. Notice any unusual odors in the air. Listen for unusual noises.
Determine the Probable Causes
Use the information from the first three steps to create a list of probable causes. Determine the subsystem that is the cause of the symptom. Use the list of probable causes in the troubleshooting section as a guide.
Reduce the List of Probable Causes
List the probable causes in order of probability. Identify the probable causes that are easy to verify. When possible, eliminate probable causes that are easy to check.
Test the System
Use operational tests to verify the cause of the symptom. Once the cause has been identified, repair the failure. Then, test the system again.