 |
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. |
 |
|
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 and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak. |
|
|
Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine. |
|
| NOTICE |
|---|
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
The 4C-4890 Fittings, 8T-5320 Hydraulic Test Group, or 1U-5481 Pressure Gauges can be used to test the hydraulic system pressure. Before any tests are performed, visually inspect the entire hydraulic system for oil leaks and for damaged parts. For some of the tests, a magnet and a measuring rule (millimeters or inches) are usable tools.
When any test is performed on the hydraulic system or the steering system, the hydraulic oil must be at the normal operating temperature. To increase the oil temperature, start the engine and turn the machine in both directions. Also, raise the decking blade and lower the decking blade. Actuate the grapple through the full range of the grapple's operation. The oil is at normal operating temperature when the hydraulic oil temperature indicator is between the first mark and the second mark.
When you diagnose a problem in the hydraulic system or the steering system, a visual inspection of the affected system is the first step. Stop the engine and lower the decking blade to the ground. Also, lower the grapple to the ground. Perform the following inspections:
- Check the oil level in the sight gauge.
 | |
| Illustration 1 | g00713390 |
- Open the access door on the top of the engine enclosure. Carefully loosen filler cap (1) on the hydraulic tank in order to release the pressure in the tank. Remove filler cap (1) on the hydraulic tank.
 | |
| Illustration 2 | g00713391 |
- Look for air in the hydraulic tank oil immediately after the engine is stopped. Use a clear container to obtain a sample of the oil. Look for air bubbles in the oil in the container.
Reference: Refer to Operation and Maintenance Manual, SEBU7480, "525B Wheel Skidder and 535B Wheel Skidder", "Sampling Interval and Location of Sampling Valve" for information about obtaining a sample of the hydraulic system oil. Additional information can be obtained from Special Publication, PEHP6001, "How To Take A Good Oil Sample".
- Remove filter elements (2) and look for particles in filter elements (2). A magnet will separate ferrous particles such as iron and steel from the nonferrous particles such as aluminum and rubber. Install filter elements (2) and filler cap (1) on the hydraulic tank.
- Check for flow restrictions in all oil lines. Flow restrictions include acute bends in the oil lines, clamps that are not installed correctly, and physical damage to hoses and to lines. Check all oil lines and all connections for damage and for leaks.
- Inspect all of the control linkages for damage. Check the tightening torques of all bolts.