TK741, TK751 and TK752 Track Feller Bunchers Machine Systems Caterpillar

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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.

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Personal injury can result from contact with hot hydraulic oil and from contact with hydraulic oil that is under high pressure. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. The hydraulic oil pressure must be released before any service on the hydraulic system is performed or serious personal injury could occur. Verify that all of the work tools have been completely lowered to the ground. Release the hydraulic oil pressure at the hydraulic tank through the breaker relief valve when the breaker relief valve is cool enough to touch with your bare hand. Verify that the hydraulic oil is cool before you begin to remove any hydraulic components or hydraulic lines.

Note: Use the information in the reference to prepare the machine for this test. Also, use the information in the reference to relieve any system pressure that may be present in the hydraulic system.

Reference: For the correct procedure to prepare the machine for this test, refer to Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.

1. Place the machine on level ground.

2. Start the engine.

3. Run the engine at high idle.

4. Warm the hydraulic oil to normal operating temperature. Normal operating temperature is 55 ± 5°C (130 ± 10°F).

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Illustration 1	g01072433
"UP/DN" button

5. Use the "UP/DN" button to scroll between the seven screens in the operation state on the main display module (IQAN-MDM).

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Illustration 2	g01058691

6. Scroll to the screen that displays the pressure from the left pump and the right pump.

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Illustration 3	g00827520
Older models The hydraulic lockout control in the UNLOCKED position

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Illustration 4	g01162712
Newer models

7. Move the hydraulic lockout control to the UNLOCKED position.

8. Operate each of the following functions in the table below. The functions are equipped with pressure reducing valves. Monitor the pressure from the cab.
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   Table 2

   Function	Pressure
   Tilt CW	276 ± 5 Bar 27600 ± 500 kPa (4000 ± 70 psi)
   Tilt CCW
   Swing CW	338 ± 5 Bar 33800 ± 500 kPa (4900 ± 70 psi)
   Swing CCW
   Grapple (Open)	233 ± 5 Bar 23300 ± 500 kPa (3380 ± 70 psi)
   Grapple (Close)
   Accumulator (Open)	233 ± 5 Bar 23300 ± 500 kPa (3380 ± 70 psi)
   Accumulator (Close)
   Left Level	223 ± 5 Bar 22300 ± 500 kPa (3235 ± 70 psi)
   Right Level
   Forward Level	223 ± 5 Bar 22300 ± 500 kPa (3235 ± 70 psi)
   Backward Level

9. Record the readings on the display. If the readings are correct proceed to Step 14. If a function needs to be adjusted proceed to Step 10.

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Illustration 5	g01052558
Older models The switch for the hood

Note: The switch for the hood is located underneath the right armrest.

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Illustration 6	g01162081
Newer models

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Illustration 7	g01069398

10. Open the hood for the engine compartment.

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Illustration 8	g01070907
(1) Pressure tap on the main pump.

11. Attach the 198-4240 Digital Pressure Indicator to pressure tap (1) with the hose assembly.

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Illustration 9	g01070911
Signal Limiter Valves on the Implement Control Valve (2) Tilt control valve (3) Swing control valve (4) Grapple control valve (5) Accumulator control valve (A) Signal limiter valve CLOCKWISE (B) Signal limiter valve COUNTERCLOCKWISE (C) Signal limiter valve CLOCKWISE (D) Signal limiter valve COUNTERCLOCKWISE (E) Signal limiter valve OPEN (F) Signal limiter valve CLOSE (G) Signal limiter valve OPEN (H) Signal limiter valve CLOSE

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Illustration 10	g01070915
Signal Limiter Valves on the Travel Control Valve (6) Side leveling control valve (7) Forward leveling control valve (I) Signal limiter valve Left tilt (J) Signal limiter valve Right tilt (K) Signal limiter valve Forward (L) Signal limiter valve Backward

12. Adjust the function to the pressure in Table 2.

13. Remove the test equipment.

14. Move the engine speed dial to low idle. Shut off the engine.