541 Track Feller Buncher, 551 Track Feller Buncher and 552 Track Feller Buncher Machine Systems Caterpillar

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Sudden movement of the machine or release of oil under pressure can cause 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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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.

The line relief valves on the machine are unable to be adjusted. If the circuit operates at an incorrect system pressure, replace the line relief valve for that circuit.

Note: Put identification marks on all lines, on all hoses, on all wires, and on all tubes for installation purposes. Plug all lines, all hoses and all tubes. This helps to prevent fluid loss and this helps to keep contaminants from entering the system.

ReferenceFor the correct procedure in order to prepare the machine for this test, refer to Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.

ReferenceFor the correct procedure to relieve any hydraulic oil pressure that may be present in the hydraulic system, refer to testing and Adjusting, "System Pressure - Release" for the machine that is being serviced.

A temporary setting of the main relief valve on the implement control valve is required before you perform the test procedure.

Note: All indicated pressures will be checked at the pump outlet.

1. Place the machine on level ground.

2. Lower the work tool to the ground.

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Illustration 1	g01162081
The switch for the hood

3. Open the hood for the engine compartment.

4. Shut off the engine.

5. Release all hydraulic system pressure. See the reference at the start of this procedure for the correct method.

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Illustration 2	g01062785
Typical example (1) Pressure tap

1. Attach a 6V-3081 Hose As to pressure tap (1) that is located on the main hydraulic pump.

2. Attach the unconnected end of the hose assembly to a 198-4240 Digital Pressure Indicator .

3. Start the engine.

4. Warm the hydraulic oil to normal operating temperature. Normal operating temperature is 45° C (113° F) to 60° C (140° F).

5. Move the engine speed dial to high idle.

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Illustration 3	g01162712

6. Move the hydraulic lockout to the UNLOCKED position. When the hydraulic lockout is in the UNLOCKED position all the implements will function.

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NOTICE
Do not hold this function or any other function stalled for more than 10 seconds. Hydraulic oil is heated very rapidly when the oil is channeled through relief valves. Component damage could result.

7. Stall any of the following functions:
   • Boom up or boom down

   • Stick in or stick out

   Record the pressure while you are stalling the function.

   Note: The pressure will be identical for all the functions. It is not necessary to stall more than one function.

8. The implement pressure should be 35500 ± 300 kPa (5150 ± 50 psi). The travel pressure should be 35500 ± 300 kPa (5150 ± 50 psi).

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Illustration 4	g01750493

9. Loosen the locknut on main relief valve (1) .

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NOTICE
Use caution when adjusting the relief valve. A small turn can cause a large change in the relief pressure setting. Setting the relief pressure too high can cause significant component damage.

10. Turn the screw in order to adjust the pressure on the pressure gauge until the pressure gauge reads 40000 ± 700 kPa (5800 ± 101 psi). Turn the screw clockwise in order to increase the pressure. Turn the screw counterclockwise in order to decrease the pressure.

11. Tighten the locknut on main relief valve (1) .

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Illustration 5	g01753533
Felling head and intermittent saw (A) Line Relief Setting (A) (B) Line Relief Setting (B) (C) Signal Limiter Valve (Wrist) (D) Signal Limiter Valve (Wrist) (E) Signal Limiter Valve (Swing) (F) Signal Limiter Valve (Swing) (G) Signal Limiter Valve (Grab Arm) (H) Signal Limiter Valve (Grab Arm) (J) Signal Limiter Valve (Accumulator Arm) (K) Signal Limiter Valve (Accumulator Arm)

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Illustration 6	g01908513
Processing head (A) Line Relief Setting (A) (B) Line Relief Setting (B) (C) Signal Limiter Valve (Wrist) (D) Signal Limiter Valve (Wrist) (E) Signal Limiter Valve (Swing) (F) Signal Limiter Valve (Swing) (G) Signal Limiter Valve (Grab Arm) (H) Signal Limiter Valve (High Flow) (J) Signal Limiter Valve (High Flow) (K) Signal Limiter Valve (Low Flow)

12. Adjust the signal limiter valves to the maximum value on the implement control valve only in order to test the line relief valves for the controls:
    • Wrist function

    • Grab Arm

    • Accumulator Arm

13. Adjust engine speed to 1400 rpm.

14. Move the boom to the top of travel until the boom stalls. Record the indicated pressure.

    Note: Refer to Table 2 for proper indicated pressures.

15. Move the boom to the bottom of travel until the boom stalls. Record the indicated pressure.

    Note: Refer to Table 2 for proper indicated pressures.

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    Table 2

    Main Control Valve (7 BANK) Felling Head, Intermittent Saw, and Harvester Head
    Section	2	3	4	5	6	7	8
    Function	Boom	Stick	Wrist function (1)	Swing	Grapple Arms or Low, High Flow  (2)	Tool (3)	Accumulator Arms or Low, High Flow  (4)
    Line Relief Setting (A)	37500 kPa (5440 psi)	37500 kPa (5440 psi)	37500 kPa (5440 psi)	37200 kPa (5400 psi) (5)	30500 kPa (4420 psi)	37500 kPa (5440 psi)	30500 kPa (4420 psi)
    Line Relief Setting (B)	37500 kPa (5440 psi)	37500 kPa (5440 psi)	37500 kPa (5440 psi)	37200 kPa (5400 psi)	30500 kPa (4420 psi)	37500 kPa (5440 psi)	30500 kPa (4420 psi)
    Signal Limiter Valve (E)	-	-	28900 kPa (4190 psi)	-	-	-	-
    Signal Limiter Valve (F)	-	-	28900 kPa (4190 psi)	-	-	-	-
    Signal Limiter Valve (G)	-	-	-	35500 kPa (5150 psi)	-	-	-
    Signal Limiter Valve (H)	-	-	-	35500 kPa (5150 psi)	-	-	-
    Signal Limiter Valve (J)	-	-	-	-	24900 kPa (3610 psi)	-	-
    Signal Limiter Valve (K)	-	-	-	-	24900 kPa (3610 psi)	-	-
    Signal Limiter Valve (L)	-	-	-	-	-		24900 kPa (3610 psi)
    Signal Limiter Valve (M)	-	-	-	-	-		- 24900 kPa (3610 psi)

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    ( 1 )	The function is "Wrist " on the Felling Head or the Intermittent Saw. The function is "Rotate" on the Harvester Head.
    ( 2 )	The function is "Grapple Arms" on the Felling Head or the Intermittent Saw. The function is "Low, High Flow" on the Harvester Head.
    ( 3 )	The function is "Head Tilt" on the Felling Head or the Intermittent Saw. The function is not used on the Harvester Head.
    ( 4 )	The function is "Accumulator Arms" on the Felling Head or the Intermittent Saw. The function is "Low, High Flow" on the Harvester Head.
    ( 5 )	The relief valves are located on the swing motor.

16. Repeat Steps 13 through Steps 15 for each individual function that will be tested.

17. Restore the main relief valve back to the original setting of 35500 ± 300 kPa (5150 ± 50 psi).

18. Restore signal limiter valves back to the original settings.

19. Adjust engine speed to a low idle.

20. Shut off the engine.

21. Remove all hydraulic test equipment.