2006/06/05 Caterpillar

Excavator:

324D (S/N: CJX1-UP)

324D L (S/N: LAB1-UP; T2D1-UP; JJG1-UP; SYM1-UP; DFP1-UP)

324D LN (S/N: EJC1-UP)

324D FM (S/N: JKR1-UP; JLS1-UP)

325D (S/N: KDG1-UP; DBH1-UP)

325D L (S/N: GPB1-UP; KBE1-UP; MCL1-UP; PAL1-UP; AZP1-UP; A3R1-UP; GBR1-UP; SCR1-UP; T2S1-UP; CYW1-UP)

325D LN (S/N: PKE1-UP)

325D MH (S/N: C4H1-UP; RJK1-UP; LWR1-UP)

M325D L MH (S/N: EDF1-UP; KGG1-UP; KAY1-UP)

328D LCR (S/N: GTN1-UP; MKR1-UP)

330D (S/N: EAH1-UP; MEY1-UP)

330D L (S/N: GBC1-UP; NBD1-UP; B6H1-UP; THJ1-UP; FFK1-UP; ERN1-UP; JLP1-UP; MWP1-UP; HAS1-UP; RAS1-UP; EDX1-UP; T2Y1-UP)

330D LN (S/N: GGE1-UP)

Testing and Adjusting, RENR9619, "Relief Valve (Main) - Test and Adjust (Heavy Lift)". This module is part of Service Manual, RENR7373.Testing and Adjusting, KENR5755, "Relief Valve (Main) - Test and Adjust (Heavy Lift)". This module is part of Service Manual, KENR5750.Testing and Adjusting, RENR9585, "Relief Valve (Main) - Test and Adjust (Heavy Lift)". This module is part of Service Manual, RENR7450.Testing and Adjusting, RENR9679, "Relief Valve (Main) - Test and Adjust (Heavy Lift)". This module is part of Service Manual, RENR9680.Testing and Adjusting, RENR7235, "Relief Valve (Main) - Test and Adjust (Heavy Lift)". This module is part of Service Manual, RENR7230.Testing and Adjusting, RENR9595, "Relief Valve (Main) - Test and Adjust". This module is part of Service Manual, RENR9590.Testing and Adjusting, RENR7255, "Relief Valve (Main) - Test and Adjust (Heavy Lift)". This module is part of Service Manual, RENR7250 and Service Manual, RENR9910.Testing and Adjusting, RENR7385, "Relief Valve (Main) - Test and Adjust (Heavy Lift)". This module is part of Service Manual, RENR7380.Testing and Adjusting, RENR9905, "Relief Valve (Main) - Test and Adjust (Heavy Lift)". This module is part of Service Manual, RENR9900.

The procedure to test the main relief valve on machines that are equipped with heavy lift has been corrected. Use the information that follows for the revision of your books. The correct information is also available on SIS.

Relief Valve (Main) - Test and Adjust (Heavy Lift)

1. Position the machine on level ground and stop the engine.

2. Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release".

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Illustration 1	g01266656
Pump compartment (typical example) (1) Pressure tap (pressure for drive pump) (2) Pressure tap (pressure for idler pump) (3) Pressure tap (power shift pressure)

3. Attach a 60000 kPa (8700 psi) pressure gauge to pressure tap (1) .

4. Start the engine.

5. Place the machine controls at the following settings: engine speed dial "10" and AEC switch OFF. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine rpm settings.

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Illustration 2	g01267081

6. Set heavy lift switch (A) to the ON setting. Make sure that the indicator light is on.

7. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

8. Raise the boom until the boom cylinder rods are at full extension.

9. Check the pressure setting of the heavy lift at pressure tap (1) .

10. Return the joystick for the boom to the NEUTRAL position.

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Illustration 3	g01241161
Typical example (4) Main relief valve (5) Locknut for the heavy lift (6) Adjustment screw for the heavy lift (7) Locknut for the main relief valve (8) Adjustment screw for the main relief valve

11. The heavy lift relief valve pressure setting should be 36000 ± 500 kPa (5220 ± 73 psi). If the heavy lift relief valve pressure setting is not within the specification, adjust the heavy lift relief valve pressure setting.

    1. Loosen locknut (5) in order to adjust the relief valve for the heavy lift. Adjust the pressure by turning adjustment screw for the heavy lift (6) until the pressure gauge reading at pressure tap (1) is 36000 ± 500 kPa (5220 ± 73 psi).

       Note: Turning adjustment screw (6) clockwise increases the pressure. Turning adjustment screw (6) counterclockwise decreases the pressure.

       Note: Always make final pressure adjustments on pressure rise.

    2. Tighten locknut (5) to a torque of 70 ± 10 N·m (50 ± 7 lb ft).

       Note: Confirm the heavy lift pressure by raising the boom until the boom cylinder rods are at full extension.

12. Set heavy lift switch (A) to the OFF setting. The indicator light should not be illuminated.

13. Open the bucket until the bucket cylinder rod is at full retraction.

14. Check the main relief valve pressure setting at pressure tap (1) .

15. Return the joystick for the bucket to the NEUTRAL position.

16. The main relief valve pressure setting should be 35000 ± 500 kPa (5075 ± 72 psi). If the main relief valve pressure setting is not within the specification, adjust the main relief valve pressure setting.

Note: During adjustment of screw (8), do not allow screw (6) to move.

17. In order to adjust the main relief valve, loosen locknut (7) and turn adjustment screw (8) until the pressure gauge reading at pressure tap (1) is 35000 ± 500 kPa (5075 ± 72 psi).

    Note: Turning adjustment screw (8) clockwise increases the pressure. Turning adjustment screw (8) counterclockwise decreases the pressure.

    Note: Always make final pressure adjustments on pressure rise.

18. Tighten locknut (7) to a torque of 50 ± 10 N·m (37 ± 7 lb ft).

Temporary Setting of the Main Relief Valve

Note: In order to adjust line relief valve pressure settings, the main relief valve must be temporarily adjusted to a higher setting since the line relief valve pressure settings are higher than the main relief valve pressure setting.

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Illustration 4	g01267081

1. Set the heavy lift switch (A) to the ON setting. Make sure that the indicator light is ON.

2. The main relief valve pressure setting should be 36000 ± 500 kPa (5220 ± 73 psi) when the heavy lift mode is on. If the main relief valve is not within the specification, adjust the main relief valve pressure setting to the correct pressure specification before performing Step 3. Refer to Testing and Adjusting, "Relief Valve (Main) - Test and Adjust".

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Illustration 5	g01200818
Typical example (4) Main relief valve (5) Locknut for the heavy lift (6) Adjustment screw for the heavy lift (7) Locknut for the main relief valve (8) Adjustment screw for the main relief valve

3. Loosen locknut (5) .

4. Turn screw (6) clockwise by a quarter turn. Tighten locknut (5) while screw (6) is secured.

5. Perform the desired steps for testing and adjusting the line relief valves.

6. Reset main relief valve pressure setting to the normal operating condition. Refer to Testing and Adjusting, "Relief Valve (Main) - Test and Adjust".