H110ES, H115ES, H120ES, H130ES, H140ES, H160ES and H180ES Hydraulic Hammers Caterpillar

Testing the Hydraulic Accumulator

If the nitrogen charge in the hydraulic accumulator has been lost, the following symptoms have occurred:

• The hoses for the hammer have extensive pressure pulsation.

• Loss of impact power with the hammer

If you think that the nitrogen charge has been lost, the operation of the hydraulic accumulator can be examined by performing the following tests. These tests can be performed without removing the hammer from the host machine.

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Illustration 1	g02455478

1. Remove plug (1) from the housing of the hammer.

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Illustration 2	g02455558

2. Use a hex driver in order to remove outer plug (2) from port (A) of the accumulator.

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Illustration 3	g02455596

3. Screw 229-3440 Charging Adapter Group (K) into port (A) of the accumulator. Turn the charging tool at point (C) in order to install the charging tool. Tighten the charging tool to 60 ± 10 N·m (44 ± 7 lb ft) in order to properly seat the charging tool.

   Note: The 229-3442 Pin of 229-3440 Charging Adapter Group (K) should be properly inserted into the hex of the plug that is located within port (A) .

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Illustration 4	g02455617

4. Connect 121-6583 Accumulator Charging Group (H) to 229-3440 Charging Adapter Group (K) .

5. Close purge valve (5) on 121-6583 Accumulator Charging Group (H) .

6. Connect one end of 9U-6739 Hose Assembly (L) to 121-6583 Accumulator Charging Group (H) .

7. Connect the other end of 9U-6739 Hose Assembly (L) to 175-5507 Nitrogen Charging Group (J) .

8. Before you open the valve on the nitrogen gas cylinder, ensure that the adjusting screw on the regulator for the 175-5507 Nitrogen Charging Group (J) is completely backed out.

9. Carefully open the valve on the nitrogen gas cylinder. Set the regulator of 175-5507 Nitrogen Charging Group (J) to the preliminary pressure of 4500 kPa (650 psi).

10. Close the valve on the nitrogen gas cylinder. 9U-6739 Hose Assembly (L) is now pressurized and nitrogen gas is acting on the back side of the 3J-7354 O-Ring Seal (X) . This will prevent the 3J-7354 O-Ring Seal (X) from being damaged when the gas charge is checked.

11. To unscrew the inner plug, turn the hex driver at point (B) until the gas pressure can be read on the gauge of the charging tool. Do not exceed three complete turns.

12. Check the pressure on the gauge of the charging tool.

13. Add the necessary amount of nitrogen to achieve the proper level of charge. Refer to "Charging the Hydraulic Accumulator".

Charging the Hydraulic Accumulator

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Dry nitrogen is the only gas approved for use in the accumulator. Charging the accumulator with oxygen gas will cause an explosion. This danger will not happen if nitrogen cylinders with standard CGA (Compressed Gas Association, Inc.) Number 580 connections are used. When you order nitrogen gas, be sure that the cylinders are equipped with CGA No. 580 Connections. Do not use color codes or other methods of identification to tell the difference between nitrogen and oxygen cylinders.

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Illustration 5	g02455478

1. Remove plug (1) from the housing of the hammer.

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Illustration 6	g02455558

2. Use a hex driver in order to remove outer plug (2) from port (A) of the accumulator.

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Illustration 7	g02455596

3. Screw 229-3440 Charging Adapter Group (K) into port (A) of the accumulator. Turn the charging tool at point (C) in order to install the charging tool. Tighten the charging tool to 60 ± 10 N·m (44 ± 7 lb ft) in order to properly seat the charging tool.

   Note: The 229-3442 Pin of 229-3440 Charging Adapter Group (K) should be properly inserted into the hex of the plug that is located within port (A) .

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Illustration 8	g02455617

4. Connect 121-6583 Accumulator Charging Group (H) to 229-3440 Charging Adapter Group (K) . The following components are included in the 121-6583 Accumulator Charging Group :
   • 7Q-8499 Pin

   • 7Q-8498 Adapter

   • 3K-0360 O-Ring Seal

   • 9U-6740 Accumulator Charging Group

   • 8T-0856 Pressure Gauge

5. Close purge valve (5) on 121-6583 Accumulator Charging Group (H) .

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Illustration 9	g02455776

6. Connect one end of 9U-6739 Hose Assembly (L) to 121-6583 Accumulator Charging Group (H) .

7. Connect the other end of 9U-6739 Hose Assembly (L) to 175-5507 Nitrogen Charging Group (J) .

8. Carefully open the valve on the nitrogen gas cylinder. Set the regulator of 175-5507 Nitrogen Charging Group (J) to the preliminary pressure of 4500 kPa (650 psi).

9. Close the valve on the nitrogen gas cylinder. 9U-6739 Hose Assembly (L) is now pressurized and nitrogen gas is acting on the back side of the 3J-7354 O-Ring Seal (X) . This will prevent the 3J-7354 O-Ring Seal (X) from being damaged when the accumulator is charged.

10. Carefully open the valve on the nitrogen gas cylinder. Set the regulator of 175-5507 Nitrogen Charging Group (J) to the preliminary pressure of 5500 kPa (800 psi).

11. Wait for 10 minutes in order to allow the nitrogen gas pressure to stabilize inside the accumulator.
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    Table 3

    Temperature of the Gas	Gas Pressure
    0 °C (32 °F)	4659 ± 210 kPa (676 ± 30 psi)
    20 °C (68 °F)	5000 ± 205 kPa (725 ± 30 psi)
    40 °C (104 °F)	5341 ± 185 kPa (775 ± 27 psi)
    60 °C (140 °F)	5682 ± 200 kPa (825 ± 29 psi)

12. Adjust the accumulator pressure on the pressure gauge to the final pressure. Refer to Table 3 for determining the correct gas pressure at the given temperature of the gas.

13. After the correct pressure for the accumulator has been achieved, use socket drive (B) on the charging tool in order to tighten the plug within port (A) to a torque of 16 + 1.5 N·m (12 + 1 lb ft or 142 + 13 in ft).

    Note: Do not overtighten the plug. Failure of the hex in the plug may result.

14. Shut off the flow of nitrogen by closing the valve on 175-5507 Nitrogen Charging Group (J) .

15. Open purge valve (5) on 121-6583 Accumulator Charging Group (H) in order to relieve 9U-6739 Hose Assembly (L) of nitrogen.

16. Disconnect 9U-6739 Hose Assembly (L) from 121-6583 Accumulator Charging Group (H) .

17. Remove 121-6583 Accumulator Charging Group (H) from 229-3440 Charging Adapter Group (K) .

18. Remove 229-3440 Charging Adapter Group (K) from the accumulator.

19. Make sure that the O-ring seal on plug (2) is in good condition. Install plug (2) . Tighten plug (2) to a torque of 70 + 7 N·m (52 + 5 lb ft).