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 disassembling the hammer.
| Required Tools | ||
| Part Number | Part Description | Quantity |
| 8T-7910 | Adapter | 1 |
| 6V-0405 | Seal | 1 |
| 6V-3965 | Quick Disconnect Fitting | 1 |
| 4C-4892 | ORFS Fittings Group | 1 |
- Connect a pressure gauge that is dampened to the pressure measuring port (A) of the hammer. The pressure gauge should be rated at
25000 kPa (3600 psi) .Show/hide table
Illustration 2 g00986342 Needle Fluctuation of the Pressure Gauge
(B)1000 kPa (145 psi)
(G) Average Pressure - Operate the hammer. Inspect the needle movement of the pressure gauge. The normal needle fluctuation of the pressure gauge is approximately
1000 kPa (145 psi) to2000 kPa (290 psi) . If the pulsation is more than2000 kPa (290 psi) , then there could be failure in the hydraulic accumulator.
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| Illustration 1 | g00687969 |
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Needle Fluctuation of the Pressure Gauge (A) Pressure Measuring Port | |
When you stop operating the hammer, follow the needle movement of the pressure gauge.
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| Illustration 3 | g00690195 |
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(D) Slow drop
(E) Rapid drop (F) Accumulator Precharge Pressure (G) Operating Pressure of hammer | |
The needle on the pressure gauge will drop downward slowly. The drop in the pressure may take several minutes. The drop is difficult to determine. This slow drop (D) will continue until the needle gets near accumulator precharge pressure (F) of the hydraulic accumulator. Accumulator precharge pressure (F) is
Note: If the pressure drop can not be recognized in these two separate phases, the nitrogen pressure in the hydraulic accumulator has been lost.
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. |
| REQUIRED TOOLS | |||
|---|---|---|---|
| Tool | Part Number | Part Description | Quantity |
| H | 121-6583 | Accumulator Charging Group | 1 |
| J | 175-5507 | Nitrogen Charging Group | 1 |
| M | 7Q-8502 | Pin(1) | 1 |
| N | 7Q-8501 | Adapter(1) | 1 |
| U | 9U-6741 | Adapter(2) | 1 |
| V | 1P-7326 | Washer(2) | 1 |
| W | 8T-7860 | Connector(2) | 1 |
| X | 3J-7354 | O-Ring Seal (2) | 1 |
| Y | 5P-2937 | Adapter(2) | 1 |
| Z | 5P-8998 | Nipple(2) | 1 |
| AA | 8S-4599 | Quick Disconnect Fitting(2) | 1 |
| BB | 2S-5244 | Fitting(2) | 1 |
| (1) | Only for 140 and H140 |
| (2) | Only for connecting 9U-6740 Accumulator Charging Group to 175-5507 Nitrogen Charging Group |
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| Illustration 4 | g00634562 |
- Install a new 3Q-7749 Seal (T) before you charge the accumulator. The existing 3Q-7835 Purge Screw (S) can be used on the accumulator. If the 3Q-7835 Purge Screw (S) is damaged, replace the screw.
- Connect 121-6583 Accumulator Charging Group (H) to the hydraulic accumulator. The following components are included in the 121-6583 Accumulator Charging Group (H):
- 7Q-8499 Pin (M)
- 7Q-8498 Adapter (N)
- 3K-0360 O-Ring Seal (R)
- 9U-6740 Accumulator Charging Group (H)
- 8T-0856 Pressure Gauge (K)
Note: 7Q-8501 Adapter (N) and 7Q-8502 Pin (M) should be used in place of 7Q-8498 Adapter (N) and 7Q-8499 Pin (M), when you charge the 140 and H140 hydraulic hammer.
- Connect 175-5507 Nitrogen Charging Group (J) to the nitrogen gas cylinder.
Show/hide table
Illustration 5 g00691543 - Connect 9U-6740 Accumulator Charging Group to 175-5507 Nitrogen Charging Group (J). Refer to Table 2 and Illustration 5 for the required parts in order to connect the two groups together.
- When the two groups have been connected together, close the discharge valve (L) on the 9U-6740 Accumulator Charging Group.
- Open 3Q-7835 Purge Screw (S) through 9U-6740 Accumulator Charging Group with three turns.
Note: Before you open the valve on the nitrogen gas cylinder, you must ensure that the adjusting screw on the regulator for the 175-5507 Nitrogen Charging Group (J) is completely backed out.
- 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) . - Wait for ten minutes in order to allow the nitrogen gas pressure to stabilize inside the accumulator.
- Adjust the accumulator pressure on pressure gauge (K) to the final pressure of
4000 kPa (580 psi) . - Tighten 3Q-7835 Purge Screw (S) to a torque of
20 N·m (15 lb ft) . Do not overtighten the screw. - Release the pressure from the charging hose by opening discharge valve (L).
- Remove 121-6583 Accumulator Charging Group (H) from the accumulator.
- Check the accumulator for a nitrogen leak. The nitrogen leak can be detected in the area of the seal (T). Fill the area with oil in order to detect a nitrogen leak. A nitrogen leak will cause bubbles in the oil. When this occurs, the pressure in the accumulator should be released. The accumulator needs to be recharged. Refer to step 14. If the accumulator does not leak, go to step 15.
- Repeat steps 1 through 10.
- Install plug (P).
