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Pressurized System! Hydraulic accumulators contain gas and oil under high pressure. DO NOT disconnect lines or disassemble any component of a pressurized accumulator. All gas pre-charge must be removed from the accumulator as instructed by the service manual before servicing or disposing of the accumulator or any accumulator component. Failure to follow the instructions and warnings could result in personal injury or death. Only use dry nitrogen gas to recharge accumulators. See your Cat dealer for special equipment and detailed information for accumulator service and charging. |
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The track tensioning mechanism contains a hydraulic accumulator which acts as a spring to maintain track tension. Check the accumulator pressure whenever the track is adjusted or repaired. |
| Charging Pressure for the Accumulator at Different Temperatures | |
| Temperature | Pressure |
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Nitrogen gas pressure varies with the temperature. To obtain the most accurate nitrogen charge, the temperature of the accumulator must be the same as the air temperature around the accumulator. Use the specifications table to determine the correct accumulator precharge pressure/temperature relationship. Use dry nitrogen.
The following procedure will determine if the accumulators for the track tension system are charged to the appropriate pressure.
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| Illustration 1 | g01963393 |
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| Illustration 2 | g02726225 |
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Tooling (D) | |
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| Illustration 3 | g01964413 |
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Infrared thermometer Tooling (F) | |
| Required Tools | ||||
| Tool | Item | Qty | Part Number | Description |
| D | D1 | 1 | 162-4147(1) | Hose As |
| D2 | 1 | 8T-0859(1) | Pressure Gauge ( |
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| D3 | 2 | 8S-1506(1) | Coupling As | |
| D4 | 1 | 1S-8937(1) | Needle Valve | |
| D5 | 2 | 2D-7325(1) | Pipe Tee | |
| D6 | 1 | 2S-5244(1) | Fitting | |
| D7 | 1 | 346-3622 | Valve - Relief (Pop-Off) | |
| D8 | 1 | 338-0500 | Regulator | |
| D9 | 1 | 7S-5106(1) | Chuck | |
| D10 | 1 | 1S-8941(1) | Hose As | |
| D11 | 1 | 3F-2779 | Pipe Coupling | |
| F | - | 1 | 164-3310 | Infrared Thermometer |
| (1) | Part included in the 175-5507 Nitrogen Charging Group |
- Move the machine to a smooth horizontal location.
- Place the steering control lever in the NEUTRAL position.
- Engage the parking brake.
- Lower the attachments to the ground.
- Stop the engine.
- Make sure that the key is in the OFF position.
- Observe the state of the amber hazardous voltage present lamp. If the lamp is illuminated, do not perform any type of service on the machine. Wait until the lamp is not illuminated. Then, perform the lamp test in the next step.
- While you observe the lamp, turn the disconnect switch to the OFF position. Then turn the disconnect switch to the ON position.
Note: When the disconnect switch is cycled, the amber hazardous voltage present lamp will illuminate briefly. Then, the lamp will turn off which indicates that the operation of the lamp is correct.
- If an error message for the lamp circuit is displayed, or if the operation of the hazardous voltage present lamp does not appear to be correct, refer to the Troubleshooting, "General Information" section of the manual for information on troubleshooting the lamp circuit.
- Once the hazardous voltage level has been verified to be below 50.0 VDC, the machine can be serviced. Proceed to the next step.
Show/hide table
Illustration 4 g03703165 (1) Track tension adjust (access cover)
(2) Recoil system nitrogen accumulator (access cover)Note: Loss of Nitrogen (N2) charge in the recoil system may cause additional loosening of the track. This pressure may be retained inside the track roller frame. Take caution when removing the track adjust cover.
- Remove access cover (2) from the track roller frame.
- Loosen bottom bolt (B). Remove top bolt (A) and rotate protector cover (C) out of the way.
- Assemble Tooling (D). Turn the valve on chuck (D9) outward in the counterclockwise direction.
- Attach Tooling (D) to nitrogen charging valve (4) on the accumulator.
Note: Do not attach the regulator to the high-pressure nitrogen bottle at this time.
- Close needle valve (D4) by turning the valve inward in the clockwise direction.
- Turn the valve on chuck (D9) inward in the clockwise direction in order to open nitrogen charging valve (4).
- Observe the pressure at tooling (D2). Use Tooling (F) in order to check the temperature of the accumulator. Refer to Table 1 for the correct charging pressure.
- If the reading on the pressure gauge is too high, slowly open valve (D4) in order to vent some of the pressure. Remove the test equipment.
- If the reading on the pressure gauge is too low, proceed to "Charging Procedure".
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| Illustration 5 | g03703298 |
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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. |
- Attach Tooling (D) to the high-pressure nitrogen bottle.
- Attach Tooling (D) to nitrogen charging valve (4) on the accumulator.
Note: Before tightening the chuck on the nitrogen charging valve, open the regulator in order to purge the air out of the line. After all air has been purged from Tooling (D), tighten the chuck onto the charging valve.
- Use Tooling (F) in order to check the temperature of the accumulator. Refer to Table 1 for the correct charging pressure.
- Add
690 kPa (100 psi) more than the amount listed in table 1. - Allow the accumulator to stand for 10 minutes in order to stabilize the temperature.
- Add nitrogen or remove nitrogen in order to provide the correct charge pressure for the accumulator.