| Tools Needed | ||
| Qty | Part Number | Description |
| 1 | 7S-5437 | Nitrogen Charging Group |
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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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Personal injury can result from the sudden release of high pressure oil. Be sure the engine has been shut off for a minimum of five minutes to be sure that the accumulator pressure is zero. The accumulator is filled with dry nitrogen. Do not loosen or remove the valve or cap from the top of the accumulator. A bleed screw at the bottom of the accumulator can be used to release the pressure that is left in the system. |
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When you are connecting the nitrogen charging equipment, never use an adapter that can be used on oxygen or other gas cylinders. MAKE SURE THAT YOU ARE USING DRY NITROGEN.
The hydraulic oil pressure in the all wheel drive accumulator must be removed. This must be completed before the all wheel drive accumulator can be tested. Remove the hydraulic tank cap in order to release any pressure that is remaining in the all wheel drive system.
Gas pressure is variable with temperature. The all wheel drive accumulator must be at the same temperature as the ambient air. This must be completed before the all wheel drive accumulator can be tested. Use Table 2 to determine the correct nitrogen charge for the ambient air temperature.
| Ambient Temperature | Pressure (1) | ||
| °C | °F | kPa | psi |
| -7 | 20 | 80.6 | 11.7 |
| 7 | 45 | 90.3 | 13.1 |
| 21 | 70 | 100 | 14.5 |
| 35 | 95 | 109.6 | 15.9 |
| 49 | 120 | 119.2 | 17.3 |
| ( 1 ) | The allowable tolerance on the nominal pressure is 6.9 kPa (1 psi) . |
- Remove valve guard (2) from all wheel drive accumulator (1) .
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| Illustration 1 | g00504000 |
This is a view from the front of the machine. (1) All wheel drive accumulator | |
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| Illustration 2 | g00503998 |
(1) All wheel drive accumulator (2) Valve guard | |
- Use the 345 kPa (50 psi) pressure gauge (9) in order to check the nitrogen charge in all wheel drive accumulator (1) .
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| Illustration 3 | g00503999 |
(3) Hose assembly (4) Valve (5) Pressure gauge (6) Nipple assembly (7) Chuck (8) Valve (9) Pressure gauge (10) Pressure regulating screw (11) Regulator assembly | |
- Disconnect valve (4) from hose assembly (3) . Make sure that valve (4) and valve (8) are closed.
- Install chuck (7) to the valve assembly on the all wheel drive accumulator.
- Slowly open valve (8) on chuck (7) . Check the temperature of the air around the all wheel drive accumulator. The pressure reading on pressure gauge (9) must be within the tolerances that are shown in Table 2 .
- If the pressure in the all wheel drive accumulator is too high, lower the pressure by slowly opening valve (4) .
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When the valve is opened with pressure in the cylinder, direct the flow of nitrogen away from all personnel. Pressurized nitrogen can cause serious injury. This procedure should be performed in an area that is well ventilated. High pressure gas can cause suffocation due to oxygen deficiency. |
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- If the pressure in the all wheel drive accumulator is too low, nitrogen must be added. Refer to Testing and Adjusting, "Accumulator (All Wheel Drive) - Charge" for information on charging the all wheel drive accumulator.
- Close valve (8) on chuck (7) . Slowly open valve (4) in order to release the pressure in the test line. When the pressure has been removed, disconnect chuck (7) from the valve assembly on the all wheel drive accumulator.
- Install valve guard (2) to all wheel drive accumulator (1) .
- Repeat this procedure for the other all wheel drive accumulator.