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Diesel engine exhaust contains products of combustion which may cause personal injury. Always start and operate the engine in a well ventilated area, and, if in an enclosed area, vent the exhaust to the outside. |
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Personal injury can result from rotating and moving parts. Stay clear of all rotating and moving parts. Never attempt adjustments while the machine is moving or the engine is running unless otherwise specified. The machine must be parked on a level surface and the engine stopped. Attach a "Do Not Operate" or similar warning tag to the start switch and controls before servicing, repairing, or making adjustments to the machine. |
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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine. |
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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
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Dry nitrogen is the only gas approved for use in the accumulators. The charging of oxygen gas in an accumulator will cause an explosion. An explosion can be eliminated by using nitrogen gas cylinders with standard CGA (Compressed Gas Association, Inc.) No. 580 connectors. When nitrogen gas is ordered, make sure to order the cylinders with CGA No. 580 connectors. Do not rely on color codes or other methods of identification to tell the difference between nitrogen and oxygen cylinders. In any application, never use an adapter to connect your nitrogen charging group to a valve outlet used on both nitrogen, oxygen, or other gas cylinders. BE SURE YOU USE DRY NITROGEN (99.8% purity). |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose of all fluids according to local regulations and mandates. |
| Relationship of Accumulator Precharge Pressure Temperature for a Typical |
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Nitrogen gas pressure varies with the temperature. Table 1 illustrates the pressure temperature relationship. To obtain the most accurate nitrogen charge, the temperature of each accumulator must be identical to the air temperature around the accumulators.
If the temperature of the accumulators is greater than the air temperature around the accumulators when performing this procedure. The temperature of the accumulator should be used instead of the ambient air temperature.
This procedure provides a method to test and recharge the accumulator for the track tension system. Inadequate accumulator pressure may cause poor traction and premature track wear.
| Required Tools | ||||
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| Tool | Item | Qty | Part No | Description |
| A | 9U-6740 | Accumulator Charging Gp | ||
| A1 | 1 | - | Fitting | |
| A2 | 1 | - | Pressure Gauge | |
| A3 | 1 | - | Adapter Cable As | |
| A4 | 1 | - | Knob | |
| A5 | 1 | - | Purge Valve | |
| A6 | 1 | - | Charging Hose | |
| A7 | 1 | - | Adapter | |
- Drive the machine to a smooth, horizontal surface.
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Illustration 1 g06049382 - Move propel lever (4) to the NEUTRAL position.
- Press parking brake switch (3) to change the status of the parking brake to "engaged". When the parking brake status is "engaged", an LED next to the parking brake switch will be illuminated.
- Use travel mode switch (2) to select the PAVE mode. When the travel mode switch is set to PAVE mode, an LED next to pave symbol (1) will be illuminated.
Note: The machine must be in PAVE mode to operate the screed lift system, hopper system, apron system, and auger lift system.
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Illustration 2 g06050624 - Use screed float switch (6) to place the screed in the FLOAT position. When the screed is in the FLOAT position, an LED next to the screed float switch will illuminate. Lower the screed to the ground.
- Press rpm decrease switch (7) for the throttle control once to operate the engine in low idle.
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Illustration 3 g03863272 - Shut off the engine. Either place machine power switch (8) in the OFF position or press and hold push to start switch (5) for 3 seconds. An LED next to the push to start switch will flash when the engine is in shutdown mode.
- If the engine was shut down using the push to start switch (5), move the machine power switch (8) to the OFF position.
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Illustration 4 g06187158 - Unhook latch (9), open access panel (10) on the right side of the machine.
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Illustration 5 g06187166 - Connect coupling (11) to fitting (13). Open needle valve (12).
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Illustration 6 g06187171 - Retract belt tension cylinder (14).
- Close needle valve (12).
- Disconnect coupling (11) from fitting (13).
Accumulator Test and Charge Procedure
Note: The machine is equipped with one track tension accumulator for the left track and one track tension accumulator for the right track. The following procedure is performed on the right track. This procedure is identical for the left side of the machine.
- Release the hydraulic pressure. Refer to the "Test Preparation" section.
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Illustration 7 g06187175 - Remove cap (15) from charging valve (16) on accumulator (17).
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Illustration 8 g06187181 - Rotate plug (18) counterclockwise by 60 degrees.
Note: Do not loosen plug (18) more than 60 degrees. Nitrogen in accumulator (17) will escape if the plug is loosened more than 60 degrees.
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Illustration 9 g03662372 Tool (A). - Ensure that purge valve (A5) on Tool (A) is closed.
- Screw adapter (A7) onto the accumulator.
- Use knob (A4) to loosen plug (18) on valve body (A3). When needle of pressure gauge (A2) begins to move, turn the knob one complete turn. The gauge now registers the accumulator precharge pressure.
- Check the temperature of the air around the accumulator, and check the temperature of the accumulator. Reading on pressure gauge (A2) must be within the tolerances listed in Table 1.
- If reading on pressure gauge (A2) is too high, slowly open accumulator purge valve (A5) to lower the pressure. If the reading on the pressure gauge is too low, use the following procedure to charge the accumulator:
- Close accumulator purge valve (A5). Connect charging hose fitting (A1) and connect charging hose (A6) to the nitrogen cylinder.
- Open the valve on the nitrogen cylinder.
- Slowly open accumulator purge valve (A5), and charge the accumulator. Close the accumulator purge valve when pressure on gauge (A2) corresponds to the tolerance listed in Table 1.
- If pressure reading on gauge (A2) decreases, repeat Step 8.c.
- The accumulator is charged when reading on gauge (A2) does not change after accumulator purge valve (A5) is closed.
- Close the valve on the nitrogen cylinder.
- Use knob (A4) to close plug (18). Remove the test equipment.
- Tighten plug (18) to a torque of
25 ± 6 Nm (19 ± 4 lb ft) . - Spray soapy water onto accumulator charging valve (16) to check for leaks.
- If no leaks are present, install cap (15).
- Recharge the hydraulic side of the accumulator. Refer to the following section, "Accumulator Test and Charge Procedure".
Hydraulic Pressure Recharge Procedure
Note: The machine is equipped with one track tension accumulator for the left track and one track tension accumulator for the right track. The following procedure is performed on the right track. This procedure is identical for the left side of the machine.
- Connect purge hose to tap (19), which is on the belt tension cylinder. Place the open end of the purge hose into a container which is suitable for the collection of hydraulic oil.
Note: The purge hose is stored in the machine toolbox.
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Illustration 11 g03796400 - Connect coupling (11) to fitting (13). Open needle valve (12).
- Move machine power switch (8) to the ON position.
- Press push to start switch (5) for 2 seconds to start the engine. An LED next to the push to start switch will flash when the engine is in start mode. When the engine has started, the LED will remain illuminated.
Note: Only one attempt to start the engine is allowed per key cycle. A new key cycle is necessary to restart the process.
- To open the quick disconnect fitting on the purge hose, hold the fitting and turn the hose. Allow the oil to flow into the container. When only oil flows from the hose, close the quick disconnect fitting.
- Remove purge hose from tap (19). Return the purge hose to the machine toolbox.
- Close needle valve (12).
- Shut off the engine. Either place machine power switch (8) in the OFF position or press and hold push to start switch (5) for 3 seconds. An LED next to the push to start switch will flash when the engine is in shutdown mode.
- If the push to start switch (5) was used to shut off the engine, move machine power switch (8) to the OFF position.
- Remove coupling (11) from fitting (13).
Note: If necessary, wait for short period before coupling (11) is disconnected. The pressure in the line must decrease before the coupling can be disconnected.
- Close access panel (10) on the right side of the machine and secure latch (9).
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| Illustration 10 | g06187193 |
