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Sudden movement of the tilt cylinders and/or rotator is possible if the tilt and rotate functions are not disconnected. Sudden movement of the tilt cylinders and/or rotator could result in serious injury or death. When checking and/or adjusting any of the harvester head pressures, the tilt circuit solenoids must be disconnected. If equipped, the rotate circuit solenoids must also be disconnected. |
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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system. |
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Personal injury or death can result from escaping fluid under pressure. Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak. |
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| NOTICE |
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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 product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products. Dispose of all fluids according to local regulations and mandates. |
Introduction
The following procedure is used to adjust the maximum pressure of the high pressure reducing (HPR) valve on the main control. The high pressure reducing valve controls the maximum pressure for all the head functions except the saw system. Excessive pressure could cause excessive wear/failure of the cylinders.
The following procedure is used to set the high pressure reducing valve on the main control valve.
Required Tools
| Required Tools | ||
| Part | Description | Quantity |
| 8T-5320 | Hydraulic Test Group | 1 |
| 198-4240 | Digital Pressure Indicator Gp | 1 |
| 177-7861 | Hose As | 1 |
Test Procedure
- Prepare the machine for test and adjust procedures. Refer to Testing and Adjusting, "Preparation for Troubleshooting".
- Harvester head in the HORIZONTAL position.
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| Illustration 1 | g02549477 |
The harvester head in the HORIZONTAL position. | |
- Open the valve cover on the harvester head. Disconnect the wire connectors from the tilt valve and the rotator valve if equipped.
- Attach a 0 to 25000 kPa (0 to 3625 psi) pressure gauge to pressure tap (1) (M4).
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| Illustration 2 | g02405697 |
Main Control Valve | |
- Disconnect the feed forward circuit by unplugging the wire connector from the solenoid.
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| Illustration 3 | g02405756 |
- Start the engine. Lower the hydraulic activation control lever. Raise the harvester head approximately 0.3 m (1 ft) above the ground.
- Set the engine speed to high idle. Activate the forward feed function. Pressure gauge should read 13500 kPa (1960 psi). If pressure is correct go to Step 9. If the pressure needs to be adjusted go to Step 8
- Unlock the set screw on pressure reducing valve (2) (HPR). Turn in to increase pressure, turn out to decrease pressure. Set the pressure to 13500 kPa (1960 psi). Tighten the locknut on pressure reducing valve (2) .
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| Illustration 4 | g02405696 |
Main Control Valve | |
- Deactivate the forward feed function. Reconnect the wire connector to the solenoid.
- Lower the harvester head to the ground.
- Shut off the engine. Remove the pressure gauge. Reconnect the wire connectors to the tilt valve and the rotate valve. Close the cover.
Worksheet
| HH44DE High Pressure Relief Valve Test and Adjust | ||
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| Item | Specification | Actual |
| Engine speed | High Idle | |
| High Pressure Relief Valve (HPR) | 13500 kPa (1960 psi) |
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