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Hydraulic oil pressure can remain in the hydraulic system on this machine after the engine and pump have been stopped. Serious injury can result if this pressure is not released before any service is done on the hydraulic systems. In order to prevent possible injury, release the hydraulic system pressure before working on any fitting, hose, or hydraulic component. Lower all attachments to the ground before service is started. If the hydraulic system must be serviced, tested, or adjusted with the attachment in the raised position, the attachments and lift cylinders must be supported properly. Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made. |
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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. Dispose of all fluids according to local regulations and mandates. |
The following procedure will determine if the charge pressure is set correctly for the steering charge and pilot pressure pump.
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| Illustration 1 | g01089423 |
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Tooling (A) | |
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| Illustration 2 | g01623868 |
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Tooling (B) | |
| Required Tools | ||||
|---|---|---|---|---|
| Tooling | Item | Part
Number |
Description | Qty |
| A | A1 | 8T-0860 | Pressure Gauge
|
1 |
| A2 | 6V-3989 | Fitting | 1 | |
| A3 | 6V-4143 | Coupler | 2 | |
| A4 | 177-7861 | Hose As
|
1 | |
| B | B1 | 198-4234 | Digital Pressure Indicator | 1 |
| B2 | 198-4239 | Pressure Sensor |
1 | |
| B3 | 198-4236 | Adapter Cable As | 1 | |
- 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.
- Turn the key to the ON position, but do not start the engine.
- Verify that the implement lockout switch is in the UNLOCKED position.
- Move the control levers through the full range of travel several times which should relieve any pressure that may be present in the implement hydraulic system.
- Make sure that the pressure in the entire hydraulic system has been released.
- Turn the key to 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.
- Locate the pressure test port on the accumulator manifold. The accumulator manifold is located on the front of the hydraulic tank on the left side of the tractor.
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Illustration 3 g01946780 - Open access doors (1) and (2).
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Illustration 4 g01946798 - Attach tooling (A) or (B) to pressure port (S) on the accumulator manifold.
Test Procedure (Charge Pressure)
- Start the engine. Warm the hydraulic oil to a temperature of
65° ± 3°C (150° ± 5°F) . - Operate the engine at HIGH IDLE.
- Exercise the implement hydraulics. The charge pump pressure at port (S) should be
3050 ± 100 kPa (440 ± 15 psi) . - If the pressure is within the specified limit, the test is complete. If the pressure is not within the specified limit, perform the adjustment procedure in "Adjustment Procedure (Charge Pressure)".
Adjustment Procedure (Charge Pressure)
- Perform the steps in the "Machine Preparation" and then continue to the following steps.
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Illustration 5 g02448696 Show/hide table
Illustration 6 g02448739 (3) Locknut for the charge pressure
(4) Adjuster for the charge pressure - Loosen locknut (3) while you hold adjustment screw (4) in place.
- Turn adjustment screw (4) clockwise in order to increase the cutoff pressure. Turn adjustment screw (4) counterclockwise in order to decrease the cutoff pressure.
- Repeat the steps in "Test Procedure (Charge Pressure)" in order to check the charge pressure.
- After the pressure is adjusted within the specified limit, tighten locknut (3). Make sure that you hold adjustment screw (4) in place.
- Check the pressure at port (S) again. When the pressure is at the specified limit, the adjustment procedure is complete.
| D7E Test for the Steering Charge and Pilot Pressure Pump | ||
|---|---|---|
| Date | Equipment ID Code | |
| Item | Specification | Actual |
| Engine speed | High Idle | |
| Charge pump discharge pressure. (S) | |
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