Testing and Adjusting the Manual Displacement Control of the Propel Pumps
Introduction
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Sudden movement of the machine or release of oil under pressure can cause serious 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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| 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, "AVSpare Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on AVSpare products. Dispose of all fluids according to local regulations and mandates. |
This test is designed to determine if the manual displacement control for each propel pump is in the NEUTRAL position.
Required Tools
Hydraulic test procedures may be performed using either one of the following test equipment:
- Digital Pressure Indicator
- Standard tooling
Digital Pressure Indicator
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| Illustration 1 | g00931365 |
Table 1 provides a list of the required tools if the 198-4240 Digital Pressure Indicator is used to perform the following test procedure.
| Required Tools Digital Pressure Indicator |
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|---|---|---|---|---|
| Tool | Item | Part Number | Description | Qty |
| A | A1 | 198-4234 | Digital Pressure Indicator | 1 |
| A2 | 198-4238 (1) | Pressure Sensor 0 - 34500 kPa (0 - 5000 psi) |
2 | |
| ( 1 ) | This pressure sensor is an optional item. This sensor is not included in the 198-4240 Digital Pressure Indicator. The sensor must be ordered separately. |
Standard Tooling
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| Illustration 2 | g00931367 |
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| Illustration 3 | g00931368 |
Use the tools in Table 2 to complete the following test procedure.
| Required Tools (Standard Tooling) | ||||
|---|---|---|---|---|
| Tool | Item | Part Number | Description | Qty |
| B | B1 | 177-7860 | Hose As | 2 |
| 6V-4143 | Coupler | 4 | ||
| B2 | 8T-0855 | Pressure Gauge 0 - 4000 kPa (0 - 580 psi) |
2 | |
| 6V-3989 | Fitting | 2 | ||
| C | - | 4C-6500 | Digital Thermometer | 1 |
Use the following procedure before you perform the testing and adjusting:
- Apply the parking brake.
- Place the propel control lever in neutral.
Test Procedure
The 198-4240 Digital Pressure Indicator was used in the following test.
- Remove linkage (3) between the two manual displacement control levers. Install Tool (A2) on pressure taps (X1) and (X2) .
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| Illustration 4 | g00931473 |
- Start the machine and run the engine at high idle at 2310 ± 50 RPM. Check the hydraulic temperature with Tool (C) until the hydraulic oil temperature reaches 38°C (100°F).
- Record the pressures on the gauges. The pressure readings should be identical.
- If the pressure is correct, shut off the engine and remove the gauges.
Adjusting Procedure
- Shut off the engine.
- If the readings are not identical, loosen lock screw (1) for set screw (2).
Note: Adjustment screw (2) is an eccentric adjuster. One half of a revolution of the adjustment screw gives all the adjustment that is possible. A small amount of movement of adjustment screw (2) makes a large pressure change.
- Adjust the set screw and repeat the test procedures until the pressures are identical.
- Maintain the position of the set screw while you tighten the lock screw.
- Reconnect the linkage between the two manual displacement control levers.
- Stop the engine, and remove the gauges.