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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. |
The following procedure is used to test for parasitic load on the engine.
Note: Verify that the transmission oil is at normal operation temperature. Machines operating under normal conditions should have engine stall speeds that are within the specified range. Refer to the factory test measurements to determine the appropriate specification for the machine that is being serviced. If the machine being serviced is outside the range of engine stall speeds, the power train components should be inspected. Use the component test specifications to determine the corrective action. These ranges of engine stall speed should not be used to adjust the engine power of the machine. If engine output is suspect, the engine should be tested on a dynamometer.
The torque converter stall test helps determine if the engine is producing the correct power output. This stall test is used in many diagnostic procedures.
The parking brake must be applied when the tests are performed. Make sure that the parking brake is fully operational before you perform any tests.
The service brakes must be applied when the tests are performed. Make sure that the service brakes are fully operational before you perform any tests.
For any test that requires a specific system to be at "Normal Machine Testing Temperature", refer to the values in Table 1.
| Fluid | Temperature |
|---|---|
| Hydraulic Oil | |
| Torque Converter Oil | |
| Transmission Sump Oil | |
| Engine Coolant | |
| Test Condition | 815K | -816K- |
|---|---|---|
| Raise Double stall speed check 2F with -PTS | 2049 ± 50 RPM | |
| Raise Double stall speed check 2F without -PTS | 2085 ± 50 RPM | 2049 ± 50 RPM |
For any test that requires High or Low Idle Speed, refer to the values in Table 3.
| High Idle Speed | 2270 ± 20 RPM |
| Low Idle Speed | 800 ± 20 RPM |
- Move the machine to a smooth, horizontal location that is away from operating machines and away from personnel.
Note: Permit only one operator on the machine. Keep all other personnel away from the machine or in the operators sight.
- Move the STIC transmission direction control switch to the NEUTRAL position.
- Engage the parking brake.
- Place blocks in front of the wheels and behind the wheels.
- Lower the work tool to the ground.
Reference: For additional machine preparation information, refer to the Service Manual module Testing and Adjusting, "Machine Preparation for Troubleshooting".
| Oil at Normal Operating Temperature | |
| Transmission Oil | Torque Converter Oil |
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- Run the engine and warm the machine to operation temperatures. Engine coolant and hydraulic oil should be at normal machine testing temperatures.
Note: Warm transmission oil and torque converter oil to the temperatures listed in table.
- Ensure that the parking brake is engaged. Select manual shift mode. Shift transmission to THIRD SPEED, NEUTRAL.
- At low idle shift the transmission to THIRD SPEED, FORWARD.
- Fully place the bucket in the racked back position.
- Place engine in HIGH IDLE.
- Fully stall the lift cylinders.
- Record the stabilized engine speed that occurs when the lift cylinders stall.
- After the torque converter is stalled, move the STIC transmission direction control switch to the NEUTRAL position. Operate the engine at 900 rpm to 1200 rpm to cool the oil.
Stall speeds that are low indicate either incorrect engine performance or incorrect torque converter performance. Stall speeds that are high indicate incorrect transmission performance or incorrect performance of the torque converter. If you must repeat the test, keep the transmission in neutral and wait for 2 minutes between tests.