| Required Tools | ||
| Part Number | Description | Qty |
| 8T-5320 | Hydraulic Test Group | 1 |
The torque converter stall test helps determine if the engine is producing the correct power output. The torque converter stall and implement double stall test can be used in order to determine the condition of the hydraulic implement pump. This test may be used in other diagnostic procedures.
The hydraulic fan must be at maximum speed when you perform the stall test. This will ensure that there is a consistent parasitic load on the engine. The Caterpillar Electronic Technician (ET) should be used in order to set the fan to maximum speed.
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Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine. To prevent personal injury or death, perform the following: Park the machine on a smooth, level surface. Lower the work tool to the ground and engage the parking brake. Stop the engine and remove the key. Block the wheels and install the steering frame lock. |
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Personal injury or death can result from machine movement. When tests and adjustments are made to the transmission or the torque converter, the parking brake must be disengaged. To prevent movement of the machine and personal injury perform the procedure that follows. |
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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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At operating temperature the implement hydraulic oil tank is hot and under pressure. Hot oil can cause burns. To prevent possible injury, release the pressure in the implement hydraulic system before hydraulic lines or components are disconnected or removed. |
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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, "Caterpillar Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
Before proceeding to the test procedure that follows, complete the procedures:
- Testing and Adjusting, "Machine Preparation for Troubleshooting"
- Testing and Adjusting, "System Pressure - Release"
- Move the control lever to the HOLD position.
- Disconnect the hydraulic oil lines (1) and (2) from the manifold.
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| Illustration 1 | g00404399 |
Location of Hydraulic Oil Lines (front of non-engine end frame) (1) Rod end line of left lift cylinder. (2) Rod end line of right lift cylinder. | |
- Install two blocking plate assemblies from the 8T-5320 Hydraulic Test Group in the hydraulic oil lines (1) and (2) .
- Start the engine. Warm the transmission oil to normal operating temperature of approximately 49 to 65°C (120 to 150°F).
- Connect Caterpillar ET to the data link connector. The data link connector is next to the keypad. Start Caterpillar ET.
- Select "Cab Information 1". Select "Diagnostics and Diagnostic tests". Select "Override Parameters and Engine Fan Bypass".
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| Illustration 2 | g01483653 |
- Enter "0%" for the "Engine Fan Bypass Override Parameter". This should cause the fan to run at maximum speed when the engine is at high idle.
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| Illustration 3 | g01483693 |
- Release the parking brake.
- Fully depress the right side service brake pedal. Hold the brake pedal in the depressed position for the duration of this test.
- Increase the engine speed to high idle.
| NOTICE |
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To make sure that the transmission oil does not overheat, do not keep the torque converter in a stall condition for more than 30 seconds. After the torque converter stall test, reduce engine speedto low idle, move the transmission control to neutral and increase the engine speed to approximately 1500 rpm to cool the oil. |
- Place the transmission in THIRD SPEED.
- Move the transmission direction switch to the FORWARD position.
- Allow the engine rpm to stabilize. Record the engine rpm.
- Move the lift control lever to the full RAISE position. Hold the lever in this position. Allow the engine rpm to stabilize. Record the engine rpm.
- Move the lift control lever to the HOLD position.
- Reduce the engine speed to low idle. Shift the transmission to the NEUTRAL position.
- Allow the engine coolant and the transmission oil to cool. Stop the engine.
- Remove the 8T-5320 Hydraulic Test Group in hydraulic oil lines (1) and (2). Install hydraulic oil lines (1) and (2) back to the original position on the manifold.
Note: Release system pressure before you attempt to remove any pressure gauges or test equipment from the machine.
| Torque Converter Stall and Implement Pump Double Stall Speeds (1) | |||
| Machine | Minimum | Nominal | Maximum |
| 854K | 1450 RPM | 1500 RPM | 1550 RPM |
| ( 1 ) | Check the stall speed with the hydraulic fan at maximum speed. |
The torque converter stall speed should be within the minimum and maximum engine speeds that are listed in table 2.
If the double stall speed is more than 1550 rpm, the relief valve setting may be too low or the implement pump may be worn.
If the torque converter stall speed is less than 1450 rpm, the relief valve setting may be too high.