Personal injury or death can result from sudden machine movement. Sudden movement of the machine or release of air pressure or oil pressure can cause injury to persons on or near the machine. To help prevent possible injury before testing and adjusting any air system or hydraulic system, perform the procedure in the Testing and Adjusting, "General Information" section. |
Illustration 1 | g00376933 |
(1) Torque converter outlet relief valve (AA) Pressure tap for torque converter outlet pressure |
This test will show the following conditions if the conditions exist:
- The torque converter operates correctly.
- Torque converter outlet relief valve (1) is correctly set.
Procedure
- Install the 9U-7400 Multitach on the engine. The 9U-7400 Multitach can measure the engine rpm by using either the photo pickup and reflective tape, a magnetic pickup, or a tachometer generator.
Note: The Electronic Control Analyzer Programmer (ECAP) or the Electronic Technician (ET) can be used instead of the multitach.
- At pressure tap (AA), connect a hose to the nipple. Connect a 8T-0854 Pressure Gauge (1000 kPa (145 psi)) to the hose.
- Start the engine. Run the engine at the low idle rpm in NEUTRAL.
- The drive wheels must not turn during a stall test. Be certain that the air pressure is at the normal pressure for operation. Engage the parking brakes and the service brakes.
Note: If the brakes do not keep the machine from moving, put the machine against a solid object that will not move.
- Be certain that the oil is at 82° to 138°C (180° to 250°F).
- Move the transmission control to the REVERSE position.
- Slowly increase the engine rpm to the maximum governor setting. The machine will try to move.
- The engine rpm must be 1715 ± 65 rpm with the torque converter in a stall condition.
- The pressure on the gauge must be 345 to 552 kPa (50 to 80 psi).
- When this test is complete, put the transmission control in NEUTRAL. Stop the engine. Remove the test equipment.
NOTICE |
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Do not keep the torque converter in a stall condition for long periods of time. Damage could occur in the torque converter, the engine, and the brakes. |
Problem: The engine speeds are out of specification.
Probable Cause
Illustration 2 | g00336118 |
Engine information plate |
- The specifications may have changed. Refer to the engine information plate in order to see the performance specification for the engine. Refer to Microfiche, SBFY1109, "Fuel Setting" in order to verify the specifications for the engine speeds.
- Refer to the engine system Electronic Troubleshooting, SENR5597, "P-312 Can Not Reach Top Engine RPM" for problems that involve the engine.
- The torque converter failed.
Problem: The high idle rpm is correct, but the stall speed is too high and the torque converter outlet pressure is correct.
Probable Cause
- The torque converter failed.
- The engine has too much power.
Problem: The torque converter outlet pressure is too low, and the oil gets too hot during normal operation.
Probable Cause
Perform the test in the Testing and Adjusting, "Relief Valve (Torque Converter Inlet) Pressure - Test and Adjust".
Problem: The torque converter outlet pressure is too low.
Probable Cause
Perform the test in the Testing and Adjusting, "Relief Valve (Torque Converter Inlet) Pressure - Test and Adjust".
Illustration 3 | g00287213 |
(1) Outlet relief valve (2) Spacers |
Chart of Spacers for the Outlet Relief Valve (1)     | ||
Pt. No. for Spacer     | Thickness     | Change in Pressure     |
5M-9624 Spacer     | 0.25 mm (.010 inch)     |
5 kPa (0.73 psi)     |
5M-9623 Spacer     | 0.90 mm (.035 inch)     |
18 kPa (2.6 psi)     |
( 1 ) | Before an adjustment is made, be certain that the valve spring is not weak or broken. |
Problem: The torque converter outlet pressure is too high, and the oil temperature is not too hot.
Probable Cause
The setting of the outlet relief valve is too high. Remove spacers (2). Refer to Table 1.
Problem: The torque converter outlet pressure is correct, and the oil gets too hot during normal operation.
Probable Cause
Refer to the Testing and Adjusting, "Brake Oil Overheating Troubleshooting".