TUBE ASSEM. 9K8236 - Caterpillar

Probable Causes of Problems in the Torque Converter
Torque converter pressure is high
Probable causes
There is a restriction inside the torque converter.
There is a restriction in an oil passage or in the oil cooler.
Torque converter inlet ratio valve (11) is stuck in the closed position.Torque converter pressure is low
Probable causes
Torque converter inlet ratio valve (11) is stuck in the open position.
Adjustment of torque converter outlet relief valve (27) is not correct.
The valve spool in torque converter outlet relief valve (27) does not move.
Pump flow or oil pressure is low. This may be caused by any of the following conditions:
The oil level is low.
There is a restriction in the oil flow circuit or a dirty oil strainer.
Oil pump failure.
Air leaks on the inlet side of the pump.
Leakage inside the transmission (worn seals around the clutch piston)
Modulating relief valve (13) is stuck open.The torque converter overheats
Probable causes
The machine is being used for the wrong application. There is too much torque converter slip, which is caused by too much load.
Incorrect transmission gear is being used for the load that is on the machine. Shift to a lower gear.
The oil level in the transfer gear case is incorrectly high or low.
The coolant level in the engine radiator is low.
The oil cooler or oil lines are restricted.
Oil flow through the torque converter is too low. This may be caused by any of the following conditions:
The torque converter inlet ratio valve (11) is bypassing too much oil flow.
Pump flow or oil pressure is low. Refer to the Problem: Torque converter pressure is low.The torque converter does not respond correctly to the left service brake pedal
Probable causes
The torque converter is in the mode for reduced rimpull (if equipped). This changes the response of the left service brake pedal.
The sensor for the left service brake pedal is calibrated incorrectly.
The left service brake pedal position sensor is faulty.
The impeller clutch solenoid or the impeller clutch solenoid valve is faulty.
There is a problem in the electrical circuit.The lockup clutch does not engage
Probable causes
The on/off switch for the lockup clutch is not in the ON position.
The on/off switch for the lockup clutch is faulty.
The lockup clutch solenoid or the lockup clutch solenoid valve is faulty.
There is a problem in the electrical circuit.The lockup clutch engages intermittently.
Probable causes
Erratic signals from the engine speed sensor or the torque converter speed sensor can cause the lockup clutch in the torque converter to cycle on and off when the lockup clutch is enabled.The impeller clutch does not engage
Probable causes
The impeller clutch solenoid or the impeller clutch solenoid valve is faulty.
There is a problem in the electrical circuit.Troubleshooting the Calibration of the Impeller Clutch
The calibration of the impeller clutch can generate error messages if a problem is encountered during calibration. The following information is used to aid in troubleshooting the problem that was based on the error message.
Table 1
Troubleshooting Information for the Calibration of the Impeller Clutch    
Error Message     Probable Causes     Possible Corrective Actions    
Torque converter output speed is low.