834G Wheel Dozer and 836G Landfill Compactor Electrohydraulic System Caterpillar

The torque converter stall and implement double stall test helps determine if the engine is producing the correct power output. This stall test may be used in many diagnostic procedures.

Show/hide table

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.

Machine Preparation

1. Move the machine to a smooth level location. Move away from working machines and personnel. Lower the attachments to the ground.

2. Allow only one operator on the machine. Keep all personnel away from the machine or in the view of the operator.

3. Engage the parking brake.

Stall Test

1. Shift the transmission to the NEUTRAL position.

2. Start the engine. Warm the transmission oil to normal operating temperature of approximately 74° to 85°C (165° to 185° F).

3. Lower the blade to the ground. Return the control lever to the HOLD position.

4. Fully depress the right side service brake pedal. Hold the brake pedal in the depressed position for the duration of the test.

5. In order to run the test in third speed, the transmission maximum speed must be overridden.

   Reference: Refer to the section "Transmission Override (Diagnostics)" for information about setting the transmission (ECM).

Show/hide table

NOTICE
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 speed to low idle, move the transmission control to neutral and increase the engine speed to approximately 1500 rpm to cool the oil.

6. Place the transmission control in the THIRD SPEED position.

7. Move the transmission direction switch to the FORWARD position.

8. Increase the engine speed to high idle.

9. Move the lift control lever to the Full RAISE position in order to move the lift cylinder against the stops. Hold the control lever in the Full RAISE position.

10. Allow the engine speed to stabilize. Record the engine rpm. Return the lift control lever to the HOLD position.

11. Reduce the engine speed to low idle.

12. Shift the transmission to the NEUTRAL position.

The correct torque converter stall and implement double stall speed for the 834GWheel Dozer in third speed forward is 1620 ± 80 rpm.

The correct torque converter stall and implement double stall speed for the 836G Landfill Compactor in third speed forward is 1650 ± 80 rpm.

Low stall speeds indicate a possible problem with engine performance. The stall speed should be corrected before the performance of the hydraulic system can be properly tested.

Transmission Override (Diagnostics)

Testing procedures may require shifting a machine into a specific gear in order to perform a test. The power train ECM may prevent some machines from shifting into third speed forward. The power of the engine will be reduced at third speed forward without setting the override for the transmission (ECM). This would render the diagnostic procedure ineffective. The power train ECM must be overridden in order for the diagnostics to be performed. Refer to Table 1 in order to determine the correct procedure for overriding the power train ECM.

Table 1

Machine Serial Number	Transmission Override Procedure
6GZ	4C-8195 or ET
7MZ	4C-8195 or ET
BPC	Electronic Technician (ET)
BRL	Electronic Technician (ET)

Illustration 1	g00847900

Illustration 2	g00847902
Location of the connector for Caterpillar Monitoring System and Electronic Technician (1) Connector for Caterpillar (ET). (2) Connector for Caterpillar Monitoring System.

Caterpillar Monitoring system

Refer to Illustration 1 and Illustration 2 for the location of the connector for the Caterpillar Monitoring System.

1. Connect the 4C-8195 Control Service Tool to the service connector (2) in the cab. The service connector is located on the back wall of the cab to the right of the operator's station.

2. Use the 4C-8195 Control Service Tool to enter Transmission Calibration Mode "6" via the "MODE" switch (2) .

3. Toggle the "SCROLL" switch until display reads "11 Sb0". Toggle the "CLEAR" switch until display reads "11 Sb1". The transmission should now be shifted into the THIRD SPEED FORWARD position.

4. After the test is completed, toggle the "SCROLL" switch until display reads "11 Sb0". This should set the transmission Electronic control module to the default parameter.

CaterpillarElectronic Technician

Refer to Illustration 1 and Illustration 2 for the location of the connector for the Caterpillar Electronic Technician.

1. Connect the laptop computer to the service connector (1) in the cab. The service connector is located on the back wall of the cab to the right of the operator's station.

2. Open the software program (ET). Select the appropriate "Transmission XXXX" from the "ECM Selector" menu.

3. Select the "Diagnostics" menu item from the toolbar.

4. Select the "Diagnostic Tests" menu item.

5. Select the "Override Parameters" menu item.

6. Select the "Stall Speed and Brake Test Mode Override" menu item. Set the value to "ON". The transmission can now be shifted into THIRD SPEED FORWARD.

7. The transmission override can be exited by turning the value in the diagnostic override box to "OFF". You can also exit the diagnostic override by logging out of ET.