Hummer H3. Manual — part 729

Fig. 17: Identifying Black Supply Hose And Clear Waste Hose
Courtesy of GENERAL MOTORS CORP.

1. Disconnect the supply and waste hoses from the vehicle cooler lines. Reverse the supply and

waste hoses to provide a normal flow direction.

2007 Hummer H3

2007 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - H3

Fig. 18: Setting Main Function Switch To FLUSH Position
Courtesy of GENERAL MOTORS CORP.

2. Turn the main function switch to the FLUSH position and allow the machine to operate for

30 seconds.

Flow Test

2007 Hummer H3

2007 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - H3

Fig. 19: Setting Main Function Switch To FLOW Position
Courtesy of GENERAL MOTORS CORP.

1. Turn the main function switch to the FLOW position and allow the oil to flow for 15

seconds. Observe and note the flow rate. This is the TESTED flow rate.

2. Compare the TESTED flow rate to the MINIMUM flow rate information previously

recorded.

If the TESTED flow rate is equal to or greater than the MINIMUM flow rate
recorded, the oil cooling system is functioning properly. Perform Code Recording

IMPORTANT: If the flow rate is less than 0.5 gpm, the LCD displays an

error message. Refer to the appropriate troubleshooting
section of the operation manual.

2007 Hummer H3

2007 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - H3

Procedure.

If the TESTED flow rate is less than the MINIMUM flow rate previously recorded,
repeat the back flush and forward flush procedures.

3. If the TESTED flow rate is less than the MINIMUM flow rate after the second test, perform

the Code Recording Procedure.

1. Replace the transmission oil cooler.

2. Connect the supply and waste hoses to the cooler lines in the normal flow direction.

Perform the Flow Test.

3. Perform the Code Recording Procedure.

Code Recording Procedure

Fig. 20: Setting Main Function Switch To CODE Position
Courtesy of GENERAL MOTORS CORP.

1. Turn the main function switch to the CODE position.

2007 Hummer H3

2007 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - H3