Hummer H2. Manual - part 2615

Fig. 7: Installing Filter Seal 
Courtesy of GENERAL MOTORS CORP. 

TRANSMISSION COOLER FLUSHING & FLOW CHECK 

CAUTION: Flushing Solution (J-35944-22) is environmentally safe, yet powerful 

enough to cut through transmission fluid to dislodge any contaminants 
from the cooler. The safety precautions on the label regarding potential 
skin and eye irritations associated with prolonged exposure are typical 

 

2004 Hummer H2 

2003-04 AUTOMATIC TRANSMISSIONS Servicing - H2

  

Preparation 

1. After the repair or replacement transmission is installed in the vehicle, DO NOT reconnect the 

transmission oil cooler pipes.  

2. Remove the fill cap (9) on the Transmission Oil Cooler and Line Flusher (J-35944-A) and fill the flusher 

tank (4) with 20-21 oz. (0.6L) of flushing solution using the measuring cup (6). DO NOT overfill.  

3. Install the fill cap (9) on the flusher and pressurize the flusher tank (4) to 80-100 psi (550-700 kPa), using 

the shop air supply at the tank air valve (9). See Fig. 8 .  

4. With the water supply valve (1) on the flusher in the OFF position, connect the water supply hose (7) 

from the flusher to the water supply at the faucet. See Fig. 8 and Fig. 9 .  

5. Turn ON the water supply at the faucet. 

precautions that apply to many similar cleaning solutions. It should be 
noted that according to General Motors, use of other non-approved fluids 
for cooler flushing can have an adverse reaction to the seals inside the 
transmission. 

NOTE:

DO NOT use solutions that contain alcohol or glycol. Use of solutions that 
contain alcohol or glycol may damage flushing equipment, transmission oil 
cooler components and/or transmission components. 

 

2004 Hummer H2 

2003-04 AUTOMATIC TRANSMISSIONS Servicing - H2

  

Fig. 8: Identifying Flushing Equipment 
Courtesy of GENERAL MOTORS CORP.

 

2004 Hummer H2 

2003-04 AUTOMATIC TRANSMISSIONS Servicing - H2

  

Fig. 9: Connecting Flushing Equipment 
Courtesy of GENERAL MOTORS CORP. 

Back Flush 

1. Inspect the transmission oil cooler pipes for kinks or damage. Repair as necessary.  

2. Connect the transmission oil cooler and line flusher to the transmission oil cooler feed bottom connector. 

Use the Cooler Flushing Adapter (J 35944-200), if required.  

3. Clip the discharge hose (5) onto the transmission drain container. See Fig. 9 .  

4. Attach the flusher to the undercarriage of the vehicle with the hook provided and connect the flushing 

system feed supply hose (3) from the flusher to the top connector transmission oil cooler return pipe. Use 
the cooler flushing adapter, if required.  

5. Turn the flusher water supply valve (1) to the ON position and allow water to flow through the 

transmission oil cooler and pipes for 10 seconds to remove any remaining transmission fluid. If water 

 

2004 Hummer H2 

2003-04 AUTOMATIC TRANSMISSIONS Servicing - H2