Oil Cooler Flushing and Flow Test
Automatic Transmission Oil Cooler Flushing and Flow TestTools Required
^ J35944-A Transmission Oil Cooler Flusher
^ J35944-22 Transmission Oil Cooler Flushing Fluid
^ J45806 Cooler Flushing Adapter
^ Measuring cup
^ Funnel
^ Water supply, hot water recommended
^ Water hose, at least 16 mm (5/8 inch) ID
^ Shop air supply, with water/oil filters, regulator and pressure gage
^ Air chuck, with clip if available
^ Oil drain container
^ 19 L (5 gal) pail with lid
^ Eye protection
^ Rubber gloves
GM studies indicate that plugged or restricted transmission fluid coolers and pipes cause insufficient transmission lubrication and elevated operating temperatures which can lead to premature transmission wear-out. Many cases could have been prevented by following published procedures for transmission fluid cooler flushing and flow checking. This procedure includes flushing and flow checking the auxiliary transmission fluid cooler, if equipped. GM requires that transmission fluid cooler flushing and flow checking be performed whenever a transmission is removed from the vehicle for service within warranty, including:
^ Goodwrench SRTA
^ Major overhaul
^ Torque converter replacement
^ Fluid pump replacement
Only GM Goodwrench DETHRONE III automatic transmission fluid should be used when doing a repair on a GM transmission.
Flow Test Procedure
Notice: Do not use solutions that contain alcohol or glycol. Use of solutions that contain alcohol or glycol may damage the J35944-A, oil cooler components and/or transmission components.
1. During the installation of the repaired or replacement transmission, do not reconnect the fluid cooler pipes.
2. Install a discharge hose to the fluid cooler return pipe.
3. Clip the discharge hose onto the empty oil drain container.
4. Connect the fluid cooler feed pipe to the transmission fluid cooler feed connector on the transmission.
5. Confirm that the transmission is filled with automatic transmission fluid.
6. Start the engine with the transmission in Park range and run for 30 seconds after fluid begins to flow from the discharge hose. A minimum of 2 quarts (1.9 Liters) must be discharged during this 30 seconds run time.
^ If the fluid flow meets or exceeds 2 quarts (1.9 Liters) in 30 seconds, the fluid cooling system is functioning properly. Connect the fluid cooler return pipe to the transmission
^ If fluid flow is less than 2 quarts (1.9 Liters) in 30 seconds, disconnect the fluid cooler feed pipe from the transmission and perform the following Cooler Flushing Procedure:
Cooler Flushing Procedure
Important: The flushing fluid, J35944-22 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 precautions that apply to many similar cleaning solutions. It should be noted that according to GM, use of other non-approved fluids for cooler flushing can have an adverse reaction to the seals inside the transmission.
Preparation
1. Remove the fill cap on the J35944-A and fill the flusher tank with 0.6 Liters (20 - 21 ounces) of J35944-22 flushing solution using the measuring cup. Do not overfill.
2. Install the fill cap on the J35944-A and pressurize the flusher tank to 550 - 700 kPa (80 - 100 psi) using the shop air supply at the tank air valve.
3. With the water supply valve on the J35944-A in the OFF position, connect the water supply hose from the J35944-A to the water supply at the faucet.
4. Turn ON the water supply at the faucet.
Back Flush
1. Connect the fluid cooler feed line to J45806. Connect the J35944-A discharge hose to the J45806.
2. Clip the discharge hose onto the fluid drain container.
3. Connect the fluid cooler return pipe to J45806. Attach the J35944-A to the undercarriage of the vehicle with the hook provided and connect the flushing system feed supply hose (3) from the J35944-A to the J45806.
4. Turn the J35944-A water supply valve (1) to the ON position and allow the water to flow through the fluid cooler and pipes for 10 seconds to remove any remaining transmission fluid. If water does not flow though the fluid cooler and pipes, the cause of the blockage must be diagnosed and the plugged component must be repaired or replaced. Continue with the cooler flushing and flow check procedure once the blockage is corrected.
5. Turn the J35944-A water supply valve (1) to the OFF position and clip the discharge hose (5) onto a 5 gallon (1 9.0L) pail with a lid, to avoid splashback.
Important: Flushing for approximately 2 minutes in each cooler line direction will result in a total of about 30 - 37 Liters (8 - 10 gallons) of waste fluid. This mixture of water and flushing fluid is to be captured in a 19 Liters (5 gallons) bucket or similar container.
6. Turn the J35944-A water supply valve (1) to the ON position and depress the trigger (8) to mix cooler flushing solution into the water flow. Use the clip provided on the handle to hold the trigger (8) down. The discharge will foam vigorously when the solution is introduced into the water stream.
7. Flush the fluid cooler and pipes with water and solution for 2 minutes. During this flush, attach the shop air supply 825 kPa (120 psi) to the flushing system feed air valve (2) located on the J35944-A for 3-5 seconds at the end of every 15-20 second interval to create a surging action.
8. Release the trigger (8) and turn the J35944-A water supply valve (1) to the OFF position.
Forward Flush
1. Disconnect both hoses from the J45806 and then connect them to the opposite fitting. This will allow the fluid cooler and pipes to be flushed in the normal flow direction.
2. Repeat steps 6 and 7 of the BACK FLUSH procedure.
3. Release the trigger (8) of the J45806 and allow water only to rinse the fluid cooler and pipes for 1 minute.
4. Turn the J35944-A water supply valve (1) to the OFF position and turn OFF the water supply at the faucet.
5. Attach the shop air supply to the flushing system feed air valve (2) on the J35944-A and blow out the water from the fluid cooler and pipes. Continue until no water comes out of the discharge hose (5).
Flow Test
Important: The flow testing procedure must be performed after the flush to ensure that all flushing solution and water is removed from the fluid cooling system.
1. Disconnect both hoses from the fluid cooler pipes. Connect the fluid cooler feed pipe to the transmission, normal flow.
2. Connect a discharge hose to the fluid cooler return pipe.
3. Clip the discharge hose onto the empty fluid drain container.
4. Confirm the transmission is filled with automatic transmission fluid.
5. Start the engine with the transmission in Park range and run for 30 seconds after fluid begins to flow from the discharge hose. A minimum of 2 quarts (1.9 Liters) must be discharged during this 30 second run time.
6. If the fluid flow meets or exceeds 2 quarts (1.9 Liters) in 30 seconds, the fluid cooling system is functioning properly. Connect the fluid cooler return pipe to the transmission.
7. If the fluid flow is less than 2 quarts (1.9 Liters) in 30 seconds, disconnect the fluid cooler feed pipe from the transmission and perform the following Cooler Flushing Procedure.