Information on Transaxle Oil Cooler Flushing Procedure for VTi(VT25E) Transaxles

This bulletin is being updated to add model years and change a special tool reference in Step 10. Please discard Corporate Bulletin Number 03-07-30-022 (Section 07 - Transmission/Transaxle).

The purpose of this bulletin is to provide updated service information regarding transaxle oil cooler flushing for VTi transaxles. The VUE VTi transaxle cooler lines contain a temperature sensitive bypass valve. This valve prevents the flushing of the oil cooler using the existing oil cooler flushing adapters. In order to flush the VUE VTi transaxle, it is necessary to make two adapter lines and fitting from the existing oil cooler lines. After performing a transaxle oil cooler flush, new oil cooler lines must be installed. This bulletin provides the procedure for creating the two adapter lines and the fitting as well as the oil cooler flushing procedure.

1. Position the vehicle on hoist and raise the vehicle. Refer to Lifting, Jacking and Support Points in the General Information section of the Saturn VUE Service Manual or SI.
2. Drain the transaxle fluid. Refer to Transaxle Fluid Replacement in the VT25-E On-Vehicle section of the Service Manual or SI.
3. Remove the transaxle oil cooler lines from the transaxle and the oil cooler.
4. Install the oil cooler lines into a vise and cut the two lines as shown in illustration. (The cooler end of the oil cooler lines will be used in later steps. Discard the transaxle end of the oil cooler line assembly.)

Important: A 5/16 in (0.79 cm) outside diameter brake pipe must be obtained from a local parts supplier to perform the cooler flush procedure.

5. Cut two 6 in (15.22 cm) pieces of 5/16 in (0.79 cm) outside diameter brake pipe.




Important: To aid in sliding the smaller diameter hose over the cooler line pipes, lubricate the oil cooler lines with liquid soap.

6. Install a 6 in (15.24 cm) piece of 5/16 in (0.79 cm) inside diameter rubber hose to the cut end of each cooler line and secure with hose clamps.
7. Flare one end of each piece of the cut brake pipe.
8. Install a flare nut over each piece of the cut brake pipe.



9. Slide the end of the rubber hose connected to the oil cooler line over the non-flared end of the cut brake pipe. Secure with a hose clamp. Perform the same procedure for the second piece of hose/cooler line combination and cut brake pipe.
10. Using the J35944-13 measuring cup, fill the oil cooler flush tool tank with 21 oz (621 ml) of Kent-Moore J35944-22 Biodegradable Flushing Fluid.
11. Secure the cap on the tank and pressurize the tank with shop air to 80-120 psi (551-827 kPa).
12. Attach the discharge hose to the oil cooler pipe assembly that connects to the top fitting of the oil cooler. Clip the opposite end to an approved container.
13. Hang the tool under the vehicle and attach the pressure hose from the flushing tool to the remaining oil cooler pipe assembly.
14. With the water valve off, attach the water hose to the water supply (hot water, if available). Turn on the water supply.

Important: If water does not flow through the oil cooler, it is completely plugged and must be replaced.

15. Turn the water valve located on the cooler flushing tank ON to allow water to flow through the oil cooler for 10 seconds.
16. Depress the trigger on the cooler flushing tank. Slide the holding clip over the trigger and flush the cooler for two minutes. While flushing the cooler, attach an air supply to the air valve on the plumbing of the flushing tool for five seconds at 15-20 second intervals to create a surging action to help clean the oil cooler.
17. After flushing for two minutes, turn the water valve on the flushing tool OFF and release the trigger.
18. Swap connections at the tool flare fittings, attaching the discharge hose to the lower cooler fitting and the pressure hose to the upper cooler fittings.
19. Repeat Steps 15 and 16.
20. After flushing for two minutes, release the trigger and allow the water to flow through the oil cooler assembly for one minute.
21. Turn off the water valve on the flushing tool and turn off the main water supply.
22. Attach the air supply to the air valve on the plumbing of the flushing tool (not the tank valve) and dry the system out with shop air for two full minutes, or longer if required. The system is dry when no more moisture is visible in or leaving the discharge hose.

Important: Debris may be trapped within the bypass valve of the cooler lines. Therefore, replace the cooler lines any time a transaxle is replaced or repaired for a condition that may generate debris from internal damage.

23. Install the new oil cooler lines, P/N 22724408, to the oil cooler and transaxle.
24. Add transaxle fluid and inspect the level according to the Transaxle Fluid Level Checking Procedure in the VT25-E section the Service Manual or SI.

For vehicles repaired under warranty, use: