Tranny oil change using the return line

[civic_matic_00]

Has anyone done the tranny oil change below? I usually just drain and fill from the pan. is the procedure below the proper way to flush the old fluid?

http://www.allpar.com/eek/atf.html

James Bottger wrote:

While it's much better for the transmission to change the fluid using the method in [the above] article than it is not to change the fluid at all, this method only replaces about half of the fluid in the transmission. The best thing to do is to change out ALL of the fluid, and this is also something a person can do themselves.

First, drain the fluid from the pan, just like you would using Mr. Macfairlane's procedure. Once you've replaced the filter, the pan gasket, and reinstalled the pan, you're ready for the next step.

Fill the transmission to the proper level using the proper type of transmission fluid. Then disconnect the return transmission line (the line in which transmission fluid flows from the transmission cooler back to the transmission), located near the bottom of the radiator. There's two transmission lines connected in this location, and the bottom line is usually the return line. Once the line has been disconnected, attach a clear piece of tubing to the transmission cooler, the same diameter as the transmission line, approximately 5-6 feet long, using the transmission line clamp to secure it.

Place the unattached end of the clear tube in a plastic, one gallon milk container and place it where it can be seen (like not under the car).

For the next portion of the procedure, make sure that the parking brake is set prior to continuing. Start the engine. The transmission needs to be put into "Drive" so the torque converter fluid is changed as well. Some transmissions will only circulate fluid through the torque converter only in drive. This especially applies to the electronically controlled transmissions. [Craig Sherman noted that Drive is needed for most transmissions, based on technical manuals]

After approximately 4 to 5 quarts (obviously, if it's more than 4 quarts, you'll have to turn of the engine, and fetch another milk jug) of fluid have been pumped out, you should notice a change in the color of the fluid. It should go from a brownish red color, to a bright pinkish red color. When this happens, all of the old fluid has been replaced with new fluid.

Be careful not to overfill the tranny during this procedure.

When completed, reconnect the transmission return line to the transmission cooler. Check the fluid level as you normally would, and add fluid as required.

This fluid change method is twice as good for your transmission as the method of only changing out half of the fluid is. Happy shifting!