Tranny oil change using the return line

[civic_matic_00]

Originally Posted by archangel

Not the way to do it!
The automatic transmission cooler lines only bypass cool, so some of the fluid is used to power the trans, and some goes to the cooler so after a while you will have some new fluid coming out with some of the older fluid, and at a point you will be getting as much old fluid as new fluid.

The only way to do it and insure that all the fluid is changed, is to drop/drain the pan and change the filter,then turn the flywheel until the torque converter drain plug is on the bottom and remove the plug to drain the converter.
Then reinstall the pan and converter drain plug and fill it 1/2 way with fluid, start the engine and add all but the last two quarts, check for leaks, then check the level and add some again and again until you get to the cold full level.

Yeah, a small amount will remain here and there just like changing motor oil, but that's the best, and the only "proper" way to do it.

maybe for those tranny's that have a pan. mine doesn't (civics auto tranny's don't have them, I don't know about manual tranny's).

well, if it won't get all of the old oil out, it may get most of the old oil out which is a lot better than just doing it from the drain.

[COMP]

don't do it

[cmhj2000]

This procedure works very well and to be frank is even suggested in some factory service manuals.

It's referred to as the poor mans flush. I've done it many times over the past 30+ years for friends, family, neighbors, customers and on my own equipment.

No special tools are needed but it works best if you have a helper. Have the helper work the ignition switch to avoid running the pump dry and to avoid pumping excess fluid while you monitor the fluid color change during the expulsion process.

[smay665949]

Go for it, I have followed this procedure from other sources with sucess. Just make sure you are adding oil as fast as it is comming out!

[shatto]

I'm cheap and I don't like getting dirty any more, so I have my mechanic Dex, hook up the reverse-flush machine and change fluid that way. That covers replacing all the fluid in the transmission and torque converter. Yes, the internal transmission filter does occasionally need replacement and maybe the bands should be checked, so I go to my transmission shop for that.
How often? In 623,000 miles on the same transmission; three filters, one band adjustment. Reverse flush at three times the manufacturers recommended change, which is how long Amsoil ATF is good for.
However, the ATF now has 100,000 miles on it and oil analysis said it was still good.

[theholycow]

Originally Posted by shatto

How often? In 623,000 miles on the same transmission; three filters, one band adjustment. Reverse flush at three times the manufacturers recommended change, which is how long Amsoil ATF is good for.

...and people say that automatic transmissions are breakage-prone, short-lived, or weak.

[Jay2TheRescue]

The old ones were, especially because in the old days most people didn't service the transmission at all until it started giving them problems. If you buy a vehicle with a modern automatic and maintain it well it will last a long time. My truck is 10 years old and has 150,000 miles and I have no problems with the transmission. It doesn't even leak. I remember back in the 70's and 80's if an automatic lasted that long they all leaked. I remember my old 1980 Bonneville wagon towards the end (180,000 + miles) would take 1 Qt of fluid per tank of gas.

-Jay

[COMP]

Originally Posted by shatto

I'm cheap and I don't like getting dirty any more, so I have my mechanic Dex, hook up the reverse-flush machine and change fluid that way. That covers replacing all the fluid in the transmission and torque converter. Yes, the internal transmission filter does occasionally need replacement and maybe the bands should be checked, so I go to my transmission shop for that.
How often? In 623,000 miles on the same transmission; three filters, one band adjustment. Reverse flush at three times the manufacturers recommended change, which is how long Amsoil ATF is good for.
However, the ATF now has 100,000 miles on it and oil analysis said it was still good.

what kinda car is this ??? are those city miles ?

[Jay2TheRescue]

I have never trusted leaving the filter in after a flush. I always pay extra for them to change the filter & gasket.

[add|ct]

So, with my Stratus I would make sure to top off first after replacing filter; then proceed to change out old fluid via the return line by allowing the pump to take in new fluid while the old drips into a container where I've detached the return line?

If that's true that leads me to the following. Apparently, I should have the park brake applied/wheels blocked(someone depressing the breaks as well) while in "D" while I'm doing this process. Then, once I see clear fluid, have that person turn the car off > reconnect hoses at cooler return line in question > but proceed to check fluid level/top it off while hot or cold?

I think I should get the car to operating temp right after the filter change/fluid top off, doing this before proceeding to detach the return line and doing the 'flush' described. Aside from finding level ground, what temp is best to top the fluid off? Do you add fluid cold and check the level after hot etc.?