Transmission fluid replacment

[steamer99]

Hi All
I did a search on "transmission flush" and do understand why not to do a high pressure reverse flush, but are there any good reasons not to do the following?
Disconnect the fluid lines from the cooler and hook them up to allow the transmission pump to pump out the old fluid and draw in fresh fluid until the entire amount has been changed? This is the way that "quick lubes" do it in this area (they call it a "flush & fill), and I was thiking that it would be quicker and easier than the drain the pan and top up 3 to 4 times method.

[Huskymaniac]

Originally Posted by steamer99

Hi All
I did a search on "transmission flush" and do understand why not to do a high pressure reverse flush, but are there any good reasons not to do the following?
Disconnect the fluid lines from the cooler and hook them up to allow the transmission pump to pump out the old fluid and draw in fresh fluid until the entire amount has been changed? This is the way that "quick lubes" do it in this area (they call it a "flush & fill), and I was thiking that it would be quicker and easier than the drain the pan and top up 3 to 4 times method.

If you are filling with cheap ATF, the wasted fluid you would lose to make sure you have a complete flush wouldn't be a big deal. If you are using synthetic ATF from Mobil, Redline, Amsoil or BG you probably would want to be sure every drop you put in, stays in.

[steamer99]

She is getting all synthetic fluids at this change.

[Huskymaniac]

Then you might want to drain as much out as possible and just top it off. If you do that every 10-15K miles, you should be good to go.

[1986nate]

My thoughts, disconnect the return line, drain out what's in the pan, start the car and put it in neutral. It will turn the pump while not trying to actually engage anything. This should get just about all the old fluid out. Reconnect the return line, replace the filter, and put your nice new synth fluid in.


Edit: In thinking about this, it would probably damage the pump so don't do it.

[SVX92-97]

I just drop the pan and replace filter and gasket and refill with fresh Amsoil Synthetic