flushing ATF

[dklein90]

I brought my new to me 98 forester to the local Quicky Lub to see about changing the Auto trans fluid. (fluid looks brown and should be pink) They told me that on Subarus the transmision is set up in a way that all the fluid can not be replaced. All they would be able to do is take out about 4 quarts and add fresh fluid to it. A bunch of old nasty fluid with a little fresh fluid dosnt get you very far.

 

Is there any truth to this?

How can I get the old fluid out of there and new ATF in?

 

Thanks

-Dave

[the_bard]

I've heard the same... you can only drain so much of it out while it's sitting. Not sure on the exact amount, but there was a recent thread on the subject. To get as much of it out as possible, you end up doing partial changes (drain, fill, circulate... repeat).

 

There was also some thoughts on how to get the tranny fluid to circulate while you're filling and draining, all at once, to remove all the old fluid, but if I remember correctly, it involved having the fill side pressurized.

 

Anyway, do a quick search, and you ought to find something.

[Midwst]

some professional tranny guys have told me that transmission power flush may be a bad idea. Lifts gunk/debris off bottom of tranny pan and pushes throughout the tranny. Can sometimes cause a tranny to fail. Would recommend changing the fluid...drain and refill multiple times in a row, within a few days/weeks/months of each other...instead of power flush. Power flush weakened my already noisy tranny pump causing it to die faster. But it was already making noise. Would like to hear others ideas about tranny power flush.

[NorthWet]

Many/most automatics can't be drained completely because about half of the ATF will be retained in the torque converter which usually doesn't have a drain.

 

Most AT service places offer a "Power Flush" which is supposed to replace all of the fluid. I do not know whether or not your Quicky Lube offers Power Flushes or not, or whether there really is no way to Power Flush a Subaru.

[chef_tim]

I put a pint of Sea Foam Trany treatment in my 97 OB yesterday and the improvement is very noticable. I am going to have the fliud changed though too, I just want to get some "pre-cleaning" going on. Tim

[dklein90]

I think Im going to go with the draining out a little at a time idea. Im not sure if I will ever get the ATF to look pink and clean again but at least I will know that there is some good fluid in it. A few quarts every weekend should help.

[lmdew]

You can get all the fluid changed out if you pull the trans fluid hose off the radiator. You run end into a bucket and let the trans pump out a quart at a time. You do NOT want to run it dry so have two workers to do this.

 

Pull the hose, one side will pump fluid out.

Put a long hose on this side and run it to a bucket or empty gallon jug.

Fill the trans

Start the car, in a few seconds, you will have a quart of old fluid

Stop the car, service the trans

Continue until the fluid coming out the hose is fresh

Put it all back together and service the trans.

Check for leaks

Take if for a drive and check the fluid level again

Leak check one more time and your done.

 

Works for me! Perform at you own risk!

[timintc]

i did the drain and fill method recently on my 2000 legacy 93K , first time got out about 4 quarts poured the drain pan into a quart windshileld washer fluid bottle. waited bout two weeks bought a new filter and with the jack under the passenger side front tire to help me get under the car, it also allowed me to drain 6 quarts out with the filter removed. even with replacing what was drained its not all that easy to read that dipstick, tho a mechanic told me that of the two sides of a dipstick its the low side thats the accurate one. if anyone has an opinion i used valvoline max life atf and all seems to be working well two weeks afterwards, i cant think of anything more rewarding than spending an afternoon changing fluids on the subbie, but now with the differentials, crankcase and tranny done now theres hardly anything left to do