Should I change the ATF after reaching 266ºF

[Ken2]

Where did you measure the ATF temperature?...in the sump or in the line to the cooler? If in the cooler line, OK. If in the sump, not OK.

Ease your mind. Send a sample of the fluid to a testing lab. $22.50 at Blackstone. They'll tell you what you have and you'll KNOW what to do, not just guess or take the average of our guesses. There will be testing labs in Spain, but you might have to ask around some industrial places or truck fleet shops to get the contacts.

 

[brian12]

"Most ATF can withstand normal operating temperatures of around 200 degrees F for tens of thousands of miles. But if the temperature of the fluid rises above 220 degrees F the fluid starts to break down quickly. Above 300 degrees, fluid life is measured in hundreds, not thousands of miles. And above 400 degrees, the fluid can self-destruct in 20 to 30 minutes!"
http://www.aa1car.com/library/atf.htm

I would do a drain and refill.

 

[ecco123]

Ken, the temperature is on the cooler line as it leaves the tc.

I did a "poor man analisys" with a piece of paper: I put a sample of the used ATF and some more of new ATF.

I said the ATF looked like new, but, after comparing them, it doesn't look like new at all. I didn't expect it to look the same as the oil coming out of the can, but it's quite unlike it.

It's like an orange brown color instead of the red of the new ATF. I must say also that the new ATF is not the same brand as the one in the transmission, but both are Dexron III.

Is this normal after such few miles?. Is the oil damaged or is it just the rust it pulls as it moves in the internal parts?.

I suspect I will have to change it as soon as possible. It's a pain as I have to drive for two hours and pay the man another 220€ (300 usd) for oil and filter with the machine.

Another option is to flush it myself but then I won't be changing all the fluid and the new one wouls still being contaminated with the old one, wouldn't it?

 

[unDummy]

A small percentage of old fluid contaminating the new fluid is no big deal. Even a flush machine is at the mercy of the technician and is never 100%.

$300 buys many quarts ATF and should cover maintenance for a long time if you do it yourself and pick an interval that is mileage or time based.

Just drain the old, and refill it with new ATF NOW to get some fresh ATF in there. Repeat every 10k miles until you run out of the $300 that you would have paid 'the man'.

An upgrade to a better fluid will also help make up for issues like this.

 

[ecco123]

Shouldn't I be changing the oil filter as well?

The other posibility I saw in the Amsoil website is to change all the oil without a machine, disconnecting the fluid lines of the cooler and adding oil through the dipstick as it's coming out of the cooler lines.

http://www.amsoil.com/faqs/ATF_and_Filter_Change_Procedures.pdf

Is it as easy to do as it sounds?. I don't understand why you have to disconnect both lines from the cooler as you are adding the new oil through the dipstick. Should be enought to disconnect the line that leaves the transmission to the cooler, shouldn't it?

 

[brian12]

Does your car have a drain plug on the trans pan? My corolla does and I think most japanese cars did but things have changed. If it has a drain plug drain it. Measure how much came out and then refill it with that same exact amount of fluid. If it doesn't have a drain plug you will have to find the return line to the transmission and take it off and put it in a bucket and run the car to get the fluid out. If I were you I'd change it. That fluid doesn't look quite right. And you can do several drain and fills over a period of a few hundred/thousand miles and get the majority of the old fluid out. Not that it matters if a little old fluid is still in there.

 

[c3po]

I agree with what others have said and now seeing the pic you posted of the used fluid, drain it out. I bet if you dropped the pan that trans fluid would look real nasty.