Automatic Transmission Fluid - Corolland: the Toyota Corolla Forums

Hi,

I have a 2000 Corolla with about 81K miles on it. Today when I went to get the usual oil change, the mechanics told me that ATF has gone badly. It's brown in color. I was surprised to find that out, b/c just half year ago, when I asked mechanic to check, and everything was fine then. I forgot when is the last time I changed ATF, might have been 30K miles ago, but I've been quite cautious and ask mechanics to check ATF every 6 months or whenever I got a oil change job done.

1. Can ATF gone badly within half year, especially only 2000 or so miles add on to the car since it was last checked?

2. I read few articles about how brown color ATF is damaging the transmission? What kind of damage is possible? Should I just pray that those damage didn't or will not happen? Any suggestions about going forward to maintain good transmission?

3. Mechanics told me that they tried to drain as much fluid out as possible, but its' possible that there are still some left in the system. Therefore I might have to go back and drain one or two times to make sure the fluid is the nice pinkish red color (kinda like cranberry juice color). Is it true?

4. How often should ATF be flushed and added? Or it all really depends on driving conditions?

Thank you in advance for your help.

Hi,

It sounds like something definitely happened with your transmission since your last scheduled maintenance! I believe that dark colored ATF fluid indicates an overheating condition inside your transmission. Any heavy towing, or excessive wheel spin, (like trying to get unstuck from a snowbank, for example) could possibly cause the ATF fluid to turn brown. Does it have any kind of burnt odor, or are their any small particles in the fluid?

There are two ways to change transmission fluid as far as I know.

First, they drop the pan and let most of the fluid run out. The only problem with this method is they can't get the fluid out of the torque converter and that's why you are being advised to have this done more than once. Then, they will install a new filter and pan gasket and put it back together. This method will change only about 2/3 of your transmission fluid, but, you will have a new filter.

Another newer method is that they don't drop your transmission pan, but, instead, they power flush and/or vacuum your transmission fluid out of the system without opening the transmission up and replace virtually all of your ATF fluid. The tradeoff is that they don't change the transmission filter with this method.

So, the choice is yours. I guess you could have BOTH methods done starting with the newer method first, in order to achieve your objective of having really clean transmission fluid once again, but, I think that you should also make an effort to find out what really caused it to turn dark in the first place.......

By the way, I am not a mechanic, I am just sharing my own past experiences with transmission servicing from my own past.

Hope this helps,

Regards,

timkedz

Thanks, timkedz!

I'll ask mechanics tomorrow if there was any odor. He didn't mentioned and when I saw the color the he dip onto a white clothes, it was more like a lightly brown color. not sure if that makes a difference.

Thanks, timkedz!
I'll ask mechanics tomorrow if there was any odor. He didn't mentioned and when I saw the color the he dip onto a white clothes, it was more like a lightly brown color. not sure if that makes a difference.

yes ,a light brown color is not too bad as long as the trans is not burnt.dark red/brown with burnt smell is much worse.

Find a shop who has a b-g transmission flush machine.not winns either. They will use b-g quick clean and run the motor for a little while. tell them to let it set for at least and hour afterward. then have them exchange fluids with whatever proper fluid they use or get them to purchase toyota fluid or synthetic and add b-g seal conditioner.It takes 10-20 quarts for a full flush. I did this to my sienna at 130,000 because it was starting to shift funny and it rescued my transmission. Has been perfect since.My cost was just over $100. well worth it.