Automatic Transmission Drain and Refill

[zdkaiser]

Hello everyone.

Yesterday I did my first drain and refill on the ATF fluid on a 2007 base model.

I think I may have potentially overfilled the ATF fluid slightly, and was curious if this is going to cause problems/major issues. I have yet to drive the car, so I am unsure if it shifting differently.

Anyways, I basically drained out a little less than 1 gallon of fluid. Almost filled an entire milk jug, and I spilled a bit of it.

I added slightly less than 4 quarts of Toyota Type T-IV ATF fluid. There is about 3 oz left in the last quart.

I tested the fluid levels via the owners manual instructions. All seemed good yesterday with a warm engine. Anyways, today I checked it again with a cold engine and the fluid level is probably about an inch above the hot mark on the dipstick. I guess some of the fluid needed time to settle.

Will this be a problem? Should I drain some out?

So, given that I spilled a tiny amount when adding the fluid, I think I added about 123 or 124 oz (more or less).

Please advise. Thanks.

[Salsa Guy]

I always check it running and warm. A few OZs shouldn't be a problem. You could always take the cooler line loose and drain a little that way. Did do the torque convertor also?

[Raven]

Draining it once will only change part of the fluid and the rest of the old stuff will mix with the new. Here's my post from today on the other active thread on this subject.

You can drain and fill the tranny 4-5 times over a day or two with several miles driving between each change.. This will replace 90% plus of the fluid. Each drain will be about 4 quarts. I buy a 5 gallon pail of transmission fluid to save money.

[Salsa Guy]

The way they suggest is to change the filter and replace the fluid. Disconnect the return line from the Cooler, connect a hose to the cooler and run it in a bucket. Start the engine and add fluid while watching the draining fluid, Once you see the draining fluid clean up shutdown the engine. Reconnect the return line to the cooler. Start again and check the level, adjust as needed.

This would be best done with some help.

[zdkaiser]

Thanks everyone.

Unfortunately, none of the replies addressed my main question.

I was concerned if having the ATF fluid slightly overfilled would be a serious problem for the tranny.

I took out just shy of 1 gallon of old fluid and replaced with 124oz or so of new fluid. There is 3 oz remaining in the last quart (4 quarts total) of Toyota ATF T-IV fluid. Yesterday when the engine was cold, the dipstick was reading slightly above the hot markers (maybe an inch at most).

I do understand that I merely swapped out 4 quarts of the 7 quarts in the system. I plan on draining and refilling in about 10K miles or so. Then probably swap it out at 15K intervals. The fluid was a pretty dark, almost blood red color. I did a drain and fill at 37K miles and then again this week at 89K miles. It was due for it. I should have probably done it sooner, but everytime I checked the dipstick it still looked fairly pink. Which is kind of deceiving, as when I drained it, it was dark.

[Salsa Guy]

I always check it running and warm. A few OZs shouldn't be a problem. You could always take the cooler line loose and drain a little that way. Did do the torque convertor also?

I did answer it.

[lannvouivre]

I tested the fluid levels via the owners manual instructions. All seemed good yesterday with a warm engine. Anyways, today I checked it again with a cold engine and the fluid level is probably about an inch above the hot mark on the dipstick. I guess some of the fluid needed time to settle..

ATF must be checked with the engine running to get an accurate reading. Automatic transmissions don't just use it for lubrication, but also for pretty much every function. It shifts gears by directing the oil into channels, valves, and the pistons/clutch packs to run the output shaft at whatever direction/speed. If it is still overfull when hot and running after you do the "shift dance" where you cycle through each gear, then you may possibly consider draining it for peace of mind.

I don't *think* that it being overfull would hurt anything like it would in an engine (foaming), as I haven't personally heard of that, but I'm definitely not an expert.