Checking transmission fluid

So I added maybe a 1/3 quart of tranny fluid. Jumped the connectors and I couldnt get the at temp check light to go on. Let it idle and see if it would turn yellow to no avail. So I went and unscrewed the overfill plug. It just started to flow out with no trickle. I srewed back in to not lose anymore. Was I not to temp so it would have just drained out?
2wd prerunner

 

For most things a higher temperature makes them expand. There are a few exceptions e.g., water when it freezes. Know anybody with a Scangauge II ? It plugs into the OBDII port. It will give you transmission fluid temp.

 

Was the engine running when you pulled the overflow plug?

 

Your ambient temp may be messing with ya, try it first thing in the morning after the vehicle has completely cooled down. Trying to get it in temp check mode screws a lot of people up mainly because they do it durning the summer when it’s warm and have previously ran the vehicle and the transmission fluid is already hot when they try to check it.

 

Watch this video....it will help with some of your questions I'm sure

https://www.youtube.com/watch?v=ej_6BZpK3gg&t=911s

 

The engine was running when I unscrewed the overflow srew. I will try it in the morning. It was never all the way cooled down. The manual pump I have is a pos. I spilled it twice and i kinks.That video kinda looked like what mine did but I screwed it back in real quick

 

Start with the Trans Fluid cool or cold.
Then do exactly as described in the DIY
https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/

The video helps you to understand the process.

 

Just completed my first ever drain and fill on mine a few weeks ago. Nothing to it. Took about 15-20min to get my transmission up to temp. It was around 60 degrees the day I completed. To pass along a tip that I picked up from another member here somewhere, put a funnel under the hood, attached to a piece of tubing, and insert into transmission fill. This worked way better than I expected, do not think I spilled a drop.

 

Well , I just tried again in the am to get into check mode on my trans fluid. The light never came on. So now that its warm should I just go ahead and unscrew the overfill plug and let any excess flow drain out?

 

Great idea, I wonder if that would work when filling the front differential. I'm getting too old to crawl around and fight with that stupid transfer pump...

 

using a funnel and a long line works fantastic for filling both diffs as well as the transfer case .

 

That’s a bummer. Personally,I would keep trying to get the temp check mode to work. That’s the right thing to do.

 

An IR temp reader is sufficient to measure the ATF temp. Aim at center of the pan. I have an UltraGauge that measures ATF temps from both ATF temp sensors and compared the reading to my IR gun - the difference was less than a degree.

 

I finally got it. I didnt understand you have to go from neutral to drive really quick. I wasnt going fast enough. The light came on steady and removed the overfill plug and it came out steady for about 3 seconds. Thanks for the help. And I will definitely use the funnel and extended hose trick to fill.