If no bubbles on ATF dipstick, is fluid level acceptable?

[paulri]

After doing a d&f with ATF on my Sienna yesterday, I wasn’t able to see clearly where the exact fluid level was. What I am thinking now, is that most of the times I pulled the dipstick out, I noticed one or two bubbles (usually one) on the dipstick, near where I believe the top of the fluid is. I have two questions:

1. I know about bubbles on a motor oil dipstick, but can bubbles on an ATF dipstick be a sign that the fluid is too high?
2. If the answer to the first question is Yes, then can I simply lower the level of fluid until I don’t see bubbles any more, and call it good? Would the absence of bubbles let me know that even if the fluid is above the Hot range, it isn’t damaging the trans at all?

Yesterday was my first d&f for this round, and I can do another one this morning, being careful to put in less fluid than I drained out.

 

[demarpaint]

Bubbles can be a sign the level is too high. However your way to determine the proper level is one really bad way to check the fluid level, imo. It may or may not get you in the ballpark. There are some good YouTube videos on how to read a transmission dipstick. I'd check some of the videos out.

 

[paulri]

I've come across the info on how to do it properly--warm up the car, park it level, move it from P to L and back to P, leave engine running, pull dipstick out, clean it, insert it again, pull it out again. Its just that there is oil all over the dipstick. I did see a spot where on at least one side, the fluid either got very thin, or stopped, before resuming. This was about one inch above the hot mark, and usually the same exact spot every time I pulled out the dipstick, but it wasn't anywhere near as clear as the reading I get with my engine oil dipstick, because there was plenty of fluid above that point as well.

Bubbles can be a sign the level is too high. However your way to determine the proper level is one really bad way to check the fluid level, imo. It may or may not get you in the ballpark. There are some good YouTube videos on how to read a transmission dipstick. I'd check some of the videos out.

 

[demarpaint]

I've come across the info on how to do it properly--warm up the car, park it level, move it from P to L and back to P, leave engine running, pull dipstick out, clean it, insert it again, pull it out again. Its just that there is oil all over the dipstick. I did see a spot where on at least one side, the fluid either got very thin, or stopped, before resuming. This was about one inch above the hot mark, and usually the same exact spot every time I pulled out the dipstick, but it wasn't anywhere near as clear as the reading I get with my engine oil dipstick, because there was plenty of fluid above that point as well.

This might be of some help, it works for a lot of transmission dipsticks too. How to read hard to see dipstick Before checking the level idle the engine for about three minutes and pull the dipstick while its running, then follow the how to from the video. I found if you check the ATF level a couple of times you run AFT up the tube and get crazy readings. Now I idle the engine after driving for about three minutes and take only one reading.

 

[Kira]

Welcome to the occasional torture of checking a transmissions fluid level.
Sometimes fluid is drawn up the tube and can seem to take forever to clear. You'll get inconsistent readings when that happens.
I've gone as far as to park the car tilted on its yaw axis away from the dipstick side of the transmission just to see if I could effect a change.
Maybe high fluid reaches the dipstick tube bottom such that you cannot avoid drawing fluid up the tube.
All anyone can say is, 'keep at it'. There was actually a "knack" to learn with my car.
Still, checking the fluid often takes 8-10 tries. Sometimes it's as straightforward as can be.

 

[JeffKeryk]

Yeah, especially with fresh fluid, determining the level can be somewhat difficult. I rub the end laterally on a clean paper towel to measure the top.
Or move my thumb from the dry metal to the wet.

All good.

 

[paulri]

Demarpaint, thanks so much. That did it. I saw continuous red oil up till about an inch above the Hot mark, and then a small gap, and then more oil. That's what I'll do for ATF from now on.

This might be of some help, it works for a lot of transmission dipsticks too. How to read hard to see dipstick Before checking the level idle the engine for about three minutes and pull the dipstick while its running, then follow the how to from the video. I found if you check the ATF level a couple of times you run AFT up the tube and get crazy readings. Now I idle the engine after driving for about three minutes and take only one reading.

 

[paulri]

This is exactly what Demarpaint's linked video said to do.

Yeah, especially with fresh fluid, determining the level can be somewhat difficult. I rub the end laterally on a clean paper towel to measure the top.
Or move my thumb from the dry metal to the wet.

All good.

 

[oldcodger]

I find that you need to read both sides of the stick. On my truck one side will contact the tube and smear the fluid. If I am careful the other side will show the level. Fresh fluid is tough to see sometimes. Hold the stick so that light reflects off the fluid.

 

[demarpaint]

Demarpaint, thanks so much. That did it. I saw continuous red oil up till about an inch above the Hot mark, and then a small gap, and then more oil. That's what I'll do for ATF from now on.

You're welcome!

 

[paulri]

This new method I learned was especially helpful this afternoon, as I was able to get a good idea of the fluid level before my second drain & fill, so I calculated how much came out, and poured in 3/4 quart less. ATF level is now in the Hot range, but I'll double check tomorrow. But I like the fact that not only did I learn something new today, I was able to use it to accurately guess how much ATF I needed.

 

[MolaKule]

Just make sure it is not overfilled as that WILL cause foaming.

 

[The Critic]

This new method I learned was especially helpful this afternoon, as I was able to get a good idea of the fluid level before my second drain & fill, so I calculated how much came out, and poured in 3/4 quart less. ATF level is now in the Hot range, but I'll double check tomorrow. But I like the fact that not only did I learn something new today, I was able to use it to accurately guess how much ATF I needed.

Most likely, it is still overfilled. If you have ever monitored the A/T fluid temp on those, you will find that it takes a long time for the fluid to fully warm up. The hot range is supposed to be used when the fluid is fully warm, like >170F. This often takes 25+ miles of driving.

Your best option is to adjust the fluid level using the cold marks. Check the fluid level first thing in the morning while the trans is still cold and fill it between the cold min/max marks.

 

[paulri]

Interesting, most who I recall posting an opinion on the two different temp levels, say that the cold level is not the most accurate.

Don't get me wrong--checking cold doesn't involve any extra driving, so it is easier for me--but in your opinion that is going to give me a fairly accurate fluid level?

Most likely, it is still overfilled. If you have ever monitored the A/T fluid temp on those, you will find that it takes a long time for the fluid to fully warm up. The hot range is supposed to be used when the fluid is fully warm, like >170F. This often takes 25+ miles of driving.

Your best option is to adjust the fluid level using the cold marks. Check the fluid level first thing in the morning while the trans is still cold and fill it between the cold min/max marks.

 

[NismoNVT]

Absolutely dislike ATF dipsticks readings.

For most vehicles Cold isnt a marker of how close to full capacity the sump is, as you need to warm the atf before taking a reading. The cold level exists to confirm that you have enough ATF to even turn on the system without damage.

The hot marker is the true indicator, but that its not static. Most vehicle mfgs have a set drivecyle they want you to run before taking a gander at the hot level. However in experience the fluid level can vary by how long and how warm the ATF has been run. For example, I have seen the level after set drive cycle and it was at the Full hot level. However mid way through a highway jaunt, the fluid level had dropped. After a pit stop the next morning did the drivecycle again and the fluid level was the same as measured the night before.

I believe the best way to get a good fill level, is simply to take into the account the fluid drained during atf changes.

 

[The Critic]

Interesting, most who I recall posting an opinion on the two different temp levels, say that the cold level is not the most accurate.

Don't get me wrong--checking cold doesn't involve any extra driving, so it is easier for me--but in your opinion that is going to give me a fairly accurate fluid level?

IME with Toyota’s 5AT’s from that era, at least with the dealer fluid, filling to max cold in the morning usually gets the fluid level near perfect. The hot marks are only applicable if you can verify the fluid temp is between 158-176F. If you do not have a way of confirming the fluid temp, it’s easy to overfill.

 

[paulri]

Once I can confirm tomorrow that the fluid level is in the hot range, I'll then look at seeing what level this vehicle's cold reading is. If I can get a consistent cold reading at a certain level, that would make it easier for me to just look at that level, but right now I'm proceeding from verifying it is full by taking a hot reading, and then I'll see if how that looks when cold. But the cold sure would be quicker & easier.

IME with Toyota’s 5AT’s from that era, at least with the dealer fluid, filling to max cold in the morning usually gets the fluid level near perfect. The hot marks are only applicable if you can verify the fluid temp is between 158-176F. If you do not have a way of confirming the fluid temp, it’s easy to overfill.

 

[The Critic]

Once I can confirm tomorrow that the fluid level is in the hot range, I'll then look at seeing what level this vehicle's cold reading is. If I can get a consistent cold reading at a certain level, that would make it easier for me to just look at that level, but right now I'm proceeding from verifying it is full by taking a hot reading, and then I'll see if how that looks when cold. But the cold sure would be quicker & easier.

Take the vehicle for a long (25 mile+) drive and check the fluid level immediately after pulling it over. The fluid temp should be in the desired range at that point.

Checking when it is cold is easier to read since the fluid is more viscous.