Proper way to check ATF

[riot8ap]

I have a 2001 Mazda 626 V6. I have an auxiliary transmission cooler installed, and whoever installed it didn't tighten one of the clamps. The hose popped off and sprayed tranny fluid everywhere. I got another clamp, reconnected the hose, and refilled with Dextron III through the dipstick tube.

Now my problem is the proper way to check the fluid level. My Haynes manual says to check the fluid while the car is idling. Then in another section I think it says to turn the car off.

Which is it?

Thanks!

 

[JakeR22]

Do you have the owners manual? Check that.

 

[riot8ap]

No...don't have it.

How does everyone else check theirs?

Thx

 

[road_rascal]

On my Fords it's with the engine hot and idling, and this is after I've run the trans selector through all the ranges and then into park. Are you sure your Mazda takes DexIII? I thought the later ones used Mercon V.

 

[sifan]

Do not overfill with ATF in the first place. I do not know if your ATF dip stick has two sets of high marks: one for cold, and the other for hot. Mine does.

Here is how I do to my car.

1) When the engine is cold and not running, I will fill it until the level is a bit lower than the cold high mark.
2) Start the engine.
3) Check the ATF level at the cold high mark on the dip stick while the engine is running.
4) If it is still a bit low, stop the engine and add a little more ATF without overfilling.
5) Start the engine, and drive around the neighborhood. If there is insufficient ATF, the shifting will be very sluggish.
6) Stop the car while the engine is running, and check the ATF level at hot high mark on the dip stick assuming the engine is fully warmed up.
7) Stop the engine and add a bit more ATF without overfilling if needed.
8) Start the engine and check at the hot high mark again.
9) Repeat steps 7 and 8 if necessary.

 

[Titan]

The overfilling comment makes me curious...what is so bad about overfilling an ATF unit? I have two new Subarus with ATF from the factory, and another family member has a 2000 just serviced at a dealership where they changed the ATF...and ALL THREE are overfilled on the dipstick about 1/3-1/2 inch above "full hot" mark. I've put over 15000 miles on the new ones with no leaks, no problems. Just curious!

 

[Gary Allan]

The risk of overfilling is if it gets whipped up in the rotating parts. It will aerate and become ineffective as a transmission fluid. It will compress and not allow clutches and whatnot to fully engage.

 

[JHZR2]

The problem ive had on all AT vehicles Ive had to check is that the ATF easily runs along the side, screwing up readings, and/or there is an inconsistency in level rading from one side to another.

I can't stand it, especially when there is variability in the ATF volumes listed in various sources...

JMH

 

[porcupine73]

I typically check as stated: engine idling in park, after shifting through all gears. I check cold since I find it very difficult to get a reading when warm/hot. Like Titan, I have two Subaru's too and they read easiest when cold.

 

[JustinH]

Hot in park with the ford 4r70w's.

The sticks are terrible, its tough to judge it.

 

[riot8ap]

Thanks for the replies. I agree that it is tough to see exactly what mark you are at, thats why I had the question in the first place.

 

[dwendt44]

Sort of:
Replacement owner's manuals can be found here:
http://www.factoryautomanuals.com/home.php?xid=5b758d7a8c419d9114ae20f5a649417e

Had good luck with my older Olds and Merc Topaz.

 

[Titan]

Quote:

---

The risk of overfilling is if it gets whipped up in the rotating parts. It will aerate and become ineffective as a transmission fluid. It will compress and not allow clutches and whatnot to fully engage.

---

Makes sense to me...but, my GUESS is that 1/3-1/2 inch isn't enough overfill to be subject to excessive whipping. Then again, I've never opened an auto transmission, so I don't know what the bottom of it looks like. I've had several manuals opened, but, an auto is foreign to me. I never see any foam on the stick when checking the hot fluid, if that matters...could be just excellent anti-foaming agents...I don't know.

 

[9c1]

On the GM transmissions I am familiar with (RWD models) 1/3 to 1/2 inch over full is no big deal. It all, obviously, depends on the construction of the transmission.

 

[rcy]

My 2006 Honda Odyssey is the first vehicle I've ever had that the car must be OFF to check the fluid. Specifically the manual says the engine should be at operating temperature, but not running.

 

[Earl Filter]

Some (Mitsubishis, for example) need to be checked idling in neutral. Otherwise you will NOT get a good reading. It is imperative to know what YOUR car needs to get the correct reading.