Trans Fluid slow leak, can I just add more fluid temporarily?

Car is 2000 Corolla CE with 62k miles with 4-spd auto. About 7 months ago, I had a problem with my transmission where it would get stuck after taking a sharp corner and coming to a dead stop fast. The torque convertor would stay engaged with the engine for a couple of seconds but would not produce any power output if the gas pedal is pressed. Changing the transmission fluid fixed the problem (I believe when I checked it then, it was dry).

After 7 months, I now have the same problem again. I checked the ATF dipstick and it appears to be very dry (after a 15min drive, I checked it while it was in Park gear). There was no fluid on the dipstick.

My guess is there is some sort of slow leak (Underneath the car looks clean, no spills on driveway). Anyways, for now, I’d rather add more fluid than deal with the slow leak. I always make sure to change the trans fluid once every year so I don’t think adding more fluid temporarily is a problem.

Can I just add a quart of Dex III through the dipstick hole? I don’t have the manual but I believe this corolla uses DEX III so I will be adding this atf:

It’s not Toyota brand (It’s advanced auto shop brand)…hopefully it is ok?

Yes it’s OK to add fluid through the dipstick hole. Just be sure Dexron lll is recommended. That surprises me.

Sorry, couple of more questions.

Should I add while the car is running? I put the stuff in and check the dipstick correct on the “cool” marking on the dipstick?

That year still uses DexIII. Add fluid with the car in park with the engine runing and at normal temperature. I would have the car inspected as soon as you can, running the transmission while it is low on fluid will result in it failing early.

The car doesn’t have to be running but can be while you add it. However, the checking procedure varies with different cars. You would have to check the owners manual, which you don’t have.

Forgot to add it needs to be on a level surface and fill it so the fluid is in between cold and hot.

An automatic transmission can be damaged in seconds if the fluid is excessively low so don’t be surprised if at some point in the future the transmission goes south.

If there are no fluid leaks underneath the car then you need to check the radiator coolant. It it’s mucky looking it could be that the transmission fluid cooler inside the radiator is leaking and allowing fluid to mix with engine coolant.
By the same token, engine coolant in the transmission will also take out a transmission.

I believe that car uses a separate cooler for the tranny, but I absolutely agree that this problem needs to be fixed. If it’s a cooling line or the tranny radiator, it could suddenly hemorrhage and the tranny would totally destroyed immediately.

To the OP: understand that the fluid does much more than simply operate the hydraulics to shift the gears, it’s also the tranny’s only coolant and a lubricant. It doesn’t have the ability to leave a good film on the parts if it’s lost, like gear oil does, and if it’s lost the heat immediately starts to build. Lose the oil and you lose the tranny. A leak that’d cost a few hundred to fix will instantly become a new tranny for a few thousand… and the leak will still have to be fixed.

Where do you think the trans leak is most likely? Could it be the CV axle input seals?


Should I try adding a Trans-X stop leak additive?

I agree with the comments above to investigate this now, not later.

I’m afraid I don’t understand why you let the level get so low, especially the second time when you knew there was an ongoing problem. You likely did some damage to your transmission here, which could end up costing you a lot of money. I suggest that you check your fluids more often in the future.

Inner CV joint seals would leak fluid from the differential which I think is separate on this car. Definitely confirm there is no trans fluid getting to the radiator or coolant reservoir.

Axle seals and trans pan leaks are the most common.

Wow this is going to sound very incompetent…

I forgot the funnel so I tried to makeshift with a styrofoam cup and ended up spilling some of the fluid over the rubber hoses and some got on my skin too.

The ATF bottle has warnings against getting it on your skin…do you think it could be a problem?

A possible irritant, but you’ll live your normal lifespan.
The rubber hoses might not fare as well. You might want to change them. Or at least not be surprised if they start to squeal.

Ok, so I got a funnel and added 0.8 quarts and can confirm problem is fixed.

However, I still have trouble reading the dipstick. Can someone look at the images and tell me if the level is correct?

Both were taken after cycling through the gears and after a 15 minute drive (engine is hot). It is around 38 degrees outside but the engine is hot because the rad fans turned on.

@ the same mountain bike. - Squealing hoses?

Edit: I’m sure the same mountain bike meant that if you got fluid on the belts they would squeal. If it was just on the hoses as stated just wipe them with a rag. As far as getting fresh transmission fluid on your skin just wash your hands with soap or better yet use dish detergent. No harm will come.

It’s really hard to tell from the picture. It appears to be just below the lowest notch. If so it could use a little more. I assume the bright red at the bottom is just a drop that collected at the bottom due to gravity when pulling the dipstick out.

You need to add more. The trans fluid needs to be inbetween the two notches labeled HOT. You’re below the first notch for COLD it appears.

Busted knuckles is correct you are still a bit low. It also helps to wait for a minute or two after adding the fluid, this helps the fluid drain off the fill tube and makes the stick easier to read.