Transmission fluid?

Engine oil is checked with the indicator with the yellow handle, on the front of the engine. The transmission fill indicator is under the transmission fill cap, near the air cleaner housing. The transmission fluid is checked with the engine running in park. this guide can help

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Transmission Fluid Type

Type .................... DEXRON III or Equivalent

AUTOMATIC TRANSMISSION FLUID CAPACITY

Bottom Pan Removal (requires drain plug removal) .................... 7.0 liters (7.4 quarts)
Complete Overhaul (with existing converter) .................... 12.0 liters (12.6 quarts)
Dry .................... 14.2 liters (15.0 quarts)

NOTE: ALL capacity specifications are approximate. When replacing or adding fluids, fill to the recommended level and recheck fluid level.

Are you check the level with the car running? What was it showing before you added fluid? Check the fluid level when it is hot. Usually let it idle for a little bit. Run it through all the gears, and check fluid level again.

Are you having shifting issues? Seems you could have a leak somewhere.

If you are just changing fluid it will only take about 4 qts due to not replacing all the oil just in pan. It takes 15qts for a completely empty trnasmission

Hello,

Here is how you check the fluid level of the transmission with fluid type and capacity.

The dipstick is # 12 in the diagrams below.

4T80-E AUTOMATIC TRANSAXLE

HOW TO CHECK
Be sure to follow all the instructions here, or you could get a false reading on the dipstick.

NOTICE: Too much or too little fluid can damage your transaxle. Too much can mean that some of the fluid could come out and fall on hot engine or exhaust system parts, starting a fire. Too little fluid could cause the transaxle to overheat. Be sure to get an accurate reading if you check your transaxle fluid.

Wait at least 30 minutes before checking the transaxle fluid level if you have been driving:
- When outside temperatures are above 90° F (32° C).
- At high speed for quite a while.
- In heavy traffic - especially in hot weather.
- While pulling a trailer.
- To get the right reading, the fluid should be at normal operating temperature, which is 180° F to 200° F (82° C to 93° C).
- Get the vehicle warmed up by driving about 15 miles (24 km) when outside temperatures are above 50° F (10° C). If it's colder than 50° F (10° C), you may have to drive longer.

CHECKING THE FLUID LEVEL
Prepare you vehicle as follows:
- Park your vehicle on a level place. Keep the engine running.
- With the parking brake applied, place the shift lever in PARK (P).
- With your foot on the brake pedal, move the shift lever through each gear range, pausing for about three seconds in each range. Then, position the shift lever in PARK (P).
- Let the engine run at idle for three to five minutes.

Then, without shutting off the engine, follow these steps:
1. The transaxle fluid cap is located next to the radiator hose and below the engine air cleaner/filter assembly on the driver's side of the vehicle. After removing the engine air cleaner/filter assembly to reach the transaxle fluid cap, turn the cap counterclockwise to remove. Pull out the dipstick and wipe it with a clean rag or paper towel. Push it back in all the way, wait three seconds, and then pull it back out again.
2. Check both sides of the dipstick, and read the lower level. The fluid level must be in the cross-hatched area. If the fluid level is in the acceptable range, push the dipstick back in all the way and turn the handle clockwise. Reinstall the engine air cleaner/filter assembly.

HOW TO ADD FLUID
1. If the fluid level is low, add only enough of the proper fluid to bring the level into the cross-hatched area on the dipstick.
2. Pull out the dipstick. Using a long-neck funnel, add enough fluid at the dipstick hole to bring it to the proper level. It doesn't take much fluid, generally less than one pint (0.5 L). Don't overfill.

NOTICE: We recommend you use only fluid labeled DEXRON -III, because fluid with that label is made especially for your automatic transaxle. Damage caused by fluid other than DEXRON -III is not covered by your new vehicle warranty.

3. After adding fluid, recheck the fluid level as described under How to Check. When the correct fluid level is obtained, push the dipstick back in all the way and turn the handle clockwise.

Bottom Pan Removal (requires drain plug removal) .................... 7.0 liters (7.4 quarts)
Complete Overhaul (with existing converter) .................... 12.0 liters (12.6 quarts)
Dry .................... 14.2 liters (15.0 quarts)

NOTE: ALL capacity specifications are approximate. When replacing or adding fluids, fill to the recommended level and recheck fluid level.

This guide can help

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

You need special large equipment to do a tranny flush. Would you like the tranny fluid replacement procedures or will you be just taking to a shop to have it flushed?

The tranny cooler lines screw into the radiator, and there is a tank to cool the fluid, you will need either a new tank, or radiator. Also when the car cools off, open the radiator and check the coolant, we are looking to see if tranny fluid may have also leaked into the coolant! Radiator will run about 200-300 plus labor. Can also be just the line leaking, and that would save a boatload!

Look at the transmission cooler lines.

Sounds like the transmission cooler inside the radiator is leaking. That will let the antifreeze and transmission fluid mix. Replace the radiator, then flush and refill the transmission and cooling system. The transmission fluid in the cooling system will lead to rotted rubber hoses over time if you don't get most of it out. It's more important to get the coolant out of the transmission. A transmission flush and refill might be a good idea.

Unless the owner's manual tells you differently, the standard used to be three years or 36,000 miles. A fluid and filter change was the recommended service, and only half of the fluid drains out and is replaced. For maintenance, that is fine. If the cars sit a lot and you put on very few miles, I wouldn't worry about the three years, but you DO want to drive them periodically. As they sit the fluid will run out of the clutch packs and expose the fiber plates to air. When they dry out is when the material flakes off. When rebuilding an automatic it is even standard procedure to soak the new plates in fluid before installing them. Driving the car once every few months will keep the plates covered in fluid so they don't dry out.

If there is debris floating around in the fluid, or the fluid is burned, the damage is already done, but the system can be flushed with special equipment. That replaces all of the fluid but it won't correct the clutch plate material that has already flaked off. Usually a flush is severe overkill.