How to check automatic transmission fluid?

What is automatic transmission fluid?

Automatic transmission fluid (ATF) is the fluid used in vehicles with automatic transmissions. It is usually red or green.

Why check the automatic transmission fluid level?

Automatic transmission fluid is the lifeblood of the transmission. The fluid produces the hydraulic pressure needed to operate the transmission. It also cools and lubricates the transmission. When the fluid level is low, the pump may draw air into the system. Air in the hydraulic system interrupts the proper flow of automatic transmission fluid. Damage can occur very quickly when transmission fluid is low.

How to check automatic transmission fluid level?

For transmissions with a dipstick, the procedure is the same as described for normal transmission fluid.
Many Fords, Toyotas, GMs and other vehicles no longer have an automatic transmission dipstick for checking the fluid level. Automakers are eliminating automatic transmission dipsticks. Newer transmissions are far more complex than older models and the transmission fluid levels are far more critical. Special procedures are required to check the automatic transmission fluid level in these models.

If you want to go further, learn how to change automatic TRA

1. Drain the transmission fluid: First, disconnect the cooling line running from the transmission to the radiator. Connect a piece of rubber tubing to the pipe and place the free end of the tube in an empty container. Start the engine and let it idle. Transmission fluid should flow out of the cooling line and into the container. As soon as the fluid stops flowing, turn off the engine. You can then reconnect the cooling line to the radiator.
2. Remove the bolts holding the drain oil pan to the bottom of the transmission.
3. Clean the drain pan with transmission fluid.
4. Replace the filter.
5. Replace the gasket.
6. Replace the pan: Once the filter and gasket are in place, put the pan back on the transmission. Hand-tighten the bolts for the first few turns so that you don't strip the threads. Then use a torque wrench to finish tightening the bolts. Do not to overtighten the bolts or you will damage the threads in the transmission and dent the pan.
7. Fill with automatic transmission fluid: Dexron III ATF is the most common, but refer to the owner's manual to choose the appropriate automatic transmission fluid. Check the amount as well.