To check the transmission fluid, start the vehicle, park on a level surface, use the parking brake, shift through all gears and then put the vehicle in park, remove the transmission dipstick and clean it completely, return the dipstick and remove it again and then check the level of the fluid in the "COLD" area. To get an accurate reading, the vehicle must be running when checking the transmission fluid.
It is important to ensure that there is always adequate transmission fluid. Transmission fluid leaks are a very common problem and regularly checking the fluid is the easiest way to determine if a leak is present. If transmission fluid is low, symptoms can include slow shifting and gear slippage. Checking the transmission fluid also allows the vehicle owner to detect cross-contamination, an issue in which radiator coolant mixes with the transmission fluid. If this problem occurs, the vehicle owner must flush and refill the transmission completely.
When adding transmission fluid, it is critical to do it very carefully. Removing excessive fluid is a difficult task that vehicle owners must avoid. Pour the fluid slowly and stop every couple of seconds to check the level. Continue doing this until there is adequate fluid.