As a human I do not have a "torque converter." Care to add more words to this strange question? Cars have torque converters that are part of the machine that changes the energy generated by the up/down motion of pistons attached to a cam shaft that produces a rotary motion that is connected to the wheels of a car via a transmission. Torque. A rotary motion. To convert. To change direction of a force. A torque converter, therefore. converts torque. Since transmissions use hydraulic fluid, any replacement of that fluid shall lead to failure. Why do you ask? Did you crash into a river, stream, swimming pool, a victim of a flood, vandalism, a drunken stated that forced to add water into the transmission, etc.? Oh, the grammar lesson continues. "What could happen when water is placed into the transmission of a (name year, make and model of the vehicle in question)?"

Hi If water can get in the chances are it has lost it's oil which is a different type to standard engine oil. so the torque converter is useless any way. time to weighing up the cost of replacement of the torque converter and scrapping the car entirely.

generally when a torque converter has failed this is a fair indication the car has got so old it is near the end of it's life especially if it is over 10 years old.

SErvice the trans twice, flush the cooler. use Koolerkleen. blow out with compressed air from a dry system.

Then reevaluate.

Trapped water in there could mean a rebuild, and a rebuilt unit for the converter.

You would have to have a pretty large amount since it turns to cream or yogurt in the pan and stays there, hopefully.

it destroys the torque converter you'll need to replace it

other than sabotage a bad cooler in the radiator tank is the only it could get there. If you haven't noticed it and have been driving for a while your transmission will be destroyed.