Transmission Fluid Flush
A maintenance service that uses a specialized machine to replace all old transmission fluid with fresh fluid.
A transmission fluid flush is a service that removes nearly 100% of the old fluid and contaminants from the transmission, torque converter, and cooler lines, replacing it with fresh fluid. This is typically done using a specialized flushing machine connected to the transmission's cooler lines.
Unlike a simple pan drop and drain—which only replaces about 30% to 50% of the fluid because the rest remains trapped in the torque converter—a flush ensures a complete fluid exchange. It cleans out accumulated varnish, sludge, and micro-particles of clutch material that can clog solenoids and valves.
There is some debate about flushing high-mileage transmissions that have never been serviced, as the flush could dislodge debris that might clog internal passages. However, on well-maintained vehicles, a regular transmission fluid flush is highly effective at preventing shifting issues and extending transmission life.