Flush vs Drain-and-Fill: The Difference
- Drain-and-fill ($89): Drops the pan, replaces the filter, and refills — exchanges about 40–50% of total fluid volume. The torque converter retains old fluid.
- Machine flush ($149–$199): Connects to the cooler line circuit and runs the pump to push old fluid out while simultaneously adding new fluid — exchanges 90–95% of total volume including the torque converter.
- When a flush makes sense: Vehicles with fluid that's degraded but still serviceable (not burnt/black), or when you want the most complete fluid refresh
- When drain-and-fill is better: Severely degraded or burnt fluid — a flush on badly compromised fluid can dislodge debris and cause shifting problems
