Getting the old fluid out of a torque converter is typically not done by directly draining the converter itself, as many torque converters do not have a drain plug. Instead, the fluid is replaced through a process that involves the entire transmission system.
Based on the provided reference, the most practical and effective way to address the fluid within the torque converter as part of a fluid change is through a repeated transmission pan drain and fill procedure.
The Pan Drain and Fill Method
This method leverages the fact that the torque converter is part of the transmission's fluid circulation system. When you drain the transmission fluid pan, you only remove a portion of the total fluid in the system. A significant amount of fluid remains within the torque converter, valve body, cooler lines, and cooler.
Here's how the method described in the reference works:
- Drain the Pan: The easiest and best initial step is to drain the fluid from the transmission pan. This removes the most easily accessible volume of fluid.
- Replace Volume: Add the equivalent volume of new transmission fluid back into the transmission through the fill tube.
- Drive Briefly: Drive the vehicle for a short distance. This allows the transmission fluid pump to circulate the new fluid throughout the system, mixing it with the old fluid remaining in components like the torque converter.
- Repeat if Necessary: If the old fluid shows signs of overheating (e.g., dark color, burnt smell), you will need to repeat steps 1-3 two or three more times. Each subsequent drain removes more of the old, mixed fluid, and each fill adds more new fluid. Over several cycles, this process effectively flushes out the old fluid from the entire system, including the torque converter.
Why This Method Works
- Gradual Replacement: This method gradually replaces the old fluid with new fluid throughout the entire transmission system.
- Simplicity: It avoids the need for special tools or procedures to directly access the torque converter.
- Effectiveness for Flushing: Repeating the process is particularly effective for 'flushing' out degraded or overheated fluid from components like the converter that don't drain directly.
While this method doesn't directly drain the torque converter in one go, it is the recommended approach in the reference for replacing the fluid that resides within it as part of a standard fluid change or flushing process.
