What percentage of transmission fluid is typically removed by draining the pan?

When draining the transmission pan, it is common for only a portion of the transmission fluid to be removed from the system. Typically, the amount of fluid removed during a pan drain is around 50% to 70%. This is primarily because the fluid that resides in the torque converter and in various passages and cooler lines remains in the system.

When a technician drains the pan, they can access a significant portion of the fluid that collects in the pan due to sediment and particulates settling over time, but the total volume removed does not encompass the entirety of the fluid present in the transmission. Therefore, 50% to 70% accurately represents the percentage of transmission fluid that can be removed through this method, reflecting the limitations of a pan drain and the presence of fluid that is not easily expelled from the system.