This is part six of a seven part series on how basic automatic transmissions operate. In this video I explain the purpose of a valve body and the common valves found in a valve body. I cover how a common switch (shift) valve operates in conjunction with an electronic solenoid. I also cover how constant and variable pressure regulator valves operate. This video is intended to teach a student or a technician that's new to automatic transmissions the basics of automatic transmission valve bodies. For more detailed explanations of valve bodies, refer to the videos I have on specific transmissions.