Sonnax Vacuum Testing 4L60E Valve Body PT1 - Bad Valve Body!

Vacuum testing hydraulic circuitry is an integral part of the rebuild process and should be performed on valve bodies and pump stator supports during overhaul to minimize the chances of transmission failure shortly after rebuild. Here, I show how to use the Sonnax vacuum testing machine and their purpose-built test plate on a 4L60E. I walk through set up, calibration of the machine along with step by step vacuum testing of the valve trains to determine if we need to perform any additional valve body work before moving on. I discovered several areas of weakness or concern with this valve body while testing. The valve body being shown in this video is from the 4L60E featured in my '4L60E Autopsy - No Movement Mystery' video which you can find here: