Vacuum testing the GM 4L80-E
From the TASC Force we reprint a series of in-depth test instructions for checking the serviceability of valve bodies.
Toyota U151E-U250E Vacuum testing
From the TASC Force we reprint a series of in-depth test instructions for checking the serviceability of valve bodies.
Vacuum Testing Ford 5R55W/S
From the TASC Force we reprint a series of in-depth test instructions for checking the serviceability of valve bodies.
Vacuum Testing ZF 6HP19/26/32 (Gen 1), Ford 6R60/6R80
From the TASC Force we reprint a series of in-depth test instructions for checking the serviceability of valve bodies.
Vacuum Testing GM 4L60-E
From the TASC Force we reprint a series of in-depth test instructions for checking the serviceability of valve bodies.
Vacuum Testing Toyota U140E/240E/241E
From the TASC Force we reprint a series of in-depth test instructions for checking the serviceability of valve bodies.
Diagnosing Valve Bodies with Vacuum Testing
Valve and bore wear occurs when valves repeatedly stroke in a pump or valve-body casting (figures 1 & 2). This wear will eventually increase clearance beyond what is necessary to maintain a proper hydraulic seal, making it impossible for the valve to function properly. Computer adaptive strategy will attempt to compensate for poor performance in some units, but failure ultimately results, codes are set and drivability complaints occur.
