If you mean on the 3 to 4 shift you have no governor pressure or intermittent it’s because the K2 drum has an internal leak or the K2 plastic piston in the valve body has a crack.

When doing oil pressure test always start with working pressure, all pressures derive from it. Next is modulating then governor.

The release for the governor is on the rear pump; look at page 50, fig. 42 of your link. They call it the axial retainer nut. Remove the 10mm nut and turn the screw CCW to release the governor, turn it CW when you install it, the slot in the screw should be in a horizontal position; locked.