The problem with using a torque wrench on the rear servo is cushion spring in the center of the piston...if you tighten the adjuster stud enough, the cushion spring compresses when there is no play in the linkage so when the adjuster is backed off part of the travel is used in decompressing the spring.

It's better to turn the adjuster stud in until there is no perceptible slop when pulling down on the lever...use this as the zero point to back off the desired number of turns.