I bought a digital scale to find out. Below are two videos. One for the max amount Boomer can push and the other for the max pull.
As you can see Boomer can push more than he can pull. So I will weigh 6 bottles of water.
First I will weigh one bottle. (516 grams)
I then weighed Boomer. (1.749 kilograms)
AX-12 servos with AX-18Fs? AX-18F have 18 kgf cm holding torque vs. 15 for the AX-12+.