Brake power regulator

[84CoupeGT]

Afternoon all

Quick question, does this look about the right amount of movement in the brake power regulator? The Haynes manual says the lever should move when the brake pedal is depressed and released with the weight of the car on the ground, but it doesn't say by how much. In the video below I was standing on the brake pretty hard, and it was moving, but not very much. I'm guessing the internals don't need much movement to allow more/less brake fluid through and therefore regulate the pressure, but thought it would be good to see if it looks normal with those who have more experience!

https://youtu.be/by3f46ztPqc

I appreciate it can't be fully tested without high pressure gauges.

Cheers