[DeTomaso] clutch release lever and adjustment question

[boyd casey]

How hard should it be to pull the clutch release lever (with vise grips). I
have been having trouble with my clutch disengaging and I am in the process
of replacing the slave cylinder and master cylinder. Once I had my slave
cylinder piston disconnected from the clutch release lever I tried moving
the lever back with a vise grip and it was extremely difficult. How hard
should it be and how far should I be able to move it and how much movement
(typically) is there in taking up the free play 1/16th" or 1/2 " ??. What is
the correct brake fluid to use #3 or # 4?
Thanks, Boyd