Hy 696969, if you are saying that your plunger moves 3/4" before it starts to push the master cylinder piston, then that is too much clearance. If your saying that the pedal moves 3/4" before it starts to push the master cylinder piston, then your clearance is probably sufficient. There should be 1/16" to 1/8" clearance between the brake linkage plunger and the master cylinder piston when the brakes are released, don't forget to install a return spring on the brake pedal to make sure the linkage returns to its clearance position each time you release the brake pedal, hope that helps.