underdog

Just started a restoration on my 78 280 that was been up on blocks for several years. Need to rebuild the clutch hydraulics which is in progress but tried to manually cycle the clutch fork while the slaved cylinder is off to see if the throwout bearing is frozen. Anybody have any idea how much force on the end of the fork to move the throwout bearing. I tied probably around 30 pounds using a long pole from under the front of the car with no luck. Didn't want to bend anything internal. Thanks in advance