We have a 98.5 24v 5 spd, 4x4 1 ton, the clutch pedal has become too stiff for my wife to push, its her truck now, i used to drive it, and its always been stiff, but its gotten worse, we have another just like it we bought the same day and its never been stiff, and my 94 isnt stiff, or my '03, what's the deal? what can i adjust or replace, slave, master, etc., any help would be great, thanks...