This should be easy for you to fix. I recently had a similar problem in which the clutch pedal resistance was NONE.
This is what I would recommend:
Check for obvious leaks from the master cylinder, clutch line and the slave. No obvious leaks? Make sure your system is bled. Easiest way is to pull the slave, remove the master cylinder cap and pump the slave piston until you cannot see air coming from the slave. Also Check:
1. Pull the slave off and have somebody pump the clutch pedal to make sure that is not the problem. If the piston moves in and out you might be in good shape with that. So reinstall it and move to step two.
2. Check to make sure the master cylinder is not leaking (air or fluid). This was the problem with mine. It had pressure, but the seals were not holding enough and air pressure was being released. After about the fourth pump of the clutch pedal, I could hear air releasing (under the dash near the linkage to the clutch pedal).
Usually it is either your slave or master. Clutches last a while and are pretty tough. If you do end up replacing the master, you may as well replace the slave if the age is similar.
Hope this helps.