Clutch fluid dissappears

[Effieman]

My 98 Ranger keeps losing fluid from the clutch reservoir. Can't see any leaks anywhere. Bell housing is dry. Can't see anything around firewall. Clutch stops working, then I refill the reservoir. Refilled yesterday, but still hardly any pedal. Been doing this for several years, but this is the first time it didn't fix upon refilling.
Any ideas?

 

[franklin2]

Look inside under the dash. It might be leaking out of the master cylinder and running down behind the insulation pad.