Sticking/Soft Clutch

I drive a 98 subaru legacy outback that has 140K miles, and after many disappointing failures the car now has a clutch that has gone soft all of a sudden. The clutch began sticking in the down position yesterday when I drove it for about an hour’s time while out doing errands around town.



A little history: The clutch was replaced by my mechanic about 4 months ago. Prior to the clutch change out, my mechanic remarked that he thought my car’s clutch required a super strong left leg to depress and further commented that he was surprised that both my legs look the same size.



Anyhow, I am taking it in next week, and I am wondering if I should accept the fact that I will need to pay parts and labor for a new master and slave cylinder, or if it is equally likely that the problem can be put to bed simply by rebleeding the cylinders and making sure no air is present.



Or, is it reasonable to think that if the clutch is changed out, it is probably a good idea to replace the slave and master cylinders at the same time? How much does a job like this cost?



My faith in my mechanic is a little shaken anyway, because at the same time they changed out the clutch a few months back, they also changed out an alternator. Three months after that change out, the alternator died, and they redid the job for free, and cited the alternator as the culprit–according to them they installed a dud and the bad part was covered under warranty. I can’t help wondering if it wasn’t that the replacement alternator was bad, but that the installation job might have been bad.



I mainly would like to know if the soft clutch, in light of the recent clutch change out, points to a need for a new master/slave cylinder assembly, or if the clutch return system might have been personally adjusted by the mechanic to ease the burden of my left leg. Could an adjustment like this cause a cylinder failure? Would I know if the cylinders were leaking? What are the possible causes of the soft clutch in light of the recent clutch change out?

Thanks in advance.