Clutch hydraulic repair. Rule of Thumb?

What is your question?

Hi, my first post here. '91 S-10, 2.8L 5 Speed. Can't keep fluid in the clutch hydraulic system. From reading other posts, it's probably either the resivor, hose, master or slave cylinder. Question: Is it necessary to replace X when you replace Y? Thanks!

How long has your 1991 Chevrolet S10 had this problem?

Couple of months