5K Clutch Questions

[Steve Sherman]

The clutch pedal in my 87 5KTQW (~135Kmiles) is a bit stiff, with a
on/off sort of action, and not as smooth as other 5K's of this vintage
I've driven.  The pedal itself is not rough (although it is stiff) but
the clutch seems to engage all at one spot. It's been this way for about
40K miles or more. About 1 year ago I replaced the master cyl as the old
one was starting the pedal won't come up thing, but that didn't really
change anything.

I asked my shop to check it out, and they said it was just the clutch &
pressure plate and to start saving pennies for a new clutch.

Fine, but recently in the cold weather, I have noticed that the clutch
pedal action is improved.  Not to as good as other 5K's, but
substancially better. (And it was always worse in hot temps anyhow).

My question for those that know, is could it be that my slave clutch cyl
is marginal, and cold weather makes it better?  It seems like a possible
explanation.  Or is this just wishful thinking in the hopes ov avoiding
a new clutch?

TIA