The pedal feels different, less precise perhaps. I forgot/neglected to bleed the fluid it when it was off the road for 13 months. I bleed the brakes often, hopefully the law of entropy means that I am still getting any moisture out, I assume moisture moves into the common brake fluid. I never bleed the clutch slave or master ever. About 124K miles, original owner. All related parts from 1994.

You have an external slave, and the piston may be sticking or the rubber seal is falling apart. It requires a look see, not fun this time of year.

Bleeding the brake MC and slave should be done, but it is a PITA. Especially when there is only one person. While under the car, take a good look at the adjustment nut. It tends to rust, I have been known to coat it in axle grease - the really heavy stuff. Too bad it cannot be plasti-dipped.
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Keeping it running is better than buying new