So i've been having an issue with my clutch pedal. It's mostly fine. But if it gets hot, the clutch pedal gets firm and kind of sticks. Like i can raise my foot off of it and it's slowly rise by itself like it's a bit stuck. This only happens when it's hot, like after i drive for like 15 minutes at 60mph with no shifting, once i get into town the clutch is sticky. If it's a cool day, the problem doesn't arise. Today was a cool morning and it didn't happen. Anyways, any ideas at what could cause that and how to resolve it? Thanks!