I was driving my car this past weekend and it was driving fine as usual. About 45 mins later I notice that it was getting harder to shift into gear and as soon as I stopped at the next stop sign it wouldn't go into any gears. I had to force it onto 1st gear to drive to the side of the road. I turned the car off and only then I was able to shift into any gear. It wouldn't go into gear when the car was on. When the car is off I am able to shift into any gear. I checked the master cylinder and it was a little low so I filled it up. I kept pumping the clutch to see if the fluid would drop but didn't. I then tried to drive the car again and the faster the car went the easier it was to shift gears. I was able to drive the car home but I was still able to feel that it was a little hard to shift into gears. Any ideas on what it can be? Where should I start?

 

Your problem sounds like a slave cylinder issue. Get the trans out and inspect the clutch, pilot bearing and slave cylinder. While you have it out I would replace the pilot bearing just for good measure if it hasn't been replaced recently.

 

How can you tell if the slave cylinder is bad once it is out?