I have a 2003 Mazda 6 with the 4 Cylinder, Manual Transmission. It is my wife's daily driver. For the past few months the car has been getting harder to put in gear (especially reverse). It has finally gotten to a point where it does not want to go into gear at all. The pedal goes almost all the way to the floor with no resistance. The slave cylinder is moving once the pedal hits the floor. Then the pedal does not return. I do know a little bit about cars, so I attempted to bleed the slave cylinder. The first time I loosened the bleeder alot of air came out. Bled it a couple more times till we got all fluid. Wife said she had a good pedal, so she drove it up the road. Did fine for a while, but was doing the same thing when she got back home. Tried bleeding it again and got alot of small air bubble out of it. It still has the same problem. How often do the slave cylinders wear out in these cars. It has roughly 110,000 on it. Also, where would I find the master cylinder at? It looks like the brakes and clutch use the same master cylinder. Not really wanting to take it to a dealer to see what is wrong. Just wondering if anyone here had any ideas. Thanks in advance.