Hi there guys. Finished a track day, and at the end of the night my clutch pedal went straight to the floor. Still engaged, but a lot of "air". Noticed my clutch reservoir was empty. I bled it, and refilled to find I still got slack at the top.

Took a look at the master cylinder to find it was leaking. Figured that was the issue with the slack. Replaced the master cylinder but I still have the slack. I adjusted the nut connecring the master cylinder to the pedal but it didnt fix it. The slack isn't from the pedal assembly it's from inside the systems BUT there was not air in my lines. I bled it extensively and no bubbles or air were appearing.

Has this happened to anyone else? How did you fix it?

 

Try unbolting the slave cylinder and manually orienting the bleeder valve in a way to get the air out. Most likely you got some air stuck between the bleeder valve and the end of the slave cylinder and it can't get out.

 

Air guaranteed.

Unbolt slave and pump the plunger by hand. The air will go out the top. You don't even need to open the bleeder.

 

I'll assume you checked your clutch fluid before your track event and it was full? Your leak was so bad it emptied the reservoir at a single event?

 

Ill be honest and, no, I didn't check. Not necessarily due to negligence, I'm simply sort of new to maintaining a car myself and didnt check it before the event. However, I'm still learning the car and actually didnt drive it very hard. Mostly just getting a feel for the car. Not necessarily justifying my mistake, just giving a bit of context to the emptiness of the reservoir. It was a 2 hour drive home, and the clutch was 100% normal (feeling) all the way home. It wasn't until hours later when I got back in my car to drive home did I notice the clutch having a lot of air.

 

Well, I won't lecture you on proper track maintenance then.

Good luck getting this sorted.

 

You said you are new to car maint but also said you were sure you bled it thoroughly. Air in systems (clutch, brakes, coolant) can be tricky even for experienced mechanics. How can you be sure your bleeding efforts were thorough?

 

I'm NOT sure. I didn't bench bleed it which could be the issue. A friend of mine has a vacuum bleeder and I think I'll give that a shot. Should remove all the air. I'll keep you all posted on how it goes.

 

This will take 5 minutes, works like a charm.

 

Not to sound naive, but is there perhaps a DIY on doing this specifically? I see guides on how to swap the slave, but not simply "unbolt" it. Or pumping the plunger by hand. Apologies for being difficult.