Recently I noticed (in my 2000 Lude) I was loosing pressure in my clutch pedal. I ended up having to replace my master cylinder and slave unit. The clutch itself is a stage 2 with about 30K or a little less on it. Now when the car is left idiling for a bit and I go to drive there is a huge increase in the pressure in the pedal. I've pretty much narrowed it down to when its left idiling as the main time it happens. When I drive the car like this it is like the clutch is slipping. If I let some of the pressure out via the bleeder valve its fine. This doesn't make any sense to me because the whole system is enclosed and pressure isn't introduced in any way for it to operate. The only possible cause i've thought of.. somehow the lines getting heated up and causing a build up of pressure but all the lines are back where they were originally..Someone please help because i'm lost...

 

Have you checked your lines for knotting/bends? That can cause a increase in pressure through the master/slave cylinders. Also it could be your pressure plate.

 

yeah the lines are fine...How would its be the pressure plate without it doing it all the time?

 

Try re-bleeding your clutch system if the lines are fine. My friend had a capri with a extremely stiff clutch pedal and he fixed it by replacing his clutch lines.

 

I've bled them 3 times so far with no success...everything was great until the master cylinder and slave unit were replaced