Hi. I'm new to posting on the forum but have viewed many topics with interest in the past. We have a very reliable (until now) '02 Octavia diesel with an odd clutch hydraulics fault. 3 months ago clutch went soft. Checked for leaks, found none, assumed slave cylinder and changed it. OK until a couple of weeks ago. Same issue. Bled system and all fine again. Now lasting about 4 days then needs a bleed. Have not removed new slave as yet and am sure there are no leaks at master, along pipes in engine bay and no fluid at pedal - all is dry. Fluid level does not change significantly so level has not fallen below clutch pipe outlet. Has anybody experienced this before? Could this be a fault that for some reason does not produce a visible fluid trace?

Sounds like the master cylinder is drawing in air then.

My clutch pipe was leaking where it plugs into slave cylinder, wasnt loosing much fluid but kept loosing pedal if sat in traffic

It's worth noting the seals 'should' be replaced when something is disconnected.

You need to follow the correct procedure for bleeding the clutch. see http://www.briskoda.net/forums/topic/258616-biting-point-changes-after-clutch-change/#entry3042970

I managed to do mine my hand pumping pedal after i changed clutch pipe as some fecker had emptied the pressure bleeder of brake fluid and just left it,

The clutch pipe isn't that long and is quiet direct so one you get a pedal and then get the car warm i would think all air would rise out of system over time anyway, another way is to get somebody else to hold pedal down and you crack bleed nipped off and keep repeating that works well as it bleeds the slave cylinder better,

I've come across odd cars that are a complete pain to bleed up and even stuggle to do it properly with a pressure bleeder but vrs has always been easy and its same setup as diesels

...i would think all air would rise out of system over time anyway...

The air gathers in the clutch master cylinder. If you have air in there, you have to power bleed AND pump the pedal, as there is no bleed nipple on the clutch master cylinder.