excessive brake pedal travel doesnt come as a result of fade on the pads.
Maybe not always - but it can do. If you just get to the 'start' point of fading the pads (when they start gassing), then the pedal just feels wooden. But if the pad fade becomes much more intense, then the actual friction lining starts to brake down (the bonding agents basically 'melt') and becomes mushy - and this is when you can get a long pedal from pad fade. Then when they cool down, the pads then harden up again - though never fully, and the pedal travel will mostly normalise. A bit like if you leave a mars bar on your dash in the sun - it goes all squidy and 'orrible, but put it in the fridge and it firms up again, but isn't the same! When you remove pads that have been faded to extremes, the friction lining often just crumbles away from the back plate.
But yes, I also agree that boiling fluid will also cause the pedal to sink to the floor. But there is a subtle difference - with just pad fade, the pedal gets progressively longer and longer, whilst boiling fluid will send the pedal all the way to the floor in just one go.
I have still managed to get all my brake pads to fade at some point n track, but only with Oem fluid did i get the excessive travel.
Then you must be seriously spanking your brakes.
Like I said though, OEM fluid isn't ideal for such use, and proper motorsport rated fluids should be used in such extreme conditions.
Come to think of it when my pedal got like that i went for a really long cruise to cool it all down, before trying it again on track. it happened again and i went back home. (the joys of living 92 mile from the ring ) I changed the fluid and pads that week and they were fine the next time i went.
But what were the pads like? Were they all 'crazed' and crumbly?
I reckon both the fluid AND the pads were at fault - and I wonder if you just changed pads alone, weather the pedal would have restored (after correctly bedding them in). (I'm not advocating not to have changed the fluid though!).
Apologies for the mis-interpretation of your post,
No worries mate - I'm sure we are all prone to misquoting others from time to time, me included.
and whilst the top end VAg vehicles might use the same fluid, there are many other variables that would make it work better in them than it would mine, for instance massively larger discs that deal with the heat in a much more efficient way, cooling, ducting etc etc.
And you have hit the nail on the head. Can't remember if you have a vRS or a GTI - if you do have a GTI, have you fitted the 'open' fog lamp grilles? Because these actually make brake cooling worse! Because you seem a bit of a hardcore track addict, have you thought about possibly ducting your brakes?