Tdi brakes better wwhen cold

[fARQUARE]

Hello, my afn is ticking over fine apart from one small issue - the brakes feel more positive and have more initial bite when the engine is cold.
I'm suspecting the vacuum line to the servo might have perished and collapses when hot, has anyone else ever had similar issues?

The pedal certainly feels a bit more wooden when up to temp but when cold there is a really positive initial bite

[Oranoco]

Pad compound and or brake fluid that has absorbed too much moisture would be my first thoughts. Vacume to brake servo is generally a hard pipe that won't perish and if it did fail you'd lose the servo assistance and have a horredously heavy/wooden pedal all the time

[aragorn]

Maybe the vacuum pump itself is dying?

[fARQUARE]

But the vacuum pump controls the boost for the turbo and also the egr too, as i'm not throwing any codes and performance is great wouldn't I see other issues if the pump was on the way out?

I wouldn't rule out fluid but again I cant get my head around why the initial bite is better when cold. All disks and pads are less than 6 months oold so I can rule that out.

One issue I read about on tdi club was a broken rear box link pipe heating the brake lines under the rear bench. I fixed this pipe at the weekend as the liink pipe had slowly fallen apart, I guess i'll see if that repair has had any effect.