braking in the cold

[tonydunning]

VW Passat 02 reg, tdi. Braking problems when weather is cold/frosty. Feels like servo not working properly, but works fine when the weather is warmer. What could it be? Servo pump has been replaced but this didn't fix the problem.

Any suggestions?

[Col]

Your car may have suffered or is still suffering from the infamous blocked plenum drains problem. Do a search here for lots of info.

In short, the servo may have rusted around its seams and drawn water in. If that water has frozen, the servo will also be effectively frozen.

Just my hunch.