Brake pedal different before engine start and hissing noise

[grumpazoid]

Hi All.

My first post on the forum .

I have a B7 early 2014 Passat 2.0TDI that has been under warrantyup until a recently.

The last couple of times I have got in the car, I've noticed that the before the engine is started the brake pedal is stiff. Never noticed this before.
Also when pressing the brake pedal (with engine off or running) there is a hissing noise.

I have read up about the brake booster / servo and basic tests seem ok :
1. press pedal a few times. Apply pressure to pedal and start engine. Pedal then goes down as vacuum is applied.
2. Leave engine off for two minutes. Try pedal. There is some pedal assistance so vacuum being held for 2 minutes.

I can't help thinking there may be a slight leak somewhere as if left longer the pedal goes solid and I have the noise.

One other thing that I hope is not related - I recently changed oil and filter myself and reset both service counters. (last time the local VW garage managed to mess this up and damaged 2 driveways in the process)

Any help appreciated.

Grump

[UMEL]

I have never done this before so gave it a try.

Pressed the brake pedal and it went down about 30mm and hissed. Pumped it 3 more times, each time travelling slightly less but hissing then it went solid.

Keep pressing start engine and the pedal goes down about half way.

Stop engine and wait 2 minutes...pedal goes down about 10mm to take up slack but then rock hard.

I would say mine is the same as yours.

[Crasher]

Servo failure on these is not unknown, it would need a quick vacuum test.

[grumpazoid]

I would say mine is the same as yours.

That is good to know. I am beginning to think it is quite normal. the hissing sound I can hear seems to be coming from the concertina looking housing directly behind the pedal. I am guessing just air escaping as it gets compressed when pressing the pedal quickly.
brake.jpg