Hard brake pedal

[Timbo69]

Hi,

I've had a 2.0 TDi DSG for about 3 months now. It has keyless entry so the brake pedal needs to be depressed to start the engine and a couple of times now I have got in the car (once in a morning to go to work, another time in the afternoon to return from work) and the brake pedal has been rock hard. So hard that even when I'm pressing it the dash is telling me to press the brake pedal to start. A little pumping results in the engine starting and once started the servo kicks in and the pedal returns to normal.

Is this a fault or a 'feature'?

Many thanks.

[Paddy_R]

I think all Sciroccos need the brake/clutch pressed to start the engine. I know mine does and it'd not keyless. As for the pedal issue you don't happen to live on a hill so sit with your foot on the brake when you're parking do you?

Edit: on my old Clio RS200 you had to press either the brake or the clutch. Renault obviously weren't as fussy ad VW.

[Cuprabob]

Only DSG models that need the brake pressed. On manuals you need to depress the clutch.

[Timbo69]

No it's a flat driveway

[Phil]

I don't have to on mine, but could be as its an 09

[froudeg]

Sounds like you have a vacuum leak (not a boost leak but a leak in the vacuum lines from the vacuum pump, vacuum pressure vessel or the brake booster vacuum line)

The brake pedal relies on vacuum pressure for the brake booster to work. Vacuum pressure is only built up when the engine is running, but should be retained when you switch off.
If there is a slow leak then when you come to start the car the next day the brake pedal will be rock hard as the brake booster will have no vacuum pressure.

You need to check all the rubber hosing for cracks, and also check the hard plastic pipe to the brake booster.

[M7R]

As above, you have a vac leak somewhere as the vac shouldn't leak off that quick.

[Timbo69]

Well I took it into Inchcape Stockport to have the hard pedal and also some annoying rattling in the foot well looked at. They said the pedal was normal, as long as it's not hard when driving then it should not be a problem. There was also a list as long as your arm of things that weren't screwed in properly causing the rattles....which doesn't inspire me with much confidence.

[xjay1337]

The vacuum built up will go after about an hour.

[blower]

In my old Golf Mk5 (TDI 2.0) and my current Golf Mk6 (1.4 TSI 160) - the brake pedal is never hard, even after sitting overnight.

I did have an issue a few weeks ago after doing some work on the car and disconnecting many vacuum lines when removing the intake manifold.
I had a hard brake pedal In the morning, I monitored the vacuum pressure with VCDS and it was slowly falling off until it was gone after a couple of hours.
I refitted various vacuum lines, and in particular paid attention to a rubber grommet on the brake booster vacuum line that I previously removed.
Since then i'm back to a normal brake pedal in the morning and monitoring the vacuum pressure it barely falls off, even after sitting for 12 hours.

Long and short of it is you probably have a very slight leak in a vacuum line, as above its not a problem as the leak is so slight that it's easily overcome by the vacuum built up when running. But its not normal or a feature.