Hi,

I have read a lot of posts where cruise control has started to fail and been cured by replacing the stalk or brake switch. But I cannot find anything with my problem.

Its an intermittent fault, where with cruise control activated the brake pedal hardens. A second press of the brakes restores them to normal. Its a bit unnerving in normal driving, and if I found my self trying to brake hard in an emergency on the motorway I think I could end up in the back of something.

Can someone point me in the right direction?

I can't see how they would be connected. The CC is an electrical interaction with the ECU and Central Electronics. I think you may have another issue which for some reason manifests when you have the CC engaged.

I'd agree; the only connection between the VAG cruise and the brakes on these cars is a signal wire from the pedal switch which cancels the cruise when you apply the brakes.

A hard pedal makes me think that you're losing brake vacumn for some reason.

My firend had an issue on his golf, where cruise control would not engage. This was down to a faulty brake switch (it also falgged up his engine management light)

Also, I beleive there is a switch on the clutch somewhere, as once the clutch is engaged, that too cancells the cruise control..might be worth investigating.

** Sorry just read the rest of the post..doh!...checked your brake fluid leven recently?**

I'd agree; the only connection between the VAG cruise and the brakes on these cars is a signal wire from the pedal switch which cancels the cruise when you apply the brakes.

A hard pedal makes me think that you're losing brake vacumn for some reason.

^yep I'd agree with that.

what age is your car? i think some of the older ones were not 'drive by wire' and so there would be some mechanical element (possible vacuum driven?, or something is moving knocking a vacuum pipe?) to the cruise control, or is the cruise a none factory fit?

I have just had some of the vacuum pipes replaced as they were perishing so I'll give it a try over the weekend and see if thats what was causing the problem.

Thanks

Perished vacumn lines -> losing vacumn -> hard and heavy brake pedal.