Dreaded hard brake pedal on B6 1.9tdi 130

[jp33]

Hi all, can anyone help with this?.My A4 1.9tdi 130 developed the intermittent hard break pedal, especially on colder mornings ,to start with it was very occasional and I kinda lived with it for a bit, I then bought a C6 3.0 tdi avant and sort of abandoned the trusty A4 for a few weeks,The excitement of new car etc!!.

Anyway I knew the A4 was due an MOT so booked it in and drove to the testing station, during the drive I noticed that the break pedal would go hard alot more than it ever used to.Anyway surprise surprise it failed on 'no servo assist from brakes'.The mechanic said he checked there was vacuum from the pump and that I needed a new servo, I would normally do my own work but because of various commitments coupled with dark evenings I got a new servo and tasked the garage with fitting it.

So, this they did and re-MOTd the car and issued a pass ticket. I picked the car up and paid the bill (which hurt) and proceeded to drive home, at first all seemed fine then whilst moving inn slow traffic at low revs the pedal was still going hard and braking was non existant. Of course I rang the garage up immediately slightly ****** off to have the same problem despite being a few hundred quid out of pocket!! They were no help and the guy who diagnosed the problem was now on holiday and not back for a week!!, this is why I normally do my own work.

So if he said he has checked vacuum from the pump and now it has a new servo, is the problem with the pipes as I cant see what else it could be, they did say they had to replace a plastic clip that joined pedal to servo??, I suspect heavily that they probably broke it upon removal, anyway the guy is back from holiday tomorrow and I will take it back to see him and find out why after spending £550 does my car still have same problem. I should point out that there were also wiper blades, a bulb,handbrake cable ,rocker cover gasket,and a fuel filter also fitted, both the rocker and the fuel filter were leaking and were on the mot failure sheet.

If anyone has any helpful advice on this subject I would be very grateful to hear it, the forum has been very helpful with my c6 queries so I'm sure it will not let me down. Thanks for taking time to read about my woes. JP

[Crasher]

I would suspect it is a simple leak in the system so you may have had two faults. Presumably you supplied them a brand new servo? I would take off the vacuum pipe to the system and apply a vacuum to see if you can pull air and do this to the main servo feed pipe too but this requires quite a capable vacuum pump. It would also be nice to actually measure the vacuum developed by the pump but you need a gauge for this.

[jp33]

The servo was a brand new part supplied to them. Do the pipes have a history of collapsing or kinking?. I decided not to revist the garage today but will instead check the problem myself this weekend. According to Audi there are two pipes but Poole Audi would rather have a part number off the old ones if visable.

I will definitely take your advice and check out the pump, I think a guy at work has a gauge I could borrow also, will try and find out what it should read .Will keep you posted on what I find. Cheers mate.jp

[Doctle Odd]

How did it pass MOT 2nd time with the same problem?

[green A8]

How did it pass MOT 2nd time with the same problem?

I was wondering exactly the same.

[jp33]

This did puzzle me too,the mechanic acted a bit dumb and said it was ok on the break test, this makes me wonder if retest was even done, beacuse at low revs after the initial braking the peddle then becomes hard again,another reason not to take the car back there.jp