Brake pedal return / Servo

[jono_01]

Hi All,

This forum and others has given me some information but hoping someone can give me more information.

Pressing brake pedal; seemingly operates as normal but maybe 3/4 of its full distance is stiffens up (ie. more than you would expect). This is only really noticeable when you're driving at high speed and need to stop or slow down in a short distance. Main issue seems to be the slow return of the brake pedal. It does return fully, but takes a few seconds to do so. Brake light remains on and brakes do seem to be 'dragging'. Will then release.

 

Had the car in the garage for something different. They had a quick look and said discs, pads and calipers seem ok but will get it up in the air and check properly. I've been warned that it (hopefully) could be something simple such as split hose or in worst case scenario could be knackered servo. 

I trust the guys (used them for years) but they are not Audi specialists. They reckon that if it was a replacement servo that it might be an engine out job, which is probably not going to be cheap on a 3.2 quattro.

I'll be getting it back in at the end of the month for more investigation, tyres, service and all being well an MOT.

I've had a look but can't see any obvious hose damage around the servo or hear any hissing.

Has anyone had this issue before on this model or another? Would it be an engine out job or can it be repaired or replaced in situ?

Thanks in advance

[Audi Owners Club.]

Hi Jonathan...welcome to the Forum

My first thoughts are put it in for an MOT first which will incorporate looking for brake fluid leaks, servo operation, hoses and pipes being inspected, and also a brake roller test to measure the efficiency of the system. If it needs the MOT test then it could go in early and save yourself the inspection time in the garage.

Secondly, sounds like a servo fault to me, but I wouldn't rule out vacuum leak(s), mechanical linkages, etc.

Keep us updated on what you find.

Cheers  Trevor

[rbdazza]

as above, sounds servo related to me. Quick Fit (sorry to swear,...) offer a part MOT mid term, which is around 25 quid. they basically MOT the car without logging it and give you the results. 

[jono_01]

Hi Trevor, thanks for the speedy reply. I'll be getting it booked in within the next 3 weeks and will ask that the MOT is done first with the tyres it'll probably need.

I'll certainly post the outcome.

Would you have any idea what kind of labour would be involved if it is a servo replacement? I'm just trying to work on a 'worst case scenario' basis at the moment.

 

Cheers

[jono_01]

The Kwik fit option doesn't sound like too bad an idea actually. Thanks

[jono_01]

I have had the brake servo replaced and this has resolved the issue.

I took the car to a local VW group specialist instead of my normal garage a. because they are round the corner from work and b. hopefully they've come across this issue before.

I didn't tell them my suspicions but they were non committal initially and wanted to rule out anything simple and straightforward. I got it booked in for it's MOT and (unsurprisingly) it failed on this "Mechanical brake component has restricted free movement (3.5.1k)"

They spend additional (uncharged) time investigating and their diagnosis was that it was the servo. Their repair manual suggested a repair time of 2.5hrs but that was for a LHD vehicle. They did warn me that it would be time consuming and that the engine would likely be unmounted... Their best guess at that stage was about 8-9 hours labour. It came in at 7.5 hours. All in all, the repair come in at just under £800 however that is exactly 50% of what Audi quoted me at £1600.

Don't get me wrong, I could have went to a back street garage and paid 35/40 an hour or whatever the going rate it but I thought I'd go with the specialist.

I'm over the moon that the brakes are fixed (although admittedly, they feel different - it could be that I had got used to the courtesy car's brakes) and there is definitely a change in moving off in first gear (S tronic). Previously, if you had been stationary in P for a time and changed to D then released the brakes (not instantaneously I note) there was like a kind of hesitation and minuscule dip in the idle. Same happened if you were in D with foot on brake and released/accelerated.  I didn't think it was gearbox related. That also seems to have resolved/improved so may have been something to do with the vacuum perhaps?

It may all be the placebo effect right now but thus far it seems to have been sorted.

Any comments whether this was too much to pay / about right? Part was £301.

Also, would this hesitation on moving off issue really be as a result of a bad servo?

 

Thanks