Caliper on front brakes rattle on 2008 A6 (C6) Avant S-line

[Alfie6]

Hi - I have recent acquired a 2008 A6 (C6)avant sline and I am experiencing rattle from the front brakes driving over rough road surfaces. I note the car has recently had new discs and pads and only 10% worn. I have renewed the caliper springs on both sides and this has largely improved the problem but annoyingly there still some rattle from both sides. Being a sline with harder suspension is this a common problem on these cars on our bad roads. Further my local  garage has inspected the suspension and can only find that anti-roll bushes may required to be replaced in the distance future, and could only be an advisory on the MOT, but offer no more advice. Anybody had the same problem and solved it?

[Alfie6]

Hi, its Alfie 6 again, and I now intend to inspect the front calipers. Before I do so I would be pleased if anybody could direct me to an explosive diagram of the caliper unit.  Having worked on previous calipers, there appears to be a lack of support for the pads, having only the outside spring to stop rattle of the outer, and the cone one which goes into the piston?  Please note that my car is an 2008, which is different from the later models, which has an over lapping external spring. Any help would be much appreciated.

[cliffcoggin]

Stripping the calipers is a good idea, but I can't help with personal experience or diagrams.

[spartacus 68]

What make are the pads and rotor? Is there excessive corrosion on the brake carrier so it’s lost shape.

Have a look at diagrams here and cross-check on your engine code. https://www.lllparts.co.uk/catalogs/audi/RDW/A6/448/6

For brake sliders, pad shoulders and piston face use a little ceramic brake grease. The brake carrier bolts should be okay to undo if you’ve new hardware. These bolts tend to seize if left untouched for periods of time.

Edited 14 hours ago by spartacus 68

[Alfie6]

Thank you for your reply.

I have the invoice for brake pads ( dated 18//07/23) and they are Borg and Beck BBP1766 from Motor Parts Direct - I have checked their web site and they are correct. I note new discs were also fitted at the same time supplied by them BBD4509, which are correct. 

With regard to carrier wear the car has done 12500miles, and don't believe the car has been driven hard, since I know the previous owner, who has owned the car from new.

Thank you for the very helpful diagrams and note the only spring on the caliper shown is on the outer which I have replaced. I find this unusual as other calipers I have worked on have springs in the base of the carrier and hold the pads tight in the holder.

I have ordered some ceramic brake grease and will carry your recommendations and will let you know.

Thank you again.