CITROEN announced a problem with the C6 affecting a total of 426 vehicles.
Possible oil seepage in the brake assistance circuit that could damage the brake amplifier membrane and reduce braking assistance. Vehicles built from 7/21/2005 to 12/1/2006 are at risk.
The following remedial action is necessary to address this problem. Recall the vehicles that are likely to be affected to replace the vacuum circuit valve and pipe which link the vacuum pump to the brake amplifier.
If you think that your vehicle may be affected by this recall you should
find your nearest CITROEN dealer
who will be able to confirm whether or not your car is safe and arrange its free repair if necessary.
Source: UK Government's Vehicle and Operator Services Agency (VOSA).