Fuel smell when braking

[hullguy1974]

Hi I have a peugeot 307 and everytime i break sharp in traffic i get a very strong petrol smell in the cabin. I have checked the fuel sender unit in the tank and the seal is in good condition and no signs of leakage. The car is fine until i brake in traffic ive been looking on forums and no seems to know what the cause is. I have been told its possibly the carbon cannister under the front off side wing. I have searched over the car and can find no signs of fuel leakage now its got to summer the smell with the heat is driving me insane. Has anyone found the answer to this problem.

Thanks