AED Overflow pipe

[SYC378L]

Morning Gents,

A few weeks ago my car began haemmorhaging fuel from the AED overflow when warm. The car seemed to be running ok. I removed the bi-metallic strip from the top of the AED as well as other bits and pieces and have them a good clean before reassembly. This seemed to work, a trip to Leicester and back last weekend saw the car running fine. Last night however, the car started to drop fuel out of the overflow again, although not to the same severity. Only seems to happen just after coming to a halt and comes out at a higher rate when reversing, which is strange! Any ideas what is causing it? Blocked fuel line and/or filter?

Regards,

Will