Under the bonnet against the bulkhead you will find what can best be described as a black rubber sock. This can fill up with silt and leaves. Give it several good sqeezes so that the muck comes out of the bottom, or pull it off and wash it out. If left blocked water runs in through the heater ducts, and you will have to strip out the carpets to get them dry again.
Archie Harris, January 2009
