wall mounted cistern, metal plate on top of rubber (donut)seal with 2 wingnuts onto pan no seal between this and cistern. Leaks from this area when flushed
You can usually (sometimes) fix a leak here just by doing up the wing nuts and compressing the doughnut washer a little more.
Sometimes the large pipe coming from the cistern projects a little too far into the hole at the back of the pan - this will make the cistern tip slightly on assembly and make it very difficult to make a leak proof joint.
Check for this by squinting sideways along the joint line - you should see a thin parallel line of doughnut washer
if it is not parallel then you may need to remove 3 or 4mm from the end of the delivery pipe.
