Discovered water in our top draw. It was coming from the sink plug hole. When i took it apart there was no rubber seal only a small ring of sealant. This had just fell apart probably when i had to clear a blockage at the right angle bend ( why put a right angle bend in a sink outlet pipe ? under the van and had wiggled the pipe going to the sink. I bought an ordinary plug hole rubber seal set for $3.50 and placed one of the seals under the sink between the sink and the fitting. It has stained the bottom of the draw and i was lucky i noticed it early, others may not be so lucky and destroy the ply draws. Surely a 20 cent rubber seal could have been used.