I took a portion of my kitchen sink pipes apart today to unclog one of them and THINK I put them back together just the way I found them. I had a problem with the end of the "J" bend (not the top) but got it mostly corrected. The bend does not appear to leak at the time I run water but, if I come back and check later, there is about 2 oz. of water in a bowl I have under the "J" bend. Any suggestions?