[John Rogers]

In the 38 years we have had our house I have replaced a lot of sink, tub and other drains. I was told by my friend who was a plumber years before that when a leak starts to replace everything from the sink to the tee fitting in the wall. As noted make sure the straight sections are all the correct lengths so the washer and nut will be able to tighten evenly to get a good seal. I usually start at the sink and loosely assemble new drain line and then loosely install the line into the tee in the wall. Next I sit the trap section next to both pipes and make sure the ends of those first two are about 1/4 inch from the end of their seating area. If they are too short, GET LONGER ONES, DO NOT TRY TO BEND THINGS. If they are too long mark the trap locations on each one, remove them and cut with a pipe cutter if metal or shears if plastic. Remember the pipe section going into the wall will shorten in relation to the outside. I usually go ahead and use paste pipe sealer and install it tight as you can cut the length later and it will be more accurate. I usually put the nut on the wall pipe with the seal ring, making sure there are no cracks or cuts in it then tighten the nut hand tight. I then drop the new drain from the sink through, making sure it is not too long or some how I miss-measured! Put the nut and seal washer on it the tighten and seal the drain inside the sink. Then tighten the nut hand tight and make sure all connections look just like that drawing earlier. If they do tighten the nut with plumbers pliers snugly, not 500 foot pounds or anything! Good luck