Kitchen Drain Repair

Remove the old pipes under the kitchen sink.
If there is a dishwasher tail piece or a plastic tail piece buy a brass dishwasher tail piece is it is much better.
The plastic dishwasher tail pieces do not work very good.
The hot water expands and contracts the plastic washer and nut and it usually leaks in time.
A little secret is, any time you put a nut on a tail piece or trap run the hot water and tighten the nut again you will be able to tighten it, because the hot water softens the plastic.
When you are replacing the trap if you can, throw away the plastic nuts and buy some brass nuts to use in there place and put little pipe sealant on the treads and reassemble and your sink should not leak.