I recently replaced my bathroom sink and the new drain pipe isn't threaded like the older one. So instead of a connection to the P trap with a threaded male/female piece and a tightening ring, the new drain simply slides into the P trap piece. This is where the leak is happening. I tried to use silicone to seal the open space but if running the water on a higher pressure, or if soap is used, the leak is immediate. What is the best way to eliminate the leak? Help!
Note: Both new and old piping is PVC.