Sometimes sink drains get clogged and drain slow. If you have plastic-type trap connections to the drain, you can tell if the trap part is clogged without taking it apart. Simply hold a strong flashlight against the side of the drain and you will be able to see right through the drain almost.
Here are a couple of pictures that show what debris inside the trap connections looks like.
Charles Buell, Seattle Home Inspector
Looks pretty hairy in there.
Hey Charles, I made a video of an s-trap siphoning water using the same technology- http://www.youtube.com/user/inspectorreuben#p/a/u/1/iKICsa-Jnyc
Cool video Reuben—-if it didn’t have to drag it uphill so high it might have succeeded 🙂