There are at least 3 possible sources of the leak, depending on the design - first find what is leaking.
Determine where the leak is and fix it. If it is where the drain seal against the sink, take it out and put a ring of plumbers putty around it and reinstall it. Any other connection is going to have a gasket at the joint or it may be that a joint is not tight enough.
how do i fix a leaky sink
I have a waterline leak at my home from the street to my home....can I get a grant to fix this leak?
What kind of leak and where is it?
If this is a sink leak, turn off the water source. Then take apart the pipe assembly looking for any blockages or holes and seal them up. If it is from a larger source, it is best to call a licensed plumber.
You have to determine the source of the leak then decide on how to fix it.
You will have to locate the source of the leak before you can fix it. Re-post with your findings.
Yes, separate gaskets for hot and cold. Hot usually goes first. It's easy to fix for about $4.
You don't fix the leak on the water tower. It is not part of the island quest.
If you are having issues with leaking under your sink, it could be as simple as a loose pipe fitting. Try first to tighten all of the screws. If you still experience leaking, you should contact a local plumber.
fix the leak
depends where around the tranny the leak is