In a sink there are lots of connections which could be sources of any leaks in the sink. However a leak that comes and goes and becomes more prominent when the sink is full is mostly from a leaky sink strainer. A sink strainer leak can be repaired.
How to fix the leaky step by step.
Step 1- Turn off the sink water supply. Clear the working space. Then put a bucket underneath the sink to capture any leakage.
Step 2- Use an adjustable wrench to remove the nut at the slip joint this is the holding the sink tail at the end of the strainer body. Loosen the slip-joint nut at the lower end and slide the tail piece down to create clearance.
Step 3- Using pairs of adjustable pliers loosen the nut that holds the strainer in the sink.
Step 4- After removing the friction ring; remove the strainer body from the sink. Put the friction ring in a safe place for reuse unless there was a new friction ring that was included in the new strainer. Sink using a plastic scraper and paper towels scrub the strainer
Step 5- Roll a lump in your palms to make the plumbers putty and put the lamp in on the sink drain opening.
Step 6- From beneath the sink place the gasket then the friction ring, then the strainer body after which you tighten the nut. The excess plumbers putty should be cleaned.
Step 7- Look at the old slip joint to ensure that the washer will fit in the space in between the strainer and the tailpiece. If the washer is broken or has signs of wear and tear replace it. Slide the tail piece in position and tighten both slip joint nuts.
Step 8- You can now add water in your sink if there are some small leaks, tighten the nuts after which the leakage stops. You are now ready to use the sink.