Question: how do you know when you need to replace your toilet?
Answer: There are cracks in your tank. If you frequently see a puddle of water around your toilet, this could be more than a simple leak: You could have cracks in your tank, and the toilet may need to be replaced. ... 
You have an old toilet. ... 
You feel it wobble. ... 
You've had to fix it often. ... 
You have a round bowl.