Before I try to repair this, I want to understand what's going on so I don't fix the wrong thing or cause a larger leak in the bathroom sink.
Our house was built about 20 yrs ago so it's modern plumbing, not plumbing for a house from the 1940s. When you turn on the hot water, for some reason, water starts leaking from the base of the cold water faucet. Why would this happen? I can understand if i turn on the cold water and it leaks from the faucet but not this.
I was going to change the cartridge in the cold water to see if this fixes it but I'd like to know why this funky behavior is occurring before I start doing something I shouldn't be doing and causing a bigger problem.