I have what looks to be a 20-year-old American Standard Reliant faucet in my bathroom that recently started leaking. 20 years is great for scotch. It's not so good for hardware. I went to buy a replacement tube at Home Depot for the leaky cold water supply before checking out what's there; I don't think these hot and cold water supplies are meant to be replaced. And where's the nut holding the faucet hardware in place? There's just a mess of stuff up there. Thinking I might just call a plumber. Thoughts?