Bizarre faucet leak issue

My kitchen sink has recently started leaking intermittently, but in a weird way. When you turn on the hot water knob, water leaks from under the cold water knob, which makes no sense. I’m pretty handy with basic repairs and comfortable with a wrench, and I don’t want to pay for a plumber. Is this something I can fix, like a worn-out washer? Should I just replace the entire faucet?

It’s a very basic two-knob-one-spout faucet, kinda like this one. The labels on the knobs are almost illegible; I think they say Eljer, but when I looked up the name it seems like an upscale brand, which my faucet certainly isn’t.

I think the leak is between the upstream and downstream sides of the packing on the cold water knob’s shaft. I don’t know why pressure on the downstream side of the cold valve created by opening it doesn’t cause the leak, unless the shaft is a little uneven.

Yes, that’s a classic sign of worn packing on the cold side.

You might be lucky, and all you need to do is pull off the cold handle then snug up the packing nut. If this stops the leak, wonderful, but it will probably only work for a couple of months until the packing wears down further.

If you’re not lucky, you’ll need new packing - here’s where it gets weird. You might be able to get just the replacement packing material for a couple bucks, or you may need to replace the stem - unless you can go to a real plumbing supply shop or a good hardware store that sells individual washers and seals, you may be better off replacing the entire faucet.

it is a mixing faucet so hot or cold pressure is present on both sides of the valve when either is open.

sounds to be packing on the cold side.

OK, thanks guys! I’ll dig around my local hardware stores and see what they have.

JRB