I have a 2 handle bathroom sink faucet made by Jado. There was a slow drip at the spout and I determined it was happening through the hot handle.

There wasn't any evidence that the handle area was leaking so I believed the top o-ring of the cartridge was working and either the internal mechanism of the cartridge or the seat seal was the cause of the leak. So, I need a new hot side cartridge, right?

Ok. I bought the appropriate replacement part online, like this one - [www.americanstandard-us.com]#

I put it back together and there is no leak up from the hot handle, but the drip at the spout is even worse now. I fully tightened the cartridge into its seat without any observable problem. Did I do something wrong? Could I solve it another way? Add lubricating silicone on the bottom seat? Any thoughts?

Can you switch hot and cold cartridges and see if the leak follows the cartridge or stays on the hot side?

Good idea. I'll try and see if the housing for the cartridge on the hot side is the cause. I'll make the cartridge switch tomorrow and see. Thanks.

I wasn't able to deal with this faucet since the last post, but a change has occurred.

Without doing anything for 36 hours, the hot side handle still allows a drip at the spout, but the rate has noticeably changed. It was leaking at a rate of one drip every 4 seconds at first installation, but now, after a few open/closing actions during that 36 hours, the rate is now one drip every 40 seconds. Obviously, I need it to completely stop the leaking, but the change is noteworthy.

Does this behaviour change point towards a possible cause?

Not to me.

as rubber washers and "O" rings get wet (from a totally dry stage) they swell up a tiny bit. so sometimes a dry faucets innards will drip a little when first turned on but get better as the parts get wet.