We have Phoenix and were able to get some parts at the hardware store. I remember there was a plastic ring along with plastic teeth that held the trim piece down. 3/4" deep socket as I recall. But I forget how I got down to the hex on the washer "cartridge" other'n I broke a couple of the teeth. I replaced our kitchen sink and vanity faucets with Phoenix from Amazon. But at a visit to Home Depot, I later found they had at least some complete "cartidges" (that whole brass hex part, washer, o-rings and all) for Phoenix.
Following pic is from Amazon.
I replaced Kitchen and Vanity with the type pictured, which is a 1/4-turn "washerless" design. I parted the old ones out, keeping Knobs and Cartridges, since we still have washer-type Phoenix Shower and Outside Shower faucets.
Reluctant to try to change the washer in a faucet when I can't get a Cartridge since I've had the screw to come apart at the head or break off in the brass cartridge. If I can get the screw out I'll try to replace with stainless, new brass, or at least some compound on the treads.
The washer seats in our Phoenix faucets were plastic, molded into the base, so they weren't subject to pitting and leaks from there. If you've got a drip, should be from the washer.
If you decide you want to repair what you have and need a cartridge, let me know. I'll work on the four I have and see how many are salvageable.
