Replaced MOEN shower cartridge and it's dripping

[sergek]

My shower was slightly leaking for 3 months (yes, I had some other issues and neglected it). It was leaking from the shower head, so on the walls of the shower there are white calcium deposits. Anyway, yesterday I replaced it. And to my frustration, it still drips from the top. Much less than before, but it's not dry, as I expected. I tried to remove and re-insert it 3 times, before 3rd time I cleaned copper hole with the tooth brush, and open central water valve for a 2 secs to blow all debrees off. Still the same.. What should I do?
This is 11 y.o. installation.
Old cartridge have numbers on white plastic part: MOEN 158084 158085 30313 01:40
So I bought Danco 88675A (compares to Moen 1222). Is it the right one?
What to do, to stop this drip?
Now after I cleaned old cartridge in vinegar and tooth brush, could I install it back, or it's waste?

 

[Breplum]

Bad cartridge. Yes, you can reinstall the old. But the seals related to leaking at the water outlet (in your case a shower head) are internal. So cleaning the external cartridge does nothing.