Very stiff and dripping tap.

Dear Sirs,

I have recently purchased a second hand bath tap which is a old brass one, seems in good nick but it is extremley stiff to turn off and no matter how tight I turn it, it wont stop dripping. Would appreciate any advice!!!

thanks Burge.

p.s before I mounted the tap I flushed the tap out with hydrocholric acid,could this of caused damage?

Dismantle, descale, grease, new washer, reassemble.