rear brakes

The rear disc brakes on my car keep rubbing. I've looked at the calipers and noticed the parking brake doesn't fully release. I sprayed some wd-40 on them to loosen them up and backed them off, but for some reason, they keep rubbing. If I take the the whole parking brake lever off and spring(there is a bolt holding it on) to lubricate and clean it up from all the crap that's in there, will it affect the regular brakes and will I have to bleed the them? I backed the cable off and still they keep tightening up on me.
Any help is appreciated({).