F-700 hydrolic brake problems

I have a 1999 F-700 S&P truck the problem I'm having is electric brake motor light and brake light are coming on. This started about a week ago so I started looking for the problem what i found was the master cylinder was leaking from the back so I replaced it. I bleed the master and all four wheels and still having the same problem. Could some of the brake fluid leak through to the booster and cause damage to it. I'm pulling my hair out over this never had this problem before after replacing the master cylinder. I would appreciate any help.
thanks