When it comes to fixing water-related problems, there ISN'T such a thing as a quick-fix. And if there is, you'll eventually regret it. (Remember the story about the Dutch kid and the leaking dike??? Use that as a 'guide' ...)
You need to find out HOW the water is getting through the mortar. Is it running down the outside wall? If there a missing or incorrectly hung gutter? Once you address the source, then you can fix the mortar the RIGHT way. You'll need to repoint it.
Don't go 'covering' or sealing up the brick. Brick is a fired clay that WANTS to breath. It's a material that's soft on the inside and hard on the outside. If you seal it, it won't breath. And if it won't breath, you'll have moisture and condensation problems.
My best to ya and hope this helps.
Jay J -Moderator
PS: God Bless AMerica!