Leaking frost plugs

If you can't get into a tight spot to tap in a new steel or brass freeze plug you can always install some of those rubber freeze plugs. I've installed a few over the years and none of them have gone bad or fallen out, but I would consider it a temporary solution. You can pick them up at just about any autoparts store and all you need to install them is a wrench, hence why they're good in tight spots.