No offense but I fully comprehend the suggestions that mark and tester have given. The problem is that I did not reveal that there is no nipple left to drill out. The machanic had clamped the hose over what was left of the nipple. When the hose came off what was left of the nipple came off with hose. I suspect that when the mechanic broke the nipple it exposed it to corrosion after he clamped the hose back on to what I guess to be a nipple no loner than maybe one fourth of an inch. My question of the suggestions given is how to thread a hole in the neck that seems fairly thin a bit corroded on one side of the whole. Is that a metal thick enough to be able to thread? I was on a road trip and was 7 hours from home. Otherwise my first step would have been to take it back to the mechanic. When he was finished replacing the water pump he pointed out the clamp holding the hose to the nipple and explained that the nipple had partially broken but the clamp should hold. It has for almost a year. However if had known at the time that the nipple had broken off so close the neck I would not have accepted his fix.