Faulty part. Either get a new one, or, try to seal this one. Look at the casting real well to see if there is a crack. If it looks good, you could try some teflon tape around the plug, but, I think I'd get another one.
Thank you Teflon tape fixed it but now my rpm goes up when I apply the brake sounds like a vacuum leak hoses a good start? Have you read about people rebuilding the brake booster?
