The answer to 'when to replace leak repair' is that you should typically replace a leak repair if it continues to leak or fails within 1-2 years. Leak repairs are often a temporary solution, and the underlying plumbing issue that caused the leak may require more extensive repairs or replacement to prevent future leaks. If a leak repair is not holding up, it's best to have a professional plumber diagnose and address the root cause.
Factors that may indicate it's time to replace a leak repair include recurring leaks, water damage, or if the repair is no longer effective at stopping the leak. Replacing a leak repair can be more cost-effective in the long run than repeatedly repairing the same issue.