If a valve has damaged keep grooves, it must be discarded.

• A. True
• B. False
• C. It Depends On The Engine
• D. Only If The Groove Is Very Deep

Answer: (A)

Damaged keep grooves on a valve compromise the only feature that secures the valve keepers. Those keepers sit in the groove to hold the valve spring retainer in place, keeping the valve properly seated under pressure. If the groove is damaged, the keepers can’t seat reliably and may slip out or fail, leading to loss of valve retention, improper valve operation, or catastrophic engine damage. Because this retention feature is critical and isn’t reliably repairable, the valve must be discarded. Even small damage can make reuse unsafe, so there’s no safe “depends” or “only if deep” scenario here.