For a wear indicator type ball joint, when the grease fitting boss is flush with the base: B. The ball joint should be replaced.
A wear indicator can be defined as a type of technology that is designed to alert and warn a car owner or driver that the car's brake pad is needs a replacement.
Generally, a wear indicator is designed and fitted with a small boss. Thus, this small boss would continuously recede into its housing as wear occurs. However, when it recedes into the cover plate or flush with the base, it simply means that the ball joint should be replaced.
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