Go off for servicing (6)

I believe the answer is:

repair

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'go' is the definition.
(I've seen this in another clue)

I don't understand how the rest of the clue works.

(Other definitions for repair that I've seen before include "service" , "Mend - go" , "Restore (something) to good condition" , "Restore after damage" , "Restore to working order" .)

I've seen this clue in the Evening Standard.

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