Fryer filter pump tripping under load

My Pitco filter pump keeps popping the GFCI about 90 seconds into a filter cycle; I’m seeing 118V idle, 109–110V under load, 6.1A on a 1/3 HP motor rated 4.8A, oil at 350F with fresh 2 micron paper. Megger shows 1.3 MΩ to ground at 500V and the run cap reads 18.2 uF on a 20 uF can — would you call this a failing motor, or have you cured similar trips with a cap swap or a wiring reroute away from the burner harness? I need a reliable fix before the Friday dinner rush.

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