Secondary Air (Smog) Pump Guts
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The 2 rear vent holes visible in the upper right of the case allow penetrating oil to be used to free a stuck pump, and flowable grease to keep it moving. But if the cast Iron drum rusts too much, the pump must be disassembled & sandblasted to restore its movement. Graphite paint (like EZ Slide) can be applied where the drum rubs the case to prevent galling & seizing.
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