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DIY & Home Improvement

NYC_SKP

(68,644 posts)

1. In my experience, black stuff has come from deteriorating black rubber parts.

Reply to irisblue (Original post)

Tue Oct 8, 2013, 02:55 PM

Oct 2013

These may include the flapper, the tank-to-bowl gasket, and the tank bolt seals.

There are no pipes inside the toilet, but there are rubber parts in the connecting hose and the wall valve itself.

I would recommend against using bleach or vinegar, as they are both solvents and each are able to dissolve certain materials.