Toilet runs periodically

[bmicahdowns]

Novice here -
My toilet keeps having to fill itself up every hour or so. I checked the cap and it appears to be in good condition. Not sure how old the toilet is (at least 8 years). What can I do to troubleshoot?


As an aside - Just under where the cap seals there was a black ring. When I touched it, it spread like mist into the water and looked like ink. (Picture) What is that and is it deteriorating?

 

[Twowaxhack]

The black stuff is the rubber breaking down in the tank. It’s fine.

the cause of your tank filling up is because the tank is losing water.

It’s most likely just the flapper leaking. (blue in your pic with the chain ). Just replace it with a new one.

Make sure the little hose ( refill hose ) stays above the water level in the tank. This refill hose extends from the fill valve (ballcock) and is directed into the white flushvalve tube and is usually held in place by a clip.

so at the least you need a new flapper and possibly adjust your refill hose if it’s not in its proper location.

The bolts that hold the tank to the bowl appear to be rusting. Eventually these will need to be replaced.

snap a pic showing all the tank parts.