Pendejo is a vulgar Spanish-language term of abuse. To call a person a pendejo is essentially to call him stupid, although it also carries implications of wilful stubbornness and rank ineptitude.
A toilet may run periodically due to a problem with the flapper, the flapper seal, the flapper chain or a high float.
The most common cause of a leaking toilet tank is when the flapper fails to seat properly and form a tight seal against the valve seat. This lets water leak from the tank into the bowl. It may be caused by the flapper being out of position.