Temporary leaks occur when the sink is in use. These leaks are most prevalent in fixtures with dirty or worn-down O-rings, the seal at the faucet base. According to Fluid Power World, O-rings are the most common fluid power seals for preventing leaks. Constant leaks continue even when the sink is off.
How much do plumbers charge to fix a leaky faucet?
National Average Cost $280
--------------------- ------------
Minimum Cost $75
Maximum Cost $850
Average Range $125 to $350