While having a leaky fuel line repaired by a dealer or professional repair shop can cost more than $500, the parts involved in the repair are not costly if the vehicle owner performs the repair himself. Most fuel line leaks can be patched or otherwise repaired without replacing the whole fuel line, though replacing the fuel line is the longest lasting repair.
The most common place for fuel lines to leak is at the fittings, where nylon hoses meet metal lines that lead to the fuel pump or fuel pressure regulator. Determining the location of the leak is often difficult but is accomplished by visual inspection and by smell. Inspect the fittings near the fuel pressure regulator at the end of the fuel rail near the engine and near the fuel pump underneath the vehicle near the fuel reservoir. Look for rusted metal lines and inspect the ground where the vehicle is usually parked, as some leaks continue when the vehicle is not running and if that is not the case, the leak still is likely to drip fuel after the vehicle is parked and turned off.
Use a bucket to collect dripping fuel while working on fuel lines, which are best removed using open-ended wrenches. Metal fuel line and nylon replacement hoses are fairly inexpensive and found at any auto parts store but, if replacing long, factory bent metal lines, it is best to get them from a dealership.