Fuel injector

A fuel injector, comprising:

• a housing having at least one return bore formed therein, said housing containing:
• at least one nozzle tension nut with a nut contact surface;
• a first injector module having a first contact surface;
• and
• a second injector module having a second contact surface, said first injector module and said second injector module adjoin one another and are disposed in said nozzle tension nut, said first injection module and said second injector module having at least one high-pressure bore formed therein leading through said first injection module and said second injector module for conducting fuel;
• said first contact surface and said second contact surface having a first space formed there-between defining a first gap adjoining said high-pressure bore;
• said nut contact surface and said first contact surface having a second space formed there-between, said nut contact surface and said second contact surface having a third space formed there-between, said second space and said third space together defining a second gap connected to said first gap, said second gap being sealed off relative to surroundings of the fuel injector;
• said return line adjoining said second gap for discharging the fuel that has entered said second gap from said high-pressure bore through said first gap.