A device to suction fuel from a fuel injector and a device to attach a fuel return line to a fuel injector with a C-shaped main body partially encircling the fuel injector having two retaining arms which abut the fuel injector and grip it from the back at least to a small degree, with a connector coacting with a drain passage of the fuel injector and at least one connecting fitting for the fuel return line. The connecting fitting and the connector are fluidically connected. The free ends of the retaining arms have a first section in which they are angled towards each other and towards the base of the main body.