Injector Cup / Sleeve Puller and Driver Tool Set for Caterpillar C7 and Caterpillar 3126 Applications. TamerX Diesel Products. Save yourself or your company time and money with our Cat C7 / Cat 3126 Injector Cup/Sleeve Puller and Driver set. The injector sleeve/cup puller threads into the old cups to remove them from the bore of the engine. The driver then sets the new cups into the bore where your previous cups were, reducing your labor time considerably. A must-have tool set for any diesel mechanic!