This handy little Vacuum pump from Stahlbus is compatible with the Stahlbus range of bleed valves and is the perfect answer to filling / flushing brakelines, being quick, clean, easy and safe. To use the vacuum pump simply switch the screw valve to 'Filling' mode (unscrewing by 2 turns).Follow Stahlbus' simple step by step procedure for trouble free filling:Firstly open screw valve 2-turnsSqueeze bellow...and place on top of screw valveBased on the totally gas tightness of screw valve...and despite of the vacuum inside, no air can enter through the thread of the bleeding valve into the braking systemLet bellow expand...due to the vacuum the brake fluid is drawn into the line...until the entire brake system is filledAfterwards...close screw valve with two turns...before removing the bellowImportant...Top up fluid as required