The KL5007NAV comes with two unique adapters that use standard shop air to create regulated pressure and a powerful vacuum. The regulated pressure forces the coolant out of the entire system quickly into the 20-gallon tank. After the coolant is out, closing a single valve allows a pressure test to be performed, diagnosing the integrity of the system. After all the necessary repairs are made, the pressure module is swapped out for the vacuum module. The vacuum creates negative pressure throughout the cooling system drawing the coolant through the entire system from the bottom-up. This eliminates the possibility of air pockets forming in the EGR cooler. May need Coupler p/n: 3688493C2 or for LT, RH and HX Series Trucks, use Coupling p/n: 4061202C1.