7. Since the pump is mounted under the front of the bed and there are a couple of feet to the booster, I flared a short piece of 3⁄8-inch steel tube. I am going to connect the pump to the booster with the minimal amount of rubber hose needed. Rubber hose can get sucked closed sometimes when used in length in a vacuum system. With the flare on the end of the tube, the hose will fit real tight and not leak.