I installed a Liberty waste pump in basement for toilet to run into city hook up eight feet up. The line is 2 in. sch 40 and wye's into the 2 in sch 40 from kitchen drain upstairs about 16 feet or so down line from the kitchen drain. I'm getting a girgle in kitchen drain when pump runs in basement, nothing is coming up into sink just the girgle. Any direction would be much appreciated. Thanks