My old kitchen tap was connect to the Mains feed and has worked happily since the late 70's, I have replaced the sink and tap with a mixer tap with spray. But I am getting leackage from this.I have tried reseating the valve (blue plastic thing) but it still drips a little.... could the mains pressure be to high.... can I reduce is (as all the other taps are fine....) or is it the tap ?