Tub/Shower has cold, hot and diverter knobs installed 1969 during home build. There has been a drip for some time from the faucet and turning the diverter knob causes the drip to transfer to the shower head as expected. Recently the drip has gotten worse so I figured i would give it some attention. I came to the conclusion that if i installed a 100% shutoff valve behind the shower head I could stop the leak and simply keep the diverter turned to the shower head. This stopped the drip from the shower head and the diverter is keeping all water directed to the shower head, no drip at the faucet. So I thought I was good to go wiped up all signs of water and checked on it a bit later. To my surprise I see a stream of water running down the shower wall where the flange sets against the shower wall. Water obviously coming from the face of the valve through the screw on extension tube and out the flange. Both hot and cold are leaking like this. Had another thought and turned both hot and cold full on and all leakage stops. Now here is a question why when I have the bath water valves open keeping constant pressure at the shower head shutoff valve are the other faucets in the home slow to warm and water not hot as it was when tub water was off. I assume that by allowing the water to stay on but not flowing in the shower all I have done is changed the location of the shutoff from the hot /cold knobs to the self installed shut off valve.