I have a price pfister 3 handle shower (circa mid 70s) that when set to shower also lets water out of the tub spout. . When set to tub only, flow is completely blocked to shower head. I have replaced the seat washer and the valve seat with no improvement. There are no other replacement parts on this valve. I applied air pressure from the shower nozzle down to the diverter to test if the diverter was sealing and i could hear no bypassing air through the valve. When pulling the valve back out i can physically see where the washer has compressed against the seat.
Any idea why i cant get the divertor to block flow to the tub?