I replaced all the stems in the bathtub. When I turn on the water and open the diverter valve to send water to the shower head, water continues to come out of the faucet (approx 30% of what it was prior to opening the valve). Water goes to the shower head but the tub really starts backing up because of all the water volume.

Here's the old valve

I am guessing that your faucet has three stems and handles. This is a Price Phister stem and sometimes it is hard to get them to not let water by. There should be a rubber washer and a plastic washer on this stem.

One hint is when you are putting the stem back into the valve make sure the stem is all the way open.

Thanks - I'll give it a try this weekend - I appreciate the help !

Well - that didn't work - less water now but still maybe 20% coming out of the faucet after opening the diverter