Howdy,
First I wanted to comment that you've done a very nice job on this site/forum and thanks for setting it up. Also if the answer to my question can be found somewhere on this forum please feel free to let me know and/or provide me with the link and I'll be more then happy to read over it.

I have a Bradley bathtub fixture in my home, PVC pipes probabaly 15 - 20 years old. It's a single handle that must be pulled forward to allow water flow and if you turn it to the left you get hot water and right to get cold water. Suddenly it seems that the hot water pressure is very very low. If you turn the knob to the right the cold water comes out fine, but when you turn it to the left hardly any hot water comes out. Same with the shower.

Any ideas why this may be happening and what I can do to remedy it and/or someplace I can get a diagram for this system.

Thanks for your time