I am trying to fix my leaky shower. When I turn the shower on most of the hot water goes down the drain. I have removed the screw that holds the handle on but I can't get the handle off. It will turn to the off position or to the on position. The pipe that goes into the wall will loosen but the handle will not budge beyond the off position. Does anyone know how to remove this? I don't know the brand or even how old it is,my house is about 50 years old and it might be original to the house but I kind of doubt it. Any help would be appreciated.

Spray it down with wd40 and go to your hardware store and pick up a handle puller... they will know what u are talking about.. hope that helps

Follow plumbermans advice and pick up handle puller,(see image). Good luck, Tom