There is a fungal disease that attacks red bud trees called Botryosphaeria canker and dieback. Here is a link to a fact sheet on the fungal disease. I can't diagnose the disease from pictures. Someone should see samples. There are a couple things I can suggest. You can call a licenses arborist. You can find one nearby in the zip code database of the International Society of Arboriculture. You can also contact your Montgomery County Penn State Extension and see if they can help you. Penn State has a plant clinic where they test samples, but I'm not sure about trees. Here is a link to a Penn State publication on Botryosphaeria canker, On the left side of the page is a link to the plant clinic. Someone should be able to help you there.