I have a 97 F150, v-6 4.2 l engine automatic. Recently I notice the a/c going from panel to defrost. Going to Columbus yesterday as long as the engine was under light load the engine/transmission was fine but when trying to excelorate or slowly down (no braking applied) it would jerk. I suspect a bad vacuum pump but I have no idea where it's located or what it looks like. Can you enlighten me?

 

There's no vacuum pump, it uses engine vacuum. Pull your battery and look at the vacuum lines behind it, one is probably cracked. That would cause the A/C issue. The tranny issue is something else, no vacuum involved, it's all electronically controlled.

 

The vacuum line was barely making contact. I cleaned it up and taped it until I can get a replacement fitting. It doesn't jerk and the a/c doors don' change positions underload.

 

You can cut out the bad section and splice it with standard vacuum hose of the right size.