What's wrong with the pipe? It's a hard line, so unless it has been bent, or it blew up, there should be no reason to replace it. Normally it is the high and low side hoses going to and coming from the compressor that start to seep refrigerant, and need to be "rebuilt" or replaced.
I would make sure you had enough oil in your compressor, as well as replace the o-rings on the hoses that attach to the compressor. I would also replace the o-ring on the pressure switch, just as a precaution. And yes you should replace your heater core, but no it will not effect your a/c charge. It will how ever effect the level of coolant you have in your radiator with it leaking.
I would make sure you had enough oil in your compressor, as well as replace the o-rings on the hoses that attach to the compressor. I would also replace the o-ring on the pressure switch, just as a precaution. And yes you should replace your heater core, but no it will not effect your a/c charge. It will how ever effect the level of coolant you have in your radiator with it leaking.
