Howdy, I just found out that I have to have my heater core replaced in my truch as it is leaking. I have done a little research on it and doesn't seem like it would be too difficult or technical. However, the question I have is that the mechanic that diagnosed the problem told me that in order to replace the core, the A/C had to be evacuated and recharged. In my research, some others who have done the job on similar year 150's have told me that you do not. Can anyone offer input on this? Will I need to do that to the A/C or is the mechanic trying to get an extra couple hundred out of me? They quoted me $650 for the whole job (including freon). Also, is this job as straight forward as it seems (taking the glove box off, pulling the heater core unit out and replacing it) or is there more to it that i haven't found yet? Thanks in advance. Marc