Furrydogs

I've spent several hours reading all of the forums for replacing a bad heater core and I've successfully removed the dash and pulled out the heater core box. Now I just want to make sure I get things right before putting the new heater core and A/C Evap back together.

First off, I wasn't going to replace the A/C evaporator as it worked just fine and was the original part. But, most folks said to replace it while I'm already in there. Sure hope the new one lasts.

Anyway, as I was taking out the evap, there was this small copper tube connected to a wire that went about 4 inches into the core of the A/C unit.I pulled it out and just the wire came out first, then I was able to pull the copper tube out.

Will I need to re-insert this into the new evap and if so, should I buy a new one of these too? How important is this part and will it cause the A/C not to work if it is malfunctioning?

Finally, are there any "gotchas" I need to look out for when putting this all back together and bolting it up to the firewall? I really, really don't want to do this again. I've got a picture of that copper tube thing.

In case anyone is thinking about doing this job, feel free to ask any questions about how it has gone for me so far. On a scale of 1 to 10 for mechanical ability, I'm probably a 5 and the tear down of the dash wasn't too bad. I guess I should wait until this job is complete before patting myself on the back.