I'm in the process of pulling my engine to fix some engine leaks and do some other things. I've done most of this stuff before but I've never learned about the AC system other than the past hour watching Youtube. My truck is a 2000 Jimmy and the AC hasn't worked for years. I figure that I'll make sure the system is completely gone through and working for next summer but the question is... should I replace any parts of the system now just because everything is apart for pulling the engine? The AC condenser looked pretty rough when I pulled the rad with a bunch of the stuff between the fins falling out. Would it be wise to put in a new condenser now and leave everything else until next summer? Or should I just replace everything at one time?

Another question, can I just disconnect the fittings to open up the system? I'm guessing there is none/minimal refrigerant in the system as it hasn't worked in years.

 

If you want to keep the Blazer, I'd suggest replacing everything except the evaporator that can be flushed in place.

The condenser passages are too narrow to be flushed.

I was able to borrow all the tools I needed from the local Autozone.

I was able to do a full AC system rebuild that has worked well for quite a while now. I did a writeup of it in my build thread.

 

I have seen a "kit" at rockauto. You should replace the accumulator and the orifice tube and all the O rings at the fittings/connections as a minimum. The compressor is a probably replace, but it might still be good. Only way to know would be to pull a vacuum on the system and see if it holds. The condenser coils are also included in the kit and should be replaced and of course the PAG oil and refrigerant.

My '02 is headed for the AC shop on Tuesday as it has greatly reduced cooling down now, my cheapo gauge shows low on refrigerant. It has been over five years since it was last done, so not bad at all. I know there is a small leak somewhere, but if I get another five years, I will be happy.

Good Luck.