Alright so I posted a while ago about a pretty clean roller I picked up before deployment but I’m back now and ready to start building a motor and installing it. Trying to get all the parts first so once I start I’m not waiting a week at a time for parts. Everyone hates that right. So the question is I’m swapping a lq4 into 01 Camaro z28. I have almost everything except for engine and trans. But I want to make sure to keep ac. What parts would I need to replace with them being exposed to the elements for about a year? I’m pretty inclined with mechanics but don’t know really anything about ac systems. Would it be easier to just take it to a shop after engine install and say rebuild ac system, or hook everything up and just take it to the shop to have lines vacuumed and system charged up? Thanks for any suggestions I’m advice.

 

How I do it...
The dryer needs replaced if left open to atmosphere, when your ready to charge the system install the dryer last then put the vacuum pump on and pump it down, I leave the pump on for many hours,, at the 14 inches of vacuum it will gradually evaporate any vapour out of the system. Use all new o-rings if possible.

The system should hold vacuum for a few hours after disconnecting..

I would consider having a AC shop do the fill so they get the right oil and refrigerant in there ,, R134 LIKES THE PRESSURES DEAD ON, the system will ruin seals if over filled and not work worth a hoot if under-filled.

 

is the dryer the only parts that “needs” replaced from being out? Yea having shop fill it seems like best option so it doesn’t stop working. I would love to learn more air conditioning stuff I just don’t have the tools to try it out or the want to change a whole ac system cause I didn’t put enough oil or r134 or left moisture.

 

Air conditioning is on the finicky side. Taking it to a shop is always the easiest route but certainly not the cheapest. As for whether or not you want to do it is up to you but here are somethings you need to consider:

You'll have to buy tools and equipment that you may not use again for years. For starters you'll need a decent vacuum pump, ac gauges, flushing tools, and an air compressor if you don't have one already.

As for parts you'll absolutely need is a drier (not optional), orifice tube (not optional), and a new compressor is probably not a bad idea if it's still original but that's up to you, mine blew out the orings on the compressor housing itself and I had to trash the brand new drier I had bought.

The work is not hard to do but is a pain in the *** and kinda tedious. You'll need to disassemble all of the lines and inspect them for ANY metal flakes in them, if they make it back to the compressor it will not last long. If you find metal then your compressor and condenser in front of the radiator are now trash. When you have all the parts you need you should buy some AC flush and flush all the hard lines and the evap core, I used some solvents and back flushed them. You'll have to then make sure all the lines are completely dry before you start getting everything put back together, AC hates pretty much anything other than PAG and refrigerant in the lines. You'll have to make sure you have o-ringed and sealed everything bolt in all the hard lines and the compressor with the drier being last since you don't want that opened to outside very long. You'll then pull a vacuum on your system for a few hours as mentioned earlier to make sure everything has boiled out, I ran my pump for 2 hours and left it to sit overnight to make sure the system at least held a vacuum.

Charging it is actually pretty easy honestly if you have flushed everything and gotten all the oil out and replaced the compressor. The new compressor should come with oil in it and you'll need to add or remove to get to the 9 oz (I believe not 100% sure), if it needs more you'll have to add it to the drier before pulling the vacuum. An empty system requires 24 oz. of r134 which is normally 2 cans from the usual part stores. After you're sure the car is holding vacuum you would start adding the cans using your gauges on the low pressure side as much as she'll hold, then you start her up and turn on the AC and let the compressor begin to suck out the rest of the can on the suction side. After 2 cans it should be good to go as far as charge which you can validate with your gauges and some graphs using outside temps.

I skipped over the little details like making sure you purged lines and how to hook up the gauges but a youtube search would be much faster than me typing a bigger book report.

So if you want to do all of the above then you can save yourself a buck and learn something new, but if you screw up you're buying another drier and 134a at the minimum and if you let moisture and junk in the lines you'll be replacing the condenser and compressor again as well and re-flushing everything and starting over.

 

thanks for the little write up man! It doesn’t sound all that hard just like you said tedious. I’m all about learning something new but the buying the tools
fot something I might do once ever 5 years, plus if I miss something I’ll be buying alll new stuff for the second time I’m probably gonna go with a shop. Even with it being a lq4 vs ls1 going in I should be able to take it to a shop and tell them I would like the ac system rebuilt just as if it was stock?

 

I'm sure a shop would be more than capable with that request. For me personally I'd want to order the parts myself so I don't end up with some piece of **** wing dong brand garbage from Autozone or NAPA, and I don't have to wait for them to order the parts and wait for them to get there. If you want to bring your own stuff give the shop a call before to make sure it's okay, some guys get pissy about it and some don't. Rock Auto has a few kits with all the stuff you need under AC Compressor & Component kit just make sure you know what you need before, some of the stuff under there has a condenser and some don't, you'll need one if it has any contaminates in it since it's a non-flushable part.