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jshow816 05-26-2014 03:04 PM

A/C Questions
Hey guys, new Camaro owner here with a question. I recently bought a built 96 Camaro with a non functioning A/C. The previous owner turned the A/C condenser into a transmission cooler. One of my first updates to the car will be putting the A/C system back together and installing a real transmission cooler.

Some background info: The car was originally a 3800 v6 but was swapped for a '94 LT1. After doing some researching online, I learned that the v6 evaporator is not the same as the LT1. Previous owner told me he had functioning a/c after the swap, so I'm assuming he replaced the evaporator from the donor car, but I'm not sure how to tell..

I plan to put the A/C system back together and install a real trans cooler at the same time, hopefully.

I've linked to a picture of the current set up, I am completely new to ac work, so I would like any advice you guys might be able to give me regarding the repairs.

Thanks in advance, this place has been a godsend since purchasing my Camaro.

Z28Freak86 05-26-2014 03:29 PM

Re: A/C Questions
Going new is always good when doing AC work. You can use old hoses and what not, but get a new evap core Receiver Dryer for sure, then the compressor should be new or manufactured. Most places online have deals to give you the compressor and the dryer for a decent price. They try to sell you an orifice tube, but our cars dont require them. Instead, the Freon is expanded in the expansion valve near the firewall.

I say buy everything you need new cause its easier then trying to flush everything out. No matter what, receiver dryer has to be new, as that has the function of pulling moisture out of the system, so if its exposed to the atmosphere for a period of time it will just be ruined. New orings (7 bucks) its good insurance for a leak free system. Once everything is installed, take your time and properly vacuum the system. It took me almost a week to get mine right cause i had a slow leak at the high side valve. I got my vacuum pump and manifold gauges from Harbor freight (good price, worked very well), and let the system sit in a vacuum for 18 hours, then pulled another vacuum to make sure the system was clear of water. Then let the freon in and feel the air!

Z28Freak86 05-26-2014 03:30 PM

Re: A/C Questions
looking at your picture, your pipe has been cut going to the receiver dryer. That would need to be replaced. Then from the dryer, there is a small pipe that goes between the dryer and the condenser, that has the high side valve on it. Im not sure of the condition of the hose that connects the expansion valve to the compressor, which also connects the compressor to the bottom of the condenser, but if it is in good shape, put new orings on it and clean it out. I just used some brake clean and compressed air to make sure that it is clean.

jshow816 05-27-2014 09:24 PM

Re: A/C Questions
The compressor is still mounted on the engine, both of the hoses coming out of the back are cut and connected together with a piece of rubber hose and hose clamps.

Do you think I should replace the compressor? Is there any way to test it?

Z28Freak86 05-28-2014 03:10 PM

Re: A/C Questions
Ive never tested one before, but as long as it clicks on when you command it to, then it should be ok. But i say just replace it because if you get that whole thing put together and try to charge it, and the compressor does not work, then it will be alot of work to have to tear that thing out anyways. They are like 160-180 bucks for a rebuilt one and they have a 3 month warranty. Who knows what is going on with the inside of that pump

jshow816 07-07-2014 06:45 PM

Re: A/C Questions
Sorry been sidetracked with other issues on my car...

So at this point I think I need to replace all the lines for the AC system under the hood (compressor, condenser, evap core, etc..).

Does anyone know if the lines for the LT1 AC system will connect and work with the evap core box on the firewall from the 3.8 engine that was in the car originally?

I can get all the parts (minus the dryer) from a yard about an hour from me he has LT1's and 3.8's on the lot, but its an hour drive from here and I don't want to buy a bunch of stuff I won't need.

Also, the blowout diagram of AC system on shoebox site shows 2 harnesses connected to the AC system by the firewall, my car only has one the one connector that you can see in the pic I linked, a grey, black and red wire. Am I missing a plug somewhere?

Sorry for the long winded post, I'm decent shade tree mechanic but with the engine swap and AC work I'm mostly lost.. Thanks for the help!

bobdec 07-08-2014 03:24 PM

Re: A/C Questions
This is going to get complex. The '96 3.8 used an orifice valve not a mixer valve, this makes and the hook up to the evaporator different than the 5.7L mixer valve setup. Also the high line has to accommodate the orifice valve. So you need '96 3.8 lines to hook up to the evaporator.. However in the 5.7 lower pipe (return line) from the evaporator goes directly to the compressor which is in a different place on the 5.7 than the 3.8. . The 3.8 has the dryer in the low side line while the 5.7 uses the high side . Guess I'm saying the setup will have to be custom. Also in parts pics the condenser coil fittings look different, I may be wrong on that. Job is not impossible but much more difficult as you may have to get some of the lines custom made. Unless there is a conversion kit out there.. .
'96 3.8 ac parts ..

jshow816 07-09-2014 09:55 AM

Re: A/C Questions
Thank you so much for the info. So if I get the evap box on the firewall, along with all the underhood lines from an lt1(ill be replacing the condenser) it should all bolt up then right ?

bobdec 07-09-2014 12:37 PM

Re: A/C Questions
Never got involved in a 3.8 to 5.7 AC conversion. Do not know if the 5.7 evap coils fits a '96 3.8 HVAC setup. If it does then you will need just about everything in this pic ref However my '95 Z28 does not have items 36,37,38,& 39. The '95 Z28 only has one AC pressure sensor and it's in the high side 15-18 in the pic. My compressor recently bit the dust and I threw in one of these Chinese setups New Automotive AC Compressor Kit 20178 Includes Drier Expansion Device | eBay came w/dryer, mixer valve compressor, seals, o-rings (only had 4 1/2 inch, was short 2). People will advise against a $160.00 compressor, I'm a gambler !! Don't miss the 2 item #23 mixer valve mounting bolts, they are metric thread allen head that recess into the valve (#22), not easy to find.

jshow816 07-09-2014 11:24 PM

Re: A/C Questions
Alright thanks man. Thanks for clearing up the 2 harness thing. The one AC connector i have under hood is the same in one of the pics on Shoebox website. Looks like I'm going to go ahead and purchase the entire AC system out of an LT1 donor, go with new condenser, new dryer and hope my compressor works. Using freescan when i turn the ac on it shows PCM commanding AC. So *hopefully* within the next few weeks I'll have this working.I'll have pros flush the system and and pull vac on it.

I'm sure I'll have more questions once I get parts.

Thanks again everyone.

bobdec 07-10-2014 08:50 AM

Re: A/C Questions
That compressor sitting in open air and not spinning for ??? would worry me. It's a PITA, but I would at least pull it and drain any oil left in it. Buy a 8Oz bottle of Pag 46 viscosity (you can use 100 but 46 is thinner), put in 4 Oz and test spin it by hand a few turns to get the oil to flush through the compressor, drain it, and repeat with other 4 Oz. If it's exceptionally hard to spin or grinds you got problems with it. Then drain and pug the holes with tape or something to keep it clean. The OEM system called for 8 Oz pag 100 viscosity. I'd put 6-7 Oz (runs cooler w/less oil) in the compressor before re-installing it and sealing the lines up. Make sure the shop purging (vacuuming) and charging the system knows the correct amount of oil has been added and they do not add any additional oil.

PS: Assume your PCM is a OBD1 since you are using FreeScan.. get a copy of GaryDougs Scan9495 free software. It displays the AC pressure sensor, a good tool if you don't have AC manifold test gauges. Lets you now static pressure, high side pressure and reads the temp from the sensor mounted on the evaporator coil (make sure you connect that up when you swap in the 5.7 evaporator). Since 5.7 does not have a low side sensor that info is not avail w/o a gauge. Also displays AC request, clutch picked and has an actuator section to manually pick the AC clutch (assuming you have 134 in it).

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