[mjollnir81]

It's getting warm here in TN, and I have no functioning AC. Last time I was under the hood I noticed the AC compressor was totally covered in green sticky material. When I bought the car it came with one of those DIY "AC FREEZE" kits. I'm thinking the freon leaked out around the compressor and the leak detect/sealant is what covered the compressor. I dont own a vacuum pump but I could, HF sells 3 or 4 different kinds, along with manifold gauges and etc. I have a rudimentary understanding of how the system works and I've watched someone do it in the past (draw a vacuum and charge the system).

If I was about to do this myself, what are some "you must replace this most def!" type of parts? I was gonna order o-rings, and probably the orifice valve. I'm 90 percent certain the compressor works when charged. I have an old Ford truck I'd like to have the AC working on as well in the future, so buying the tools is definitely the option for me..

2006 Aero wagon, 195k.

 

[steve12955]

I have the gauge set and a decent vacuum pump I used when I replaced the compressor and failing hoses on an OG9-3. However, I wouldn't attempt to diagnose and repair AC on my three newer Saabs - too many (expensive) things can go wrong. At a minimum you'd have to replace o-rings, drier, orifice tube and if the compressor itself is leaking - the compressor - and maybe the condenser and hoses, etc.

But first, you have to find out where it's leaking. By the time you pay for a gauge set, a pump, refrigerant, dye and light, etc...you're easily at $150+ before you've diagnosed it and bought any parts. While I know you'd like to DIY, I'd spend $100 and have a pro diagnose it first. You can then buy and install the parts needed and save on labor cost and then have a pro recharge it for $100.

 

[mjollnir81]

I was also considering that option as well... Having someone diagnose it and charge it and me replace the parts.

 

[mjollnir81]

Got a quote for $1800. They said compressor is definitely leaking but wouldnt tell me much more than that. Said whole system needed to be replaced because it's contaminated. Second time I heard that. I knew the compressor probably needs replacing. Does it make sense that I need a condensor and evaporator and lines etc?

 

[steve12955]

If they saw evidence or you mentioned to them that an AC leak-stop product was used then they'd want to replace everything due to "contamination"- but I'm not sure they'd change the evaporator and lines behind / under the dash (tougher to access) - so it wouldn't really be the whole system.

I've never used leak-stop products so I don't know if they contaminate but I'd look around for someone who has experience flushing AC systems and ask if it can be done.

Edit: There's normally PAG oil in the system and it could be argued that oil contaminates but shops routinely replace components, vacuum the oil out and recharge without any issues. When you replace the compressor you have to add oil. I'd ask around for a third opinion.

 

[mjollnir81]

I never mentioned to them about using a stop leak today. I mentioned buying my own parts and got he got a disgusted look on his face. I'm thinking 1800 is way overkill. I doubt the evaporator is getting replaced. Condensor, compressor, expansion valve and dryer likely. Rockauto has a kit with everything i mentioned above for under 400 bucks....

 

[steve12955]

I just checked my garage supplies. When I DIY-replaced my OG9-3 compressor, a couple of hoses, and o-rings about 8 years ago I used a solvent product from Interdynamics - Premium AC Flush and Clean. As I recall it worked well. It's designed to clean the system of PAG and Ester oils and is used when you convert Freon systems over to R134a - but I'm not sure if it works on other contaminants.

If you're sure it's only the compressor that's leaking then maybe you could flush, do the replacement labor for it and the drier, and then get a shop to leak-test and recharge.

 

[redaero-wagon-2000]

you have to replace the receiver drier at least......maybe the expasion valve.
Fix leaks, change compressor.

Flush the system then vacuum. You have to fill the system by weight, not by pressure, because it has a modern variable compressor. Buy the refrigerant on line 134a.

 

[mjollnir81]

Reviving the thread for a moment. Since the AC was recharged it has been working well up till this point. Since it never worked while I owned the car I dont know how efficient the system actually works. With the air con set to 60F it does blow really cool, but not give me goosebumps cold. I do notice an improvement at highway speeds vs idle, and it is around 87F here. I had a Honda civic that the ac would freeze you out at highway speeds, but if you sat at idle the car was became kinda warm. Once you got moving it would get to freezing again.

Once this charge gives up the ghost I was considering buying a new compressor, dryer, and flush out the system, new o-rings etc. But it's worked up to this point... Maybe I dont need new components-just find and fix the leak?

 

[ksw92_mk2]

The behavior you mention normally indicates a low refrigerant charge (better AC performance at highway speeds).

The first thing I'd do is draw a vacuum on the system and see if it holds. If not, you have leaks and a dose of UV dye oil, a UV light and a base charge of R134a will allow you to find the leaks. Clean the compressor and condenser before you test with the dye. Just throwing parts at a problem can get frustrating and expensive.

You don't need to replace all the o-rings in the system. Just replace what you open and any joints that you've identified as leaks via the dye method. Lube them with compressor oil when assembling.