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R12 A/C Compressor seized, converting to R134a

Lando

Arthur Digby Sellers
Joined
Mar 3, 2011
Location
SLC
About a year ago, my AC compressor seized along with the clutch pulley. I just cut the belt and have had no A/C or power steering since. I would like to get both of those systems working again. I also want to retrofit to R134a, so recharging wont be a problem. I know that the system will have to be completely cleaned to ensure that no metal filings can damage the new components. I also, understand the receiver dryer should be replaced. Furthermore, I know that a new expansion valve should be fitted to retrofit my system to R134a. What is the best way to go about this? Can I simply fit newer 240 A/C components onto my 86? Or must I use an old compressor with fitting adapters and use the new expansion valve?

After I do all the replacing of parts, I will take it to a shop to the system flushed, evacuated and have the proper amount refrigerant added.
 
If the clutch seized the compressor may not have blown up. You'll know when you take it apart.

I converted my wife's former 86 244 to R134a and it had nice cold AC for years. I replaced the compressor (not out of necessity), all o-ring seals, the reciever/dryer. I added the adapter fitting to the low side of the compressor and filled the compressor with ester oil. That was it.

The car could hold 36 degree vent temps and that was in Guam. It would run coldest on fan setting 2 and no higher.
 
If the clutch seized the compressor may not have blown up. You'll know when you take it apart.

I converted my wife's former 86 244 to R134a and it had nice cold AC for years. I replaced the compressor (not out of necessity), all o-ring seals, the reciever/dryer. I added the adapter fitting to the low side of the compressor and filled the compressor with ester oil. That was it.

The car could hold 36 degree vent temps and that was in Guam. It would run coldest on fan setting 2 and no higher.

The belt wont turn the compressor at all. Wouldn't the clutch and the compressor have to seize for this to occur? If only the clutch was seized, wouldn't it just mean the AC was on all the time?
 
You're basically right on as far as I can remember. You'll need to grab an '86-90 PS/AC compressor bracket from a yard (this is where I get spotty; I don't think an 91-93 bracket will work, but someone else can confirm or correct me). You can get a conversion bracket off of ebay like found here, but I've never had much experience with these. They exist for a reason so I'm sure they're okay, just haven't looked into them.

The one thing I would also want to confirm is that the old hoses fit the new compressor. IIRC they don't and will need to be refitted or new one's will need to be grabbed from a yard, but check against your new compressor as they may work; I just can't remember definitively right now.

I used this conversion kit from FCP. It took a bit of time to get to me so you may want to factor that it. I think it comes from the mothership by the looks of the writing on the package.

I got my re-manufactured compressor from Compressors of the World on Ebay on sale for 129.00 including shipping. Looks like they've jumped up a few bucks in price, but not bad over all.

After you swap all that stuff out?the new conversion kit, o-rings, compressor, and potentially hoses?and the included oil and then suck it long and suck it hard. Or, take it to a shop and have them do a flush and do a leak test.

When I do the initial charge I always get the stuff with the UV dye in it. That way if it does happen to leak I know where to look. It's saved me a couple times.

Hope that helps!
 
So after doing a bit of research I have a few more questions.

First off, does the new R134a compressor bolt to the bracket that is in my 86?

Are the fittings to the compressor that are already on my car the same as the ones on the newer R134a compressor? I understand they may need a little bending, but I just want to make sure that the fittings are compatible.

I need a new receiver dryer because of the failed compressor, should I get the receiver dryer for a late model 240? or just a replacement for my 86?

What O rings should I replace?

Tasca lists two expansion valves, and from the pictures, one is actually an oriface tube. Will the R134a oriface tube fit in my R12 pipe?

Here are the parts I plan on replacing:
36000819 R134a A/C compressor
3545086 Oriface tube
1394712 Expansion valve
9131972 Receiver dryer

I also want to replace all the pipe seals / O rings, but they are not shown in this list of AC parts from tasca:
http://www.tascaparts.com/auto-part.../hvac-cat/condenser-compressor-and-lines-scat
 
Also, do i have to change the AC knob to a snowflake switch?
 
Also, do i have to change the AC knob to a snowflake switch?


No. You are combining two completely different systems in your thought process. An orifice tube is what takes the place of the expansion valve on a 240 system. You have either one, or the other. The snowflake switch just turns on the compressor. You already have that covered with your dial switch.
 
No. You are combining two completely different systems in your thought process. An orifice tube is what takes the place of the expansion valve on a 240 system. .

That is what I thought, from my experience with GM AC systems, but tasca listed both parts for a 93 240. :e-shrug: Thanks for clearing that up. Good to know I can still run the knob, because according to Arts website, it allows the driver to vary the duty cycle.
 
bump.

Still need to know what parts I should replace here. I'm pretty sure it's just the receiver drier, oriface tube and compressor from a 93 240 (R134a), from what I know about AC systems and from what I have read. However, I read in another thread on here last week, that the fittings on the newer style R134a AC compressor are metric, while the R12 systems lines to the compressor are standard. Do I need to replace the lines with the newer style also? Is that even possible?
 
Lando,

Replace:
Compressor
Drier
All o-rings
All hoses. Yours are decades old and aren't going to last long if at all.

Forget about the metric threads noise. It doesn't affect your system, only the '93's.

You don't have an orifice tube to worry about either.

You would benefit from a parallel-flow condenser, but that's going to be an additional expense that only you can justify. The condenser from a '93 can be fitted and is a PF design. It just uses a couple of different from stock hose ends to get everything pointed in the right direction.
 
Hoarding parts for this to be done before summer. Can't find any one who stocks 3522587 O ring. Does anyone know the dimensions and material?
 
With an internal compressor failure the entire system needs to be flushed completely. While a professional flush fluid is sold for about $35 a quart not being a professional I use brake cleaner for about $2.50 a can. While the expansion valve has probably blocked the majority of junk from the expansion coil it needs to be blown out completely as does the condenser.

Replacing the hoses is a very good idea just based on age never mind cleanup. You are going to have to take it all apart anyway to replace the 'O' rings. About the only way to flush the system is by hose or coil individually.

At the price of new Chinese compressors they are a much better solution than an used one.
 
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Also, don't go Gorilla when tightening these connections. Most are soft metal.

Use mineral oil to lube all Orings before you install them. All R12 conversions should us POE oil, rather than PAG (which is spec' for OEM R134a systems, not conversions.)
 
I used this http://www.rockauto.com/en/moreinfo.php?pk=5243814&cc=1287615&jsn=398

I flushed out the condenser and evaporator with brake fluid and compressed air based on Test Point's recommendation. I used one of the old lines to place on the evaporator with it out the passenger's side door so all the junk wouldn't be sprayed in the interior. My compressor was seized as well. I drained out the oil that came with the new compressor. I added the mineral oil from the drugstore and flushed it completely twice while rotating the pulley. Then I added FJC Estercool Oil to the compressor. I bought a cheapie vacuum pump and gauge on ebay, which helped to see where the fittings might be leaking.

The most frustrating thing were the mounting brackets to the ac compressor.

Take your time and you will have success!

http://www.rockauto.com/en/catalog/.../c+system+o-rings,+seals,+&+gasket+kits,13290

http://www.rockauto.com/en/moreinfo.php?pk=818144&cc=1287615&jsn=387&jsn=387

http://www.rockauto.com/en/moreinfo.php?pk=818362&cc=1287615&jsn=388&jsn=388

http://www.rockauto.com/en/moreinfo.php?pk=818615&cc=1287615&jsn=389

I bought a second set of seals just to be on the safe side.
http://www.rockauto.com/en/moreinfo.php?pk=3917766&cc=1287615&jsn=405

Mineral oil can be found in the drug store section of any supermarket; it is cheaper there.
 
I haven't tried it myself but I want to try the R152a refrigerant. It is supposed to be better than R134a and can be used to retrofit old R12 systems.
 
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