r134a conversion?

[bigwillie]

I was just wondering how many people have done an R134a conversion on their car. I have an 88 Bronco II. My a/c (R-12)needs to be charged so I figure I might as well convert it as long as I have to charge it anyway. Has anyone here done it? What kind of results have you had? Do you think I'd be better off just using one of those R-12 compatible refrigerants? I've recentley heard that people who have converted to R-134a have lost a/c performance, would it be easier to use a refrigerant compatible with an R-12
like this autofrost
(you have to click on products and then you will see the autofrost)

 

[sbc350gearhead]

I converted my mother's saturn to 134a 2 years ago. The A/C works great.

 

[kenw]

I've done several r134a conversions. No noticeable difference in cooling (note I'm in Houston).

I do know people who have used the equivalents and are very happy with it. I would think the compatibles would be easier.

 

[The_Jeff]

I'm under the impression that there aren't any R12 replacements you'd want to mess with.

You can use propane for example; it would even work, but it's way too explosive for the job. Automotive refrigerants are "only" moderately flammable for safety reasons.

I wasn't catching an ingredient list for that autofrost stuff, but it's probably a rather dangerous, flammable brew. If it were so good, they'd sell it in every walmart for the people who don't want to bother retrofitting.

 

[Chris142]

They are coming out with new laws all the time regarding the use of replacement refrigerants. Personally I wouldn't use any.

According to one of the trade magazines we get at the shop it's now illegal to use anything other than R-12 or R134a in an R12 system.

Also many replacements are a blend of 2 or more refrigerants or possibly flammable substances.

It's illegal to mix refrigerants because most shops can't recycle a blend w/o contaminating their whole batch. So it ends up released into the air which is also illegal.

Any refrigerants containing Propane, Butane or any other flammable gasses are illegal in all 50 states.

Your lucky. Fords work great with 134a! Flush the system with fast drying A/C solvent or mineral spirits. Replace your Reciever drier and use a green Orface tube instead of the red one for R-12.

Check the hiside hose for oil sweating which means it's leaking and must be replaced. Replace all O-rings and charge ports.

Use 3.5 oz of Ester oil per lb of refrigerant.

Use 85% of the R-12 charge with the 134a. So if it holds 2 lbs of R12 you need to use 1.7 lbs of 134a.

 

[punisher]

You will lose approximately 15% of your AC capacity moving to R134 from R12 with no other changes. It's just physics. That is the reason FoMoCo went to higher capacity condenser cores on R134 equipped vehicles. Most don't really notice the difference.

Chris142 laid it out. New o-rings and a new accumulator/drier are almost mandatory.

 

[paulo57509]

There's some good info at this site:

http://www.autoacforum.com/

 

[Kestas]

I converted two Mercurys to 134. Both blow cold... at least enough for Michigan summers. One car is lost. The other is still blowing cold after 3 years. Follow Chris' advice. Do it right, do it once.

 

[bigwillie]

I'm now thinking after all your comments it would probabley be easier in the long run to just convert it and not mess with all of that R-12 compatible stuff. How much does it usually cost to do a good r134a conversion?

 

[Kestas]

A good, long-lasting conversion at a minimum should include:

- Fix the leak.
- Undo all connections, replace all o-rings.
- Flush out lines, condenser, and evaporator to remove old lubricant. Use mineral spirits followed by either lacquer thinner, alcohol, or brake cleaner.
- Drain all old lubricant from compressor.
- Replace receiver/dryer/accumulator.
- Fill with specified amount of lubricant, R-134 compatible.
- Pull vacuum.
- Charge with R-134, roughly 80% of specified R-12 charge, using vent temps and manifold gauge pressures as a guide to the exact amount.

It's really not a whole lot of work to do it right. The toughest part for most DIYers is finding some way to pull the vacuum, buying an a/c manifold gauge set, and finding a source of shop air for the flush.

Once you have the tools, the cost is mainly buying new parts to repair the original leak. Refrigerant, lubricant, and o-rings should run about $50. The receiver/dryer is about $35-70. Try acsource.net for parts.

 

[bigwillie]

thanks for all of the info kestas my uncle who is a mechanic is going to help convert it to R-134a and he already has all of the gauges and equipment, I just wanted to know what to buy so maybe I could have the parts ready for when he comes to help me with it, thanks a lot.

 

[Chris142]

quote:

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Originally posted by bigwillie:
How much does it usually cost to do a good r134a conversion?

---

I get $250-$300 to retrofit a car/truck. This includes the new Accumulater/drier, all O-rings, Orface tube, vacuum, retrofit adapters and charge.

Any other problems such as a leaky hose, compressor etc will be more.

 

[bigwillie]

I just heard from a few people on one of the a/c forums and my bronco ii forum also that r134a will be banned by 2007 or 2008. I'm still going to convert it over I think but I don't understand why they are banning it. I thought it didn't omit CFCs and didn't cause global warming like freon did.

 

[Chris142]

They are going to stop making 134a because it does contribute to global warming. Not nearly as bad as R-12 does.

I heard 2011 was the date set.

 

[dkcase]

quote:

---

They are going to stop making 134a because it does contribute to global warming. Not nearly as bad as R-12 does.

I heard 2011 was the date set.

---

So R-12 was "ozone depletion." Now R134a is "global warming."

 

[tdi-rick]

sure 'they' aren't getting confused with R22 used in domestic/commercial/industrial air conditioning ??

It is being phased out, currently being replaced with R410A.
I think R134A will be with us for a while yet.

FWIW, there is an excellent drop in available here in Oz marketed by Origin Energy called 34M. It is 90% R134A, and works brilliantly in commercial refrigeration, including low side float systems such as beer systems, as well as auto AC, where I've used it in place of R134A in things such as tractor cab AC.

 

[mechtech]

The lubricant oil is different between the two systems. You have to have ALL of the old stuff out. That means a new receiver/dryer, at least.