Need to know if the condenser oil should be or any equip be replaced to recharge to the 134?Other then discharge a good running system that is out of R12 Help please.
R12 and R134a are not directly compatable. Like all "safer" alternatives R134a isn't as good as the original it replaces(Light beer and Diet Coke are other examples). Systems that run on 134a have a compressor that is 12-18% larger because of reduced thermal efficiency, but since you probably don't want a class in the thermodynamic qualities of fluids at varing temps and pressures here's the dope:
If you have in fact repaired the leak that caused the R12 to get away in the first place you should be able to use 134a. You will have to evacuate the system and drain all the oil. From what I understand the fittings on the 134a systems may not mate up to an R12 (on purpose so you can't mix them), so you may have to replace the drier with a 134a compatable one. After you do what you have to and refill with 134a and 134a oil the system should work, just not quite as well as it did before.
I asked an air cond. mech about changing over from R12 in an older F150 and was told the R12 hoses are too porous for R134A. I was told the compressor would handle the job but all hoses had to be changed. The 134a hoses have an extra layer to prevent leakage. Just my 2 cents.
I don't doubt that the hoses differ from R12 to 134a. I was reading a few articles on the web that people had posted regarding their personal experience in doing a "shade-tree" change. Apparently you can get away with the same hoses (for awhile at least) because the R12 and its oil have coated the interior sufaces and "protect" them. Of course Thad and his AC friend are right, if you want to do it right you should replace the refrigerant, oil, hoses, drier, and possibly the metering valve. If you want to do it cheap; oil and 134a (crossed fingers are optional)
Ok so I do want to go cheap.But the old saying is you get what you pay for .The near by Wall Mart has the fittings to go right over the old ones .And covers old and new that are r12.And the cost is nine bucks.What I didn't know was if the oil was the same and where to put it.They sell 134a for 5 bucks a can and takes 3 of them.Just wanted input from anyone who has done this.Think about it 50.00 x 2.4 or 3x 5 .Anyone ?
I hate to be a shill for another site, but since you have an older model truck this question is better answered by folks who have actually done it. I am inserting a link (hope this works) to an older model Ford vehicle site where this topic is more common. I hate to send you elsewhere, but here goes....
the R-12 hose is porous ? I do not think so . They can not be , remember these hoses are made for high pressure . However the 134a does operate at a higher pressure than the R-12 . You can use the same hoses , but you will need to flush them completely . If it is an older model , check into the cost of new hoses , if it is under $ 75.00 for the pair ,it might be a good idea to change them if they are over 10 years old . It would really suck doing the job twice and having to pay a shop to charge it twice in order to save a dollar on a hose .
I just put on the kit for the change in fittings and dumped in the 134 and it works.. my bro in law is a mechanic and he has had guys do this without a problem for a couple of years now.. so I did it and it runs fine and cools good too.. this was a 93 F150 5.0L.
What you got to lose? if if messes up you were gonna change the hoses and all anyway.. right? besides winters coming and you wont be in a rush if it doesnt work.. just my thoughts
Dana
I am testing this out on a ford that I dont care about and it has work just fine.The kit cost 34.00 US and am very satisfied.The temp was 64 F out of center When it was just cool.Had nothing to loose.Thanks to all input.This has been very useful . Best linkhttp://www.ford-trucks.com/dcforum/DCForumID110/241.html]Best link[/url]
Hi,
I can be wrong here... but you cannot mix R12 and 134a - it can break your compressor. You have to dump R12 first and re-fill the system with 134a. That's all you need. At least that's what I read here:
Originally posted by AB Hi,
I can be wrong here... but you cannot mix R12 and 134a - it can break your compressor. You have to dump R12 first and re-fill the system with 134a. That's all you need. At least that's what I read here:
Have tested this on my 93 ford and took the car to an A/C service
station and thay were glad to take the R12.My system was empty and was refilled with A/C oil and 134a and has been fine.All for about 35 bucks.I am very happy for now.
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R12 vs 134
R12 to 134a Retrofit
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