The R12 in my mk1 diesel all came out, and because it is no longer made what is a direct replacement for it? i know r134 exists but i've read that requires some type of conversion? is there any product that i can just recharge the system with with out having to put in a conversion kit? and no. i will not take out my ac for 2 more hp, its hot as hell in florida and the diesel L is already slow as ****.
ac in diesel L r12 direct replacement?
Shelboman
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The R12 in my mk1 diesel all came out, and because it is no longer made what is a direct replacement for it? i know r134 exists but i've read that requires some type of conversion? is there any product that i can just recharge the system with with out having to put in a conversion kit? and no. i will not take out my ac for 2 more hp, its hot as hell in florida and the diesel L is already slow as ****.
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my neighbor is in hvac and charged my car with stuff called hot shot, it worked great until one of the ac hoses blew.
The r134a conversion is usually just the fittings that go on the high and low pressure ports. They screw on and done. Then you refill it with the r134a stuff.
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since it's so much less in demand one can actually lay hands on R12 pretty easily these days, I've bought it off ebay in the not too distant past.
Little bit of a can o worms but it's possible. having run 134 and some r12 replacements both in these things over the years that would be
my first choice by far. especially in FL. You just can't half-ass it, system needs to be tight and in good order and it'll last another decade
or more with 12.
Little bit of a can o worms but it's possible. having run 134 and some r12 replacements both in these things over the years that would be
my first choice by far. especially in FL. You just can't half-ass it, system needs to be tight and in good order and it'll last another decade
or more with 12.
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Alot of good points up above. Best bet is to crack open the system in a low point and flush the system the best you can. Then buy the R134 adapters which are super easy to install and then have it evacuated and recharged by a professional. The amount of R134 vs. the amount of R12 you put in is quite a bit different so the factory specs are invalid on how many ounces to put in. A good AC tech will know what kind of numbers are good on the Hi/Lo gauges. Make sure they know before charging the system that you flushed it and need the oil replaced (injected) also (it's all part of charging the system). R12 oils are different that R134 oils and if their mixed it's not good. 
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Stick with r12 if you can.
134a systems were designed to hold more refrigerant, because it's not as efficient. Other than the oil, fittings and o-rings, it would work, but you also may need to upgrade the hoses to barrier hose. The 134a molecule is smaller than r12 and can bleed through the rubber.
-Todd
134a systems were designed to hold more refrigerant, because it's not as efficient. Other than the oil, fittings and o-rings, it would work, but you also may need to upgrade the hoses to barrier hose. The 134a molecule is smaller than r12 and can bleed through the rubber.
-Todd
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I'm running a similar product, in my B4, but you can't run it straight. I had pressure issues where it tripped the safety valve, causing a loss of refrigerant and oil. You need to figure out the recommended equivalent weights, then only use about 30%. Running higher mixtures will result in higher head pressures, colder discharge air, but the possibility of needing to add a cold cut off switch to keep the evaporator coil from freezing.
Some/most of these gasses cannot be charged under vacuum and must be charged as a liquid.
I've also run propane, computer duster, etc., as experimental refrigerants.
-Todd
Some/most of these gasses cannot be charged under vacuum and must be charged as a liquid.
I've also run propane, computer duster, etc., as experimental refrigerants.
-Todd
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duracool and freeze12 and such been around for a long time, they are usually blends of 134 and some other stuff to try and make it more efficient.
My experience with them is that in a Caddy, with a Rabbit sized HVAC system and as long as the humidity isn't crazy high they are "ok".
Anything beyond that I found the performance lacking a lot compared to 12.
My experience with them is that in a Caddy, with a Rabbit sized HVAC system and as long as the humidity isn't crazy high they are "ok".
Anything beyond that I found the performance lacking a lot compared to 12.
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I am not an HVAC guy so I cant tell you what is the best route. I can tell you with my experience with my 86 cabriolet and r134a. When I bought the car from my mechanic he adapted the system by just buying the high and low connections (probably a walmart kit) and then charging the system. For my first summer with it, it worked great then I lost the A/C towards the end of summer. At the end of summer the old r12 ac compressor seized up and I had to replace it. I am assuming the seals went in the compressor because I had no Freon in the lines. Luck for me I had a r134a compressor that came with a diesel engine I had bought for my caddy. I installed it because it was something at the time to run the alt till I got through winter. When summer came the next time I decided to dive in to fix the ac. I bought the r134a o rings to seal everything easily accessible in the engine compartment ( still wish I would have did the interior to.) Grabbed a can of pag oil to fill in the system and a couple cans of r134a with the cheap guage. charge the system with pag oil and then with Freon and to my surprise it worked. It works great in honesty even with a convertible top. In the three summers and working on a fourth with the system charged I only had to charge it up once again and that was about 1.5 years ago. Still holding strong. That is with r12 condenser, evap, hoses, etc. Only thing that is 134a rated is the compressor and that might be the golden egg. Is the system fast to cool at first no. Honestly I have to be above 35mph to get it initially cooled down and then I am good for in town driving but for a almost 30 year old system it works great. Are there things I wish I would have did different yes like I did not change out the drier ( I honestly didn't think the system would hold a charge), I wish I would have had the system vacuumed and properly filled but again did not think it would hold a charge.
Bottom line does r134a work yes it does. Going 4 summers strong with it and that is not even a professional job. It may never be as good as r12 but it beats the hell out of nothing at all.
Although looking forward to adding ac to my diesel truck and the eventual failure of the cabriolet system. I will probably go a more custom route with more easily gotten parts and all hoses and fittings rated for 134a and a professional vacuum and fill. Then it would act like a new car with instant cool down, town driving or not.
Bottom line does r134a work yes it does. Going 4 summers strong with it and that is not even a professional job. It may never be as good as r12 but it beats the hell out of nothing at all.
Although looking forward to adding ac to my diesel truck and the eventual failure of the cabriolet system. I will probably go a more custom route with more easily gotten parts and all hoses and fittings rated for 134a and a professional vacuum and fill. Then it would act like a new car with instant cool down, town driving or not.
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Higher efficiency condenser goes a long way toward making r134 work.
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We converted our mk1 Jetta to r134a (everything, compressor, condensor, hoses, etc) and it works really well. No complaints for sure (other than the HP zap in our diesel...at least its got a turbo :laugh
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Typically 134 takes a higher charge and pressure to function very well, it's hard on compressors not designed for it and it loads the motor more. You can feel the AC on in an r12 NA diesel, but it's like throwing out an anchor with 134. Not doing the marginal V belt system any favors too. Work with what you got though I guess.
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lol. I hear you on that. My mechanic had one (na) he wired a switch to the compressor so when he hit an incline of any significance he shut the compressor down so that he still have cool air and once he top the hill he kick the compressor back on. Its a price to pay to be cool in a diesel but I am definitely willing to pay it.We converted our mk1 Jetta to r134a (everything, compressor, condensor, hoses, etc) and it works really well. No complaints for sure (other than the HP zap in our diesel...at least its got a turbo :laugh
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I forget if it was vw but one of the old diesels I owned had a wot ac cutout switch factory.
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I used something called r12a sold by duracool. It works pretty well and was effectively a drop in replacement. PM me if you have questions about it; I've done some research regarding it and also spoke with the owner of the company.
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