Converting to 134a

[Greenleaf]

This is the story... ... ... ... ...



They told me they would simply recharge it with 134. End of story.



I did ask questions.



I did have to upgrade the condenser. And was told to replace the dryer too. My condenser was busted. That's why I had to replace it/recharge it with something.



No. It won't cool as well as 12. It's environmentally friendly.



It's prone to leakage. But I can top it off myself, and it's cheap!



Some told me to keep the 12. Some told me to convert the thing.



I'm a convert now. Not to be confused w/a convict.



What kind of luck have you all had w/134a conversions. Was it a wise choice???????



A friend of mine, who lives in IN performs A/C work all the time. Said he only swaps out the dryer. Works well.



Some shops will tell you that you need to replace everything but the evaporator and compressor.









-S

 

[ARedetzke]

Buddy of mine who is certified for A/C work told me you can just fill it with 134A without changing anything. I guess I'm going to be giving that a shot here soon, since I'm too broke to pay for R-12, or a dryer or anything else (the wife wants furniture in a bad way). I'll let you know how it turns out.

AJ

 

[Grey Wolf]

This is what the engineers use at my old place of employment, it's a direct drop in for R-12. The E. Chief has been using it in his pick up for a few years with great results and my son has good luck with it too



http://www.icorinternational.com/hotshot/stationary.html

 

[CDegner]

A buddy of mien that has been doing A/C work for 30 years says that if you just replace with 134a, the system will not work as efficiently as it did with 12 or as well as it could with 134a.



Anytime you have the system open you should replace the dryer. That just makes common sense to me. Even when I had a central air unit with 22, if I opened up the system, new filters, both high side and low side, went in.



Carl

 

[JKurley]

My mechanic evacuated the old R12 last summer, and installed R134, heavy on the luricating oil. All through the desert southwest, it kept me cool, but not AS cool as R12, something I've noticed in several other cars.



If your system is empty, I dont think you need a new dryer, or any other parts replacement, except the fittings, but make sure that at least two of the cans of R134 include lubricating oil.

 

[ARedetzke]

Yeah I was told that it wasn't as efficient too, but on a shoestring budget, I'm not looking to hang meat in there. I'll take any cooling ability at all over what I have now, which is nothing.

AJ

 

[bvanetten]

condenser condenser condenser

You can never have to much condenser. It's the counterpart to your evap. The evap removes the heat from your cab and the condenser removes the heat from your system. A good rule of thumb is twice as much condenser as evaporator. Does everyone remember the first couple of years that car manufactures started using 134a? Remember how bad the cooling preformance was? The condensers were sized for r12 systems... Look at the condenser in a new Dodge cummins, it has almost the same footprint as the intercooler! If you want to have a system that was originally designed for r12 work as good or better with 134a increase the size of your condenser by at least 50% and change out the expansion valve or oriface tube to work within 134a parameters. Anything less is just pushing a rope. We could talk about refridgerant properties and molecule size and blah blah blah... . but in the end you will just want to do the above. It will lower your cab temps and your frustration level at the same time!

 

[bgilbert]

Yep was always told, anytime u open the system new dryer. I've replaced my dryer twice $40 Napa. Evaporator Napa was $140. Evpansion valve can't remember price. Reman compressor big money, got it when I bought the truck. I've replaced everything but the lines and the condensor. If you want AC in one of these old trucks, ya pretty much have to update everything. I had decent AC last summer, but now my charge must have escaped, cause no AC at the moment. Looks like I'm gonna have to foot the bill on the big money condensor and lines if I want the 134 to be as efficient as can be. And yes we all know, its not as cold as 12. Bill

 

[bvanetten]

It can be...

It can be as cold as r12 if done right. A few years back I put ac in a 66 mustang I had. Set it up with 134a and in the middle of a Phoenix summer it would freeze you out. I'm talkin 38 to 40 degree vent temps on a 105 degree day.

 

[MidwestMotorman]

You may have to adjust the amount of 134 you put in. You may need more pounds than with r12. Always consult with AC/heating experts though so you don't damage your system.

 

[dan brooks]

I had my F150 converted to R134 and it worked great. The compressor was shot when I bought it, so a remanufactured one was installed, along with a new dryer and orfice tube. Can't compare between the R12 and R134 in the same vehicle but I was happy with how well it worked.



Like everything else, there is a right and wrong way to do things, and you get what you pay for. Talk to a reputable AC shop that does a lot of conversions to find out what really needs to be changed - it could save you money in the long run.

 

[RobbieH]

A/C is not working on a friend's 1st Gen. He's thinking about converting to 134. Needs a new compressor, drier and expansion block. Any ideas on what a shops typically charge to have this done? Thanks.

 

[Greenleaf]

About $35-40 dollars/hour..... plus parts.

Or, use the TDR. Armed w/said info... ... ..... DIY



-S

 

[Greenleaf]

I'm seeing 57° discharge temps. typically. However, I did register 47° 'other day. I had to shut her down. Too chilly for the wife. I have tested the wife's car at 42° It was sold new w/134a



My low side pressure is 26 lbs for each vehicle. I had a reputable shop charge the 1st gen after I performed the conversion. They charged her to 26lbs low side, same as I have been topping off the wife's car. They "charged" me 85. 00 to pull the vac and test it after my findings to "double check" for leaks and charged her up for me. I will have to top if off myself as pressure drops in time.

You have to monitor the high side a bit and I couldn't do that with my old r12 manifold set. They say it's good. (Low air flow will effect this)



-S

 

[jimk]

cold air

I have done a few conversions on some 380 b wheel dozes. They use sandon compressors, we went to freeze12, it is a blend. Now you have to be careful when you charge the system. I have some friends who have used it in there trucks also. You can mount a electric fan in front on the condenser to aid heat removal at slow speed. On a truck, or car.

The expansion valve can be tuned to change the superheat. I think is what was told to me. The problem is oil flow to the compressor, some oils don't flow good. Compressor problems can result. I like to clean the system as good as I can to start with. Ever had a dryer receive come apart in the system? That will really chap you. Things have probably changed in the last couple of years. good luck Jim