converting 134A - Page 2 - PeachParts Mercedes-Benz Forum

ah-kay · #16 05-19-2011, 01:32 PM

Quote:

Originally Posted by sjh

I know one tenth of what the senior technical know on this matter and have less then 1% of their experience. But I will tell you what happened to when I graduated from college.

I could not afford the cost of repairing my R12 system. I had just graduated, terrible job market, etc.

This is what I did. It was not morally appropriate but I'm sharing it because of the technical consequences.

I bought the $15 kit, vented my R12 to atmosphere, did nothing else to prepare the system and filled it with one can of 134a oil and 2 or 3 cans of 134a.

For the next 15 years I would add between one to two cans a year as the system leaked. When the car was sold no money had been spent for 15 years to repair/improve the AC, it still worked well, including a year in Dallas and gave no indication that it would not continue to do so.

I neither attempt to justify my intentional polluting of the atmosphere nor in ANY way suggest that anyone do this.

I am saying this extremely crude conversion worked for 15 years.

I would not repeat my actions today. Some of us are slower at becoming adults then others.

+1.

A good R134a conversion can be had for under $100. If all the R12 is lost then nothing is vented to the atmosphere. I normally changing out the Rec/Drier, add 8 oz of ester oil and 2-3 can of R134a. It works every time.

Beastie · #17 05-19-2011, 01:32 PM

Quote:

Originally Posted by leathermang

WHAT BS !!!!

You start out in first post with ' Fully Functioning System " question ....
then say it is not operational.....

Leathermang, NO BS!, It was working last summer and then nothing this spring.
I found a refrigerant loss due I suspect to a loose shcraeder valve or one that was not fully threaded or seated thus the total loss of pressure. True there could be other issues however due to the known system operation before the winter it is reasonable to expect no changes except the obvious loss of gas.
Since I may be back in a 9-5 job soon and wearing a suit again. I take the a/c system as a necessity to keep my 6'4" 305 lb body cool and comfy while wearing my monkey suit between job sites. I do agree maybe I could have worded and titled my thread differently though.
Alan

leathermang · #18 05-19-2011, 01:39 PM

Quote:

Originally Posted by Beastie

On a fully operational factory a/c ( R12) what is done when converting to 134 ?

You set it up to where no one in their right mind would simply answer the question based on what you said..... because it makes no sense to change a working R12 system... just as Vstech and I approached the situation from.
Then say you knew there was going to be an ' onslaught ' of critical reaction.
It was only the way you forecast because you did a Bait and Switch.

ah-kay · #19 05-19-2011, 01:52 PM

It is too harsh to call the OP names, or bait and switch. It is quite normal to have a working A/C last year and nothing work now. Just like any car could start yesterday but now is dead. What is new.

I suspect all the R12 is lost and the pressure switch is off. It is natural for R12 to leak slowly and it probably just goes below the threshold. I would do this tests before the next move.

1) Press down the the shrader valve momentarily and see whether you hear a hissing sound. If it does then you still have R12, albeit a bit low. The purist would use the measure gauges but this test will do.

2) Measure the pressure switch across the Rec/Drier ( lower one ) using an ohmmeter and see whether it is closed. If it is closed then you have enough pressure and the no-op problem is elsewhere.

3) If it is open then the likelihood is no R12. Recharge with R12 and forget about the conversion. Or jump the switch and turn on A/C for a short while to see whether the compressor runs. If it does, then it further confirm that it is lack of R12.

Good luck.

Beastie · #20 05-19-2011, 01:54 PM

Leathermang, Take a deep breath and relax. there was and is no bait and switch what the heck would be my benefit. My comment regarding an onslaught is because if you have almost any thread discussing a car originally built with r12 you get an onslaught of response expounding on the virtues. Then you get a ton of " I added purified eskimo urine and can get my interior temp down to 30 degrees". I was trying to avoid that garbage discussion. My question regarding conversion was to see what would have and or should have been replaced for a proper conversion if as I went through paperwork it would have shown it already having been done. Fortunately VS tech was able to tell what to look at to confirm wheter or not it had been done besides just a sticker which as we all know can be faked and or come off on their own. Sorry to get you dander up.
If this took you away from something important I apologize.

Beastie · #21 05-19-2011, 01:59 PM

ah-kay, thanks for the defense. I may have just caught him at a bad moment and it just took to him the wrong way as written. That said as I posted VS tech told me what to look for and I was able to confirm that for better or worse it has been converted. It has the internally threaded fill port and the cap is red. Now to do the checks as outlined here and also replace the receiver dryer while the system is fully discharged and before refilling.
And again thanks to all for the input.
Alan