R134 recharge questions and recovery equipment - PeachParts Mercedes-Benz Forum

rhodes2010 · #1 02-02-2006, 02:50 PM

I studied this thread from June 2005 on Refrigerants.
It mentions R134 R12 and "Freeze 12".

Ac Cold At Last!! 83 Sd

I have a 1980 300D that has an empty AC system. (It worked fine when last
used - had it recovered before pulling engine).

Putting in a new Receiver/Drier and going to recharge it.
I have converted other R12's to R134 and have never had a problem.
Whatever loss there has been in cooling, it has been acceptable.
I am no AC expert, just a DIY.

1. Usually I do not use gauges, but this time I thought I would
go ahead and purchase a gauge set - most of you use gauges ?
Anybody got numbers for hi and lo pressure ?
2. I will not ask about Freeze 12 - that discussion has been covered
in earlier thread - But, LarryBible, what about "Enviro-Safe".
My gut experience has been that anything New,Improved,Works Like,
better than, is a bunch of hooey (not worth it, hype). So I am
inclined to completely dismiss it and stick with approved R134.
Thoughts ?

3. I see used R12 recovery equipment for under $100. I certainly
cannot afford R134 recovery equipment. But what a shame to
see this stuff go to waste. Is there any way to get approval for
use in R134 ? It would be great to have a R134 recovery system
in my home tool shed.
I thought you were not supposed to mix R12/R134 recovery,
but this listing is for a Dual Purpose R12/R134 recovery machine.

http://cgi.ebay.com/ebaymotors/SKYE-MULTI-REFRIGERANT-A-C-RECOVERY-MACHINE-R134A-R12_W0QQcmdZViewItemQQcategoryZ63700QQitemZ4572806843QQrdZ1QQsspagenameZWD1V

Some new loophole/regulation ?

dannym · #2 02-02-2006, 03:01 PM

That unit on e-bay is approved for "EP10M R12, 22, 500, 502 &134a." Every time you switch refrigerants you have to change the filter and tank. This is nothing unusual all units are like this.

Quote:

Putting in a new Receiver/Drier and going to recharge it.
I have converted other R12's to R134 and have never had a problem.
Whatever loss there has been in cooling, it has been acceptable.
I am no AC expert, just a DIY.

You should seriously consider flushing it first.

Quote:

1. Usually I do not use gauges, but this time I thought I would
go ahead and purchase a gauge set - most of you use gauges ?
Anybody got numbers for hi and lo pressure ?

If you want to do it right get gauges.
Pressures all depend on ambient temperature.
http://www.ackits.com/index.cfm?fuseaction=Chart
http://www.ackits.com/
Another good website to check:
http://www.airconditioning.com/start.htm
I would also recommend going to your nearest auto parts store and buying an automotive Air Conditioning guide.

Quote:

2. I will not ask about Freeze 12 - that discussion has been covered
in earlier thread - But, LarryBible, what about "Enviro-Safe".
My gut experience has been that anything New,Improved,Works Like,
better than, is a bunch of hooey (not worth it, hype). So I am
inclined to completely dismiss it and stick with approved R134.
Thoughts ?

If you know about Freeze-12 then you know about "Enviro-safe". Do you really have to ask?

danny

rhodes2010 · #3 02-02-2006, 03:07 PM

Chuckle. Okay - That is what I thought.

dannym · #4 02-02-2006, 03:22 PM

Quote:

Originally Posted by rhodes2010

Chuckle. Okay - That is what I thought.

No problem.
But really do it right the first time.
Flush it out good. You can buy a flush kit fairly cheap. http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=AR4201
Or you can use this and compressed air. http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=AR4202
Or you can even use paint thinner/mineral spirits and compressed air.

If you flush your going to have to remove the expansion valve. Don't even think about doing this without metric flare wrenches.
http://buy1.snapon.com/catalog/item.asp?item_ID=99&group_ID=570
You don't have to get Snap-On but you can see the difference between these and regular open end wrenches.

Also replace the TX valve AFIK they are around $20.

Get some Nylog for AC connections.
http://www.ackits.com/index.cfm?fuseaction=Nylog
http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=RT200R

Don't forget to replace your O-rings:
http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=21-24708

danny

#5 02-02-2006, 04:33 PM

Since you are this deep into it, you should follow dannys advice and flush everything thoroughly and replace the r/d.

R12 has gone down DRASTICALLY in price, so there is just no reason WHATSOEVER for not using it. I bought some last year for less than $15 per pound while 134 was going up to almost $10 per pound. It very well could be that this year the prices equalize.

Envirosafe is another of the ZILLIONS of replacement or alternative refrigerants. I call them JUNK refrigerants. All alternative or replacement refrigerants fall into one of two categories; flammable or blend. The disadvantage to a flammable refrigerant is obvious. The disadvantage to a blend is that the components leak at different rates. In the event of a leak, the only way to get it right again is to recover ALL remaining refrigerant, evacuate and recharge. Recovery requires a recovery system dedicated to that specific refrigerant.

People selling junk refrigerants are constantly saying how superior their product is to whatever refrigerant they are selling against. If you want to believe them then it is totally up to you. When R12 was going for $50 per pound or more, there was lots of desire to believe them. With R12 prices now nearly the same as most anything else there's no reason to buy their snake oil.

In addition to the above reasons for not buying junk refrigerants is that by law you are supposed to have the CORRECT fittings for the alternative refrigerant of your choice. The cost of the proper fittings will cost more than the difference in the junk refrigerant and R12.

In addition to that you are not supposed to recover different refrigerants in the same vessel. If you do, that vessel is to be disposed of and disposal is expensive, not to mention the loss of whatever R12 or other legitimate refrigerant that happens to be in the container.

With Spring coming on, I shutter to think how many times I will have to explain this all over again.

Please do yourself a favor and put your system back together properly with R12. You may have had good service from other converted systems but the 123 MB has very little if any reserve condensor capacity. Unless you are in a very cool climate you will not get the cooling performance that you would get with R12.

Additionally, statistics show that converted systems last an average of two years before major repairs are required. It just makes sense to stay with what is tried and true.

Also, it is always VERY helpful to us here when posters have their location in their profile so that we know what climate we are discussing.

You might try reading the "Get the Most from your Post" thread above.

Good luck,

Hit Man X · #6 02-02-2006, 05:17 PM

Just stick with R12, the system capacity isn't enough to take a conversion to 134A easily. It's cheap, easy to obtain when licensed, etc.

#7 02-02-2006, 05:29 PM

I have one W123 with R12 and one with 134a. The R12 is colder, but the 134a works fine unless the outside temperatures are VERY high. The 134a is still a little cheaper and easier to get. IMHO, there's not much of a reason to convert in either direction. If the cost was the same, I would probably go with R12.

Hit Man X · #8 02-02-2006, 05:36 PM

Exactly.

See I live in Texas, it's similar to being in Hell during the summer due to the heat so 134A will not suffice in the MB's unless they have the newer condensor with dual aux fans. My F150 was converted to 134A a while back but since it needs a new compressor I may as well revert back to R12 here.

I was hardcore last summer and drove the SD without A/C.

Not this time, I have to pick up a single small hose, fan switch, and pressure switch, still then a case of R12... then the A/C shall work again. Probably the first time since the mid 1990s.

The EPA license is a object to have in your hands.

imdavid28 · #9 02-02-2006, 05:42 PM

Quote:

Originally Posted by LarryBible

When R12 was going for $50 per pound or more, there was lots of desire to believe them. With R12 prices now nearly the same as most anything else there's no reason to buy their snake oil.

Why did R12 drop in price? Did they start making it again?

#10 02-02-2006, 06:08 PM

The reason for the fall in R12 price is simple supply and demand. The cars requiring R12 have not been made for about 12 years now so they are at an age where they are hitting the junk yards in record numbers.

So, the decreasing demand has the same pricing effect as if there was an increasing supply.

Have a great day,

Hit Man X · #11 02-02-2006, 06:49 PM

Yup, there's an excess of it around and I recall production didn't stop until around 2001 in foreign countries.