R134a conversion
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Newbie
Joined: Jun 2002
Posts: 2
Likes: 0
From: Alexandria VA
1986 300E
R134a conversion
Anyone done a R134a A/C conversion? My '86 300E is starting to blow luke-cool air, which I suspect means that I've got a slowly evacuating system. Since R-12 is now an illicit substance, I thought to convert to R-134a. My brother-in-law tells me that it's a simple matter of totally evacuating the system and replacing a couple of fittings, all for ~ $30. Not that I don't believe him, but it sounds suspiciously easy, and if that were so, wouldn't everyone have converted by now?
Any info would be appreciated.
Any info would be appreciated.
Almost a Member!
Joined: Dec 2001
Posts: 30
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From: TX
95 E 320 Cab
R134 conversion
Actually had this done to my old '88 model 735i. Had it done at a Porsche independent shop for around $200. I don't know what all the procedures entail, but I think the new refrigerant runs at higher pressures than R12. If you are loosing coolant, you may want to track that down first. A coolant leak is a colant leak, and you can imagine it would be worse at higher pressures. Although, 134 is a lot cheaper to **** away than R-12.
Almost a Member!
Joined: Jun 2002
Posts: 48
Likes: 0
From: Houston
1995 Oldsmobile Cutlass Ciera
Re: R134a conversion
Originally posted by jwfisher3
Anyone done a R134a A/C conversion? My '86 300E is starting to blow luke-cool air, which I suspect means that I've got a slowly evacuating system. Since R-12 is now an illicit substance, I thought to convert to R-134a. My brother-in-law tells me that it's a simple matter of totally evacuating the system and replacing a couple of fittings, all for ~ $30. Not that I don't believe him, but it sounds suspiciously easy, and if that were so, wouldn't everyone have converted by now?
Any info would be appreciated.
Anyone done a R134a A/C conversion? My '86 300E is starting to blow luke-cool air, which I suspect means that I've got a slowly evacuating system. Since R-12 is now an illicit substance, I thought to convert to R-134a. My brother-in-law tells me that it's a simple matter of totally evacuating the system and replacing a couple of fittings, all for ~ $30. Not that I don't believe him, but it sounds suspiciously easy, and if that were so, wouldn't everyone have converted by now?
Any info would be appreciated.
Newbie
Joined: Jul 2002
Posts: 1
Likes: 0
From: Union, NJ
1992 300E Auto
134a conversion
I had a conversion done today on my 92 300E. The mechanic removed the dryer i think it is called, sucked the r-12 out, put oil and 134a in. Reason i finally did the conversion was that i have a slow leak and this year i couldn't find a place with r-12. They tell me (part shops) that it would be 95.00 a lb. if they had it. So far so good works well and now at least if it leaks, i can get more.
BTW with the dryer it ran 225.00.
BTW with the dryer it ran 225.00.
Member
Joined: Feb 2002
Posts: 136
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From: Massachusetts
Mercedes-Benz 300D TURBO 1987
Converting to 134a
To convert from R12 requires a new receiver/drier (not expensive) and a competent tech who knows about the incompatability of these two refrigerants. Your Nippondenso compressor contains mineral oil which you cannot completely remove by evacuating the system. O-rings must be changed and a thorough cleaning of your system must be done to prevent breakdown because of incompatibility. The truth is that R12 is vastly superior in terms of cooling off a hot interior faster and producing colder temperature. Now that scientists are certain that the increased temperature of the sun is the cause of the hole in the ozone layer and not R12 we will all wonder about R134. Millions of wildebeast in Africa emit huge amounts of methane gas daily, so the amount of R12 is paltry by comparison. No new R12 is being manufactured but there are huge quantites of it around. Talk to a Mercedes dealer about what should be done to correctly convert, then you'll know if you have it done elsewhere. P.
Newbie
Joined: Jun 2002
Posts: 14
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From: Houston, tx
1992 300E
A/C Conversion
Changed out my R12 last year to R134 on my 1992 300E and it cost me a total of $60 bucks. A new fitting adapter, 3 cans of freon, evacuating system, a little r134 freon o ring oil. No new drier. If you don't live in Houston, Tx. where it gets to almost a 100 deg. then go the cheaper way. The cooling is okay during the day and good at night. I kinda want to go back to R12 as i remember it was colder. Also, some people told me that 300E's 86-90 compressors were not very efficient with R134 and longterm not good. Check mercedesshop.com and do the search for a/c con. as there is a bunch of people who did theirs.
Sonny,
Sonny,
Last edited by rexdog29; Jul 24, 2002 at 06:26 AM.
Junior Member
Joined: Jun 2010
Posts: 17
Likes: 1
From: New Braunfels, Texas
85 - w201.024 / 89 - w126.035
It's so cold in that car sitting in downtown traffic at 4PM that I must turn it down. I should take a picture of an inside thermometer next to the outside temp gauge and post it
Last edited by scottx; Jun 23, 2010 at 12:31 AM.
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Junior Member
Joined: Jun 2010
Posts: 17
Likes: 1
From: New Braunfels, Texas
85 - w201.024 / 89 - w126.035
It was completely empty and we vacuumed it down. It's setup perfect now. This was all done by me and a good friend who does a/c work for a living.
We recharged it this morning just to vacuum it down and redo it. It wasn't leaking or anything. Work's so good.
We recharged it this morning just to vacuum it down and redo it. It wasn't leaking or anything. Work's so good.
Last edited by scottx; Jun 23, 2010 at 11:46 AM.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,213
Likes: 5
From: Kirkland, WA
500E Signal Rot
I had a conversion done today on my 92 300E. The mechanic removed the dryer i think it is called, sucked the r-12 out, put oil and 134a in. Reason i finally did the conversion was that i have a slow leak and this year i couldn't find a place with r-12. They tell me (part shops) that it would be 95.00 a lb. if they had it. So far so good works well and now at least if it leaks, i can get more.
BTW with the dryer it ran 225.00.
BTW with the dryer it ran 225.00.
Newbie
Joined: Apr 2024
Posts: 1
Likes: 0
1991 Mercedes 300ce
Can you help?
Changed out my R12 last year to R134 on my 1992 300E and it cost me a total of $60 bucks. A new fitting adapter, 3 cans of freon, evacuating system, a little r134 freon o ring oil. No new drier. If you don't live in Houston, Tx. where it gets to almost a 100 deg. then go the cheaper way. The cooling is okay during the day and good at night. I kinda want to go back to R12 as i remember it was colder. Also, some people told me that 300E's 86-90 compressors were not very efficient with R134 and longterm not good. Check mercedesshop.com and do the search for a/c con. as there is a bunch of people who did theirs.
Sonny,
Sonny,
