Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Feb 2005
Posts: 34
Refrigerant substitutes

Just want to hear any experiences any of you have had with getting the AC to work with a different refrigerant. Autozone is selling a "conversion kit" which is simply some fittings, and some oil to add to the system, and claims that after that I can use the 134 type refrigerant. Any other suggestions?

__________________
87 944S
73 Datsun 240Z
Old 06-25-2006, 07:41 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
Join Date: Aug 2003
Location: Texas
Posts: 196
According to www.griffiths.com heres what to do to make a conversion to 134. Its not quiet as simple as the auto part stores claim. For one you have to remove all the old oil from the system which means removing your compressor. You can go to Griffiths web site and read more about the subject. Basicly your system was designed for r-12 so stick with r-12. If you do make the 134 conversion you need to install a bigger condenser for the 134.

1. Unplug the a/c's clutch wire
2. Loosen the a/c belt
3. Disconnect the two hose lines to the compressor, protect the ends from getting dirty.
4. Remove the compressor.
5. Remove the old mineral oil from the compressor by turning it upside down, side to side, and turn the front hub on the clutch assembly.
6. Recharge the compressor with a/c ester oil and a "tracer dye". Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car.
7. Put the compressor back on the car.
8. Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil.
9. Reattach and tighten the a/c belt.
10. Plug in the a/c clutch wire.
11. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores.
12. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings.
13. If your car does not have a high pressure cut-out switch in the AC system then you'll need to have one installed (call us if you need help).

At this point it is time to make an appointment with the a/c shop. The shop will:
14) Do a pre-inspection and then Evacuate (vacuum down) the system, the longer the evacuation the better but there is a point of diminishing return, 2-3 hours is generally very good.
15) The system will be checked for "gross" leaks while under vacuum.
16) Generally the system will be "initially" charged with approximately 80% to 85% of the original amount of R12, using R134a. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. The exact amount will vary with each car.
17) After the "initial" charge the system is then "tweeked" : you determine the optimum amount of refrigerant to match your system by monitoring the a/c outlet vent temperature and the high side pressure as you add or remove refrigerant. When the ambient air temps get above 80F the gauge readings can run a bit higher on the high side and lower on the low side when using R134a. You do not want to exceed the system's high side recommendations. The safe high side pressures are determined with a "PT" (pressures and temperatures) chart. This chart has a column of "ambient" (outside) air temperatures on one side and a corresponding range of high side pressures on the other side. The higher the ambient temperature the higher the high side pressure. By noting the ambient temperature you can look up what the preferred high side pressure should be.
18) Since you will be using less R134a than R12 you do not want to rely on the drier's site glass to determine if the system is full. With R12 you use to check to see if the site glass was "full", if it had bubbles it meant you had a low charge. With R134a you do not rely on the site glass.
19) After the optimum referigant charge is determinend the car should be test driven to check for performance of the system.
20) After the system has been tested out it should be checked for leaks. When you add fluorescent "tracer dye" to with the refrigerant oil it helps to track down leaks that push oil out of the system. By using a "black light" the dye will glow in areas where oil leaks are visible. The next piece of equipment to track down leaks is a "leak sniffer". This is an electronic tool that sucks in air through a tube and across a sensor. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. What is usually "sniffed" are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. Generally you follow the refrigerant flow moving from connection to connetion, component to component, and you sniff the a/c vents to check for evaporator leaks as well.
21) To "bless" the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. The sticker typically has a place to note the amount of refrigerant used, the type of oil and amount of oil, the technicians sign off or name and the date of the conversion. When ever possible you should ask the technician to note the same information on your repair bill and keep a copy in your glove box for future reference.
__________________
86 Red 944
85.5 Red 944(sold)

Last edited by mscromer; 06-25-2006 at 08:11 PM..
Old 06-25-2006, 08:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Ornery Bastard
 
Join Date: Sep 2001
Location: Bellevue, WA
Posts: 2,872
I used a drop-in replacement (Duracool) and it does an amazing job.
__________________
Shifting is an art. Learn it, love it, live it.
---------
Silver 1998 Volvo S70 T5 <- Daily (Anja)
Guards Red 1986 951 <- Seattle car (Gretchen)
White 1976 914 2.0 F.I. <- Prodigal car, traded away then brought back again (Lorelei)
Old 06-25-2006, 08:48 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Eldorado's Avatar
 
Join Date: Apr 2005
Location: Ontario, Canada
Posts: 4,553
duracool is the accepted replacement to R12. it doesn't require any special fittings.. just put in and go...
haven't heard a bad review yet!
ozone friendly, too...
__________________
Kyle

2008 Mini Cooper // '83 Porsche 944 // '01 Mazda Protege [sold] //
"Never break more than you fix!" - SoCal Driver
Old 06-25-2006, 09:30 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Sep 2001
Location: Tucson AZ USA
Posts: 8,229
If the R12 system is properly vacuumed, and the hoses/fittings/compressor hold a hard vacuum, it is possible to us the Interdynamics kit without disassembly. THe only real problem is the low pressure fitting which will not clear the alternator housing without a little Dremel work on said housing. I have done four older cars (including one each 924 and 944) and have had no problems as long as the sy
__________________
Bob S. former owner of a 1984 silver 944
Old 06-26-2006, 12:22 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Sep 2001
Location: Tucson AZ USA
Posts: 8,229
If the R12 system is properly vacuumed, and the hoses/fittings/compressor hold a hard vacuum, it is possible to us the Interdynamics kit without disassembly. THe only real problem is the low pressure fitting which will not clear the alternator housing without a little Dremel work on said housing. I have done four older cars (including one each 924 and 944) and have had no problems as long as the system was healthy in the first place. And, if problems arise, you have only lost a fraction of the cost of a new compressor!!
__________________
Bob S. former owner of a 1984 silver 944
Old 06-26-2006, 12:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
Registered User
 
Razorback1980's Avatar
 
Join Date: Nov 2005
Location: Houston, Texas
Posts: 2,944
Garage
Send a message via AIM to Razorback1980
I brought this topic up before and a large number of people are using duracool. I have not heard one person say anything bad about it.
__________________
Tom

1990 944S2 Cabriolet
2002 Chevy Silverado 2500HD
2003 Maroon Ford F350 dually
Old 06-26-2006, 04:12 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Feb 2000
Location: Kingsport, TN
Posts: 2,925
I've used Duracool for 12 years in my old Mercedes (that I sold last week) and for probably 8 years in my 944. It works very well. You only use about 1/2 as much as you do with R-12.

My house has a very slow leak in each of its systems. Last year I installed the R-22 equivalent in both systems. Works very well there too.

It is my understanding that pulling a vacuum on the system is not necessary with the substitute. The downside is only efficiency, not formation of acids which is what happens with R-12. I am not a chemist so I am only parroting what I have read here. The substitute does, however, absorb more heat per pound than R-12 does when it changes phase and operates at lower pressures.

Duracool works very nicely.
__________________
Lawrence
1986 951
2002 SLK32 AMG
1987 328GTS
2011 528i
Old 06-26-2006, 04:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Ornery Bastard
 
Join Date: Sep 2001
Location: Bellevue, WA
Posts: 2,872
Quote:
Originally posted by Lawrence Coppari
The downside is only efficiency, not formation of acids which is what happens with R-12.
Very close actually.

The R-12 and R-134a don't cause acids when mixed, their lubricants do. R-134a cannot carry the same lubricant as R-12 used, and the lubricant that R-134a used will create a gell-like acidic mixture when mixed with R-12 lubricant.

Duracool can carry the same lubricant as R-12, so there are no issues with the lubricants mixing.
__________________
Shifting is an art. Learn it, love it, live it.
---------
Silver 1998 Volvo S70 T5 <- Daily (Anja)
Guards Red 1986 951 <- Seattle car (Gretchen)
White 1976 914 2.0 F.I. <- Prodigal car, traded away then brought back again (Lorelei)
Old 06-26-2006, 10:22 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
arbita1's Avatar
 
Join Date: Aug 2004
Location: Mahopac, NY
Posts: 2,250
Garage
Just wanted to put this out there. Is Duracool not safe?

http://www.epa.gov/ozone/snap/refrigerants/hc-12a.html#q2
__________________
Matt.

83 911SC
85.5 944 NA - Sold
Old 06-26-2006, 11:13 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Ornery Bastard
 
Join Date: Sep 2001
Location: Bellevue, WA
Posts: 2,872
Quote:
Originally posted by arbita1
Just wanted to put this out there. Is Duracool not safe?

http://www.epa.gov/ozone/snap/refrigerants/hc-12a.html#q2
A few ounces of butane versus several gallons of gasoline... If I'm not worried about the gasoline, I'm not worried about the Duracool.

Besides, the ignition point of Duracool is higher than the ignition point of R-134a, that means that it's easier to set R-134a on fire than it is to set Duracool on fire.

Some EPA regulations are highly ignorant. Especially regarding refrigerants. For example, the "canned air" that people use to clean their computers contains R-134a. It is exactly the same stuff that is in the A/C unit in new cars. It is 100% legal to vent those canisters of "canned air" into the atmosphere. Venting the exact same chemical from your car's A/C system, you can be fined thousands of dollars. Same chemical, same exact chemical, but apparently it's magically dangerous if it comes out of an A/C system.

EDIT: Also note that while Duracool is not technically legal as a replacement for R-12, it is a legal replacement for R-134a. Again, it apparently magically becomes dangerous due to what was in the system before, not due to any actual properties that Duracool itself has.
__________________
Shifting is an art. Learn it, love it, live it.
---------
Silver 1998 Volvo S70 T5 <- Daily (Anja)
Guards Red 1986 951 <- Seattle car (Gretchen)
White 1976 914 2.0 F.I. <- Prodigal car, traded away then brought back again (Lorelei)

Last edited by AaronM; 06-26-2006 at 08:35 PM..
Old 06-26-2006, 08:30 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Sep 2005
Location: Connecticut
Posts: 258
anyone ever heard of freeze 12?

im guessing its the same as duracool, freeze12 is the only substitute i can find. I asked napa, autozone, pepboys, advanced auto parts, and all had nothing except for pepboys who has the freeze12 stuff. I talkd to a guy at napa about it and he said it explodes or somethin like that so i wanted to ask around here if anyone heard bad things about it or used it or if its the same as duracool and what not.
__________________
1984 Porsche 944
Old 06-26-2006, 09:17 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Registered User
 
Join Date: Sep 2005
Location: Connecticut
Posts: 258
o yea, and the fittings too....the top of the can of freeze12 is a screw on, looks the same as the r134a cans. My bro bought a kit for r134a for like 5 bucks on clearance at target and im wondering if i can use the freeze12 with that kit...that is if freeze 12 is safe to use...

thanks in advance
__________________
1984 Porsche 944
Old 06-26-2006, 09:19 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered User
 
Eldorado's Avatar
 
Join Date: Apr 2005
Location: Ontario, Canada
Posts: 4,553
freeze12 is basically just another hydrocarbon... it could potentially blow up, just like any other hydrocarbon under the right conditions... but then again, so could a stock a/c system..

i haven't heard any reviews on freeze12, so i wont promote it or reject it..
__________________
Kyle

2008 Mini Cooper // '83 Porsche 944 // '01 Mazda Protege [sold] //
"Never break more than you fix!" - SoCal Driver
Old 06-26-2006, 09:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered User
 
Join Date: Sep 2005
Location: Connecticut
Posts: 258
ooo thanks for the very quick reply there eldorado...hehe, here's a site i yahoo'd about freeze 12....


http://www.freeze12.com/

says its non flammable

any idea about the fittings?
__________________
1984 Porsche 944
Old 06-26-2006, 09:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Feb 2000
Location: Kingsport, TN
Posts: 2,925
If you want to purchase the hydrocarbon substitute, get in touch with Fox Tool Supply in Nashville, TN.
http://www.foxtoolsupply.com/
__________________
Lawrence
1986 951
2002 SLK32 AMG
1987 328GTS
2011 528i
Old 06-27-2006, 04:00 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Registered User
 
Join Date: Aug 2003
Location: Texas
Posts: 196
It seems to me everyone has their own opinion(which is perfectly fine) on which alternitive refrigerant to use. One guy says this refrigerant works and another says it doesnt. One person says its flammable another says its not, and worse some people say they dont know if its flammable. Personally, I dont trust these manufactures of these alternitive refrigerants. To me they are just trying to make a quick buck. For example, duracool's web site sure does make it sound safe yet the EPA has not approved it, Why? The 944 was designed for R-12, its been around for ever and we know it works. 134 will also work if you replace the condenser and we know it works and is approved by the EPA. Why not stick with what you know for sure works and that you can get it serviced anywhere. www.griffiths.com has the best website about Porsche a/c systems. below is some more great info from Griffiths including a photo of a Porsche that used an alternate refrigerant.


What about this other refrigerant I saw advertised?
Besides R134a there are some other refrigerants that are "approved" to replace R12 and there is a long list of refrigerants that are "not approved". The approval is very legal one, governed by the U.S. EPA. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician.


Approved list link is http://www.epa.gov/ozone/snap/refrigerants/lists/mvacs.html

The problem with using an approved alternative refrigerants other than R134a is that when the system is serviced it requires certain types of fittings, labels and dedicated equipment. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. This would become an expensive investment for a repair or service station to have unique dedicated equipment for everytype of alternative refrigerant.

Non approved list link is: http://www.epa.gov/ozone/snap/refrigerants/lists/unaccept.html

We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. The non-flamables can have R22 type gas which is not compatible with most rubber hoses or they have gases that contribute to global warming. The flamables have hydrocarbons.

Here is an example of someone who tried to use an alternative refrigerant that is "flammable". As you can see it can become a very expensive headache:

__________________
86 Red 944
85.5 Red 944(sold)
Old 06-27-2006, 07:03 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered User
 
arbita1's Avatar
 
Join Date: Aug 2004
Location: Mahopac, NY
Posts: 2,250
Garage
Looks like Freeze 12 is on the list of acceptable substitutes.

However, I was just reading their procedure, and you have to replace the service ports and dryer (recommended if more than 10 years old) anyway.

So why not just convert to 134a if you have to do that all anyway?
__________________
Matt.

83 911SC
85.5 944 NA - Sold

Last edited by arbita1; 06-27-2006 at 07:56 AM..
Old 06-27-2006, 07:18 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
 
Registered User
 
Join Date: Sep 2005
Location: Connecticut
Posts: 258
sure is! hence me running out as soon as i fix my radiator fan problem...they wont turn off!
__________________
1984 Porsche 944
Old 06-27-2006, 07:45 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Registered User
 
Razorback1980's Avatar
 
Join Date: Nov 2005
Location: Houston, Texas
Posts: 2,944
Garage
Send a message via AIM to Razorback1980
msmacromer....you must learn the difference between reality and marketing BS...including Griffith. Even R12 and R134 are combustible and that picture has been floating around for a very long time and if the truth were known (which it isn't) is that they were probably using R12 since the picture is so old. Just looking at the group of houses in the background, we probably were not dealing with a rocket scientist here either. And was the fire even from the refrigerant or a leaking gas hose? Who knows? Get the guy that owned the car to tell the whole story, then let's talk. I think a picture loses credibility when it's on a site that stands to make a dollar from sales. Especially Griffith. Hey, I have a picture of an beach in Arizona including a copy of the deed for sale...interested? Just because I have a picture, does that make it true? Don't believe everything you read...especially on the internet. Make sure the author has nothing to gain from what you are reading. The EPA? Ok, let's talk about the EPA. Can you tell me where their lab that tested these products is located? NO? That's because they don't have one. The EPA gets their data from companies such as DuPont that have the labs and they rely on that data to make decisions. Does DuPont want duracool approved? Why would they, they hold the patents for Freon. The EPA banned flurocarbons because they said they were depleting the ozone layer only to later find out the company that claimed that was full of crap. Many companies are now saying the same about R12...who is right and who is wrong? Who knows. But one thing I do know for sure...if they were wrong, they are not going to tell you. I can't think of too many government agencies that really are capable of doing things correctly...and that includes the EPA. I have many friends there including one that rides bikes with me and she is dumb as a rock...however she is getting ready to write legislation that is going to make it where you can't buy auto paint without a painters certification. Apparently too many people are painting cars in their garages without proper filters...at least according to Congress. Don't believe me...I'll give you her email and you can write her and ask (Kim.Teal@epa.gov). She has never painted anything in her life...yet she is making all the legislation concerning who can buy paint and acceptable rules of application. And when I asked her how to make a proper filter...her reply...I don't know. Real good group of people that EPA. The good thing to her though is she has some common sense and will at least try and find out what it takes for a proper filter although it's going to depend on who she asks now isn't it? The other people I know there don't even have common sense going for them. The one good thing I can say about them is that I feel like a genius when I'm around them! What I do know is that I have 40 or 50 people here that say they use duracool with no problems...I don't have anyone who said...don't use it, my car caught on fire. I have personally used Freeze 12, R12 and R134 all with success. I have yet to use duracool but from the words of the people who are using it, it's a good alternative and I have yet to hear a bad story...the only bad story is from Griffith's marketing...Hmmm, that should tell you something.

__________________
Tom

1990 944S2 Cabriolet
2002 Chevy Silverado 2500HD
2003 Maroon Ford F350 dually

Last edited by Razorback1980; 06-27-2006 at 08:52 AM..
Old 06-27-2006, 08:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 08:05 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.