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 > 911 / 930 Turbo & Super Charging Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Sep 2000
Location: Maryland
Posts: 861
R12 to R134

Today I stopped by the auto part store to see if I could get my hands on a can of R12 oil to lubricate my system but had no luck. The guy showed me a kit to convert to R134 and all it had was two cans, gauge and two fittings and he said that's all I would need. I remember it being more then that. Has something changed? I know I have to evacuate the old R12 out.
__________________
16 VW Touareg
05 Porsche Cayenne S
87 Porsche 930
84 VW Rabbit GTI
Old 08-19-2007, 12:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
GO DAWG GO's Avatar
 
Join Date: Jan 2007
Location: Inland Empire of the left coast
Posts: 1,263
Garage
BMAN

I know I have to evacuate the old R12 out.

You need to purge the system with a vacuum pump. Moisture will immediately contaminate your system and dryer.

R134 is not as efficient but will work and blow cold when your moving...

I would take it and have it done and tell us how it works

Thanks

Bob
__________________
1 bad 930
Old 08-19-2007, 01:47 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Jul 2003
Location: Back in B'ham, AL
Posts: 3,416
They did NOT tell you the truth. Don't do that.

If you mix both refrigerants it won't work = $'s.

I have used Duracool - since years ago - which is a refrigerant that mixes with R12 w/o ANY problems at all. As a matter of fact, yesterday it was 100+ here in B'ham AL and the system worked great!

I stongly recommend it!

Just add it on the low pressure side of the compressor as if it was R12.
Old 08-19-2007, 03:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Sep 2000
Location: Maryland
Posts: 861
Thanks... Where's the best place to pick it up at? How many cans do you think I'll need? The system is completely empty now. I'm trying to have my rear condenser fixed.
__________________
16 VW Touareg
05 Porsche Cayenne S
87 Porsche 930
84 VW Rabbit GTI
Old 08-19-2007, 03:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Jul 2003
Location: Back in B'ham, AL
Posts: 3,416
Look in the web for Duracool.

Your system should be "sound" for any refrigerant to work, all components in fairly good condition and tight. If you have leaks you're wasting your money.

I would buy the three can package or may be the six can. It is not that expensive.

Good luck!
Old 08-19-2007, 03:57 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Mar 2005
Location: Near Atlanta
Posts: 128
I would replace the receiver/drier because it is your filter and drier for the coolant and if it is original, it needs to be replaced. Also, use new oil and "O" rings on each fitting so that the "O" rings don't tear when turned. You can buy compressed A/C system flush at auto parts stores and you should clean the whole system out. It's about $15 a can. After that blow clean air through everythin to dry it out and get any small stuff out. Make sure your hoses are good or you will be wasting a lot of money and time.
__________________
911rudy
Old 08-23-2007, 10:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
Join Date: Oct 2006
Location: Chas, SC
Posts: 1,006
R12 -> 134a

If your system is not leaking , buy a couple of cans of R12 off ebay and top it off every couple of years. Even if you are paying up to $25 a can so what, if the system does not leak, just keep buying a can every couple of months to keep a small stock, then if you have to top it up every year or so no big deal, and much cheaper than doing a "correct" conversion. Cools better and does not leak thru the barrier hoses like 134 does. This was my solution and works great for me and all of my R12 cars!
__________________
Tim
1986 930
Gone:71,2,4 914's, 70T, 71T(RS),77S
Old 08-27-2007, 06:27 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
kuehl's Avatar
 
Join Date: Aug 2004
Location: Stuck in NJ
Posts: 2,976
Garage
You have several options to get your ac system up and running. However how effective of a system you want will depend upon your climate needs; do you use the system often, are you in a hot climate, etc.

With R12 the refrigerant oil was what they call a mineral oil whereas R134a uses either "ester" or "PAG".

R134a requires a different desiccant (what is in your receiver drier) and requires different service charge ports (ref: your schrader valves).

Why you would want to "lubricate your system" .... I don't know. Normally the system is a closed loop system; it does not consume oil alike an engine. The only time you need to add oil is when you have had a refrigerant leak or you have replaced a component. The oil circulates through the system with the refrigerant and constantly lubricates the compressor; the compressor does not have a sump. But I don't want to discourage you from thinking about your systems ac oil... its a good idea since many of our 911's or or 930's have been passed down to many owners and the ac system repair history is vague; in many instances someone may have "topped off" due to leaks however they failed to add oil.

R134a condenser side pressures tend to run on the average (industry jargon) 10% higher than R12. Hence you either use less refrigerant or use a higher capacity or efficiency condenser system.

There is an option for you if you simply needed to add a lubricant other than mineral oil, you could use "ester" refrigerant oil. Esters tend to mix with mineral easier than PAG and it is very common to simply add ester when converting to R134a refrigerant. In a perfect world (you got the time and money) you would flush the system to remove contaminants that collect over the years (drier desiccant break down, compressor break down and hose break down) in the hoses, condenser and evaporator (you don't flush compressors or driers) prior to converting to an alternative refrigerant. However, its a proven fact that flushing is not necessary for a simple R134a conversion.

A "simple" R13ra conversion requires removal of the compressor, dumping of whatever oil remains in it (usually little), replacement of the receiver drier with a new drier that has R134a compatible desiccant (XH7 or XH9 desiccant), replace any o-ring on any port you have opened or component connection you have opened with o-rings made from HNBR (Hydrogenated Nitrile Butadiene Rubber), evacuate system for 3 hours, charge with a nominal amount of 85% by weight of the original R12 charge using R134a (example: if the system originally used 39 weighted ounces of R12 you would use 33 ounces of R134a) and fine tune (add or remove refrigerant) the charge based on an R134a Pressures and Temperatures chart.

Adding R134a to a system that has R12 can be done however its not recommended; when R12 and R134a are mixed together they form a high pressure azeotrope. This means that together their pressure is higher than either by themselves.

Getting back to the basics, a 930 has over 40 feet of refrigerant hose. The original hose is what we call "non barrier"; designed over 50 years ago; leaks or permeates refrigerant over time. So no matter what you will be constantly topping off or recharging your system since the stock hoses simply leak (the leakage rate or permeation rate is based on pressure, temperature and time). The solution is replacement with new barrier hoses.

Feel free to PM if you need more guidance.
Old 08-29-2007, 03:58 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 09:13 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, 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.