.
Freon substitute?
Cargo Master
Joined: May 2001
Posts: 3,208
Likes: 13
Freeze 12 is a blend of 3 refrigerants with the main one being R22 (soon to be banned)
If you Convert to R134A you really need remove the old refrigerant replace the reciever drier with one compatible with r134A and remove a much of the old oil as possible. Add r134a oil either polyglycol or ester the old mineral oil will not be picked up and circulated with R134A which can cause the compressor to fail and the diseccant bag in the old reciever drier can come apart when r134A and its oil is put in the system causing the compressor to lock up. Then the system need to have a deep vacuum applied for a minimum of 30 mins to remove non compressibles and moisture. The oil used in the r134A system becomes corrosive when it comes in contact with water and will eat up aluminium evaporators so moisture removal is vital.
If you Convert to R134A you really need remove the old refrigerant replace the reciever drier with one compatible with r134A and remove a much of the old oil as possible. Add r134a oil either polyglycol or ester the old mineral oil will not be picked up and circulated with R134A which can cause the compressor to fail and the diseccant bag in the old reciever drier can come apart when r134A and its oil is put in the system causing the compressor to lock up. Then the system need to have a deep vacuum applied for a minimum of 30 mins to remove non compressibles and moisture. The oil used in the r134A system becomes corrosive when it comes in contact with water and will eat up aluminium evaporators so moisture removal is vital.
Post Fiend
Joined: Jan 2003
Posts: 9,748
Likes: 16
From: Connecticut
Originally Posted by RangerPilot
Rockledge, would that diagram be correct for my '94? 4.0L if it makes any difference. Thanks a ton.
RP
Zach
RP
Zach
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
The how to's of a 12 > 134 conversion are a bit like politics and religion. I've done 134 conversions; I like to swap the orifice tube (a potential debate all in itself), drain as much of the old mineral oil as possible and replace with the same amount plus an extra ounce or two, (the reason the 134 compatible oil is needed is because a R134 molecule is smaller than a R12 molecule and may result in a leak on the shaft seal), replace o-rings, and replace nothing else. Dryers get replaced on systems that have been left open to the atmosphere, but if a guy wants to reuse it just open it up to the air and place it in your oven at about 225 degrees for an hour to drive out moisture. Evacuate and charge. I've serviced all types of a/c for nearly 30 years and I've done 134 conversions starting 10 years ago. Never had a problem with a system I've worked on 
.
.
Last edited by CowboyBilly9Mile; May 5, 2006 at 02:12 PM.
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 332
Likes: 0
From: B'more
I purchased Freeze 12 on Ebay, three cans + adaptors for $34. Should arrive early next week. My plan? Dump a can in & see what happens...
System works, but short cycles. Jumped out the compressor clutch cycle switch at the suction accumulator and let it run for a minute, produced cool, but not cold air. So I'm fairly certain it just needs refrigerant.
The big question, is there a seat-of-the pants way I can tell when the charge is in the ball park? I haven't done any A/C work for 20 years, but used to run service calls in the summer for a contractor...
There's no sight glass on the system that I can find...
System works, but short cycles. Jumped out the compressor clutch cycle switch at the suction accumulator and let it run for a minute, produced cool, but not cold air. So I'm fairly certain it just needs refrigerant.
The big question, is there a seat-of-the pants way I can tell when the charge is in the ball park? I haven't done any A/C work for 20 years, but used to run service calls in the summer for a contractor...
There's no sight glass on the system that I can find...
Posting Guru
Joined: Jun 2004
Posts: 1,635
Likes: 0
From: Niceville, FL.
Agryphon, if you don't have gauges sloooowly add refrigerant until sweating on the suction line is within about an inch or two of the compressor inlet on a humid day. CowboyBilly9Mile, like you I change orfice tube sizes when converting from 12 to 134A. I also adjust the screw on the cycling switch about 1/8 turn CCW (on Fords) and install a new accumulator with desiccant compatible with R134A. I too bake desiccant in oven and reuse (but not when converting). I also use Castrol Polyolester as the refrigerant oil as I believe it mixes better with any R12 remaining in the system.
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 332
Likes: 0
From: B'more
I did get my hands on an appropriate set of gauges (R12/22/502). To check the clutch cycle switch, I hooked the low side gauge up and observed the compressor cycled on at about 25psi and off at about 50psi, so that seems to be within spec according to the service CD. I don't remember how to check super heat (it's been 20+ years). I'm looking at the temperature/pressure range chart, guess I'll see lower then normal on the high side with low refrigerant?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 332
Likes: 0
From: B'more
As a follow up, added Freeze 12 to the system, so far works great. Clutch cycles a little on low fan settings, but as the ambient temp comes up or with higher fan speed, it just runs... blows very cold. Time will tell as they say!
Posting Guru
Joined: Jun 2004
Posts: 1,635
Likes: 0
From: Niceville, FL.
Glad it worked for you. Only problem is now you've "contaminated" your system and if you have trouble requiring service by a licensed shop they likely either won't work on it or will charge big $ to decontaminate.
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 332
Likes: 0
From: B'more
I appreciate what you're saying, but I doubt I would pay anyone to work on the system anyway! Like most of you, I gotta live within my budget, and that means DIY where ever possible! This was quick and inexpensive, and even if not entirely correct, didn't involve blowing a freon charge into the atmosphere. I wouldn't do that, just as I would not dump oil, antifreeze or other automotive chemical inappropriately. So, it seemed a good compromise... Anyway, don't want to take this thread off topic, and thanks again to all for the very useful information!
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
Comingled R12 is the issue. Pure R12 can be reused and resold. Some think the filter/dryer needs to be replaced during a conversion; that is actually only required if a system has been open to the atmosphere for prolonged periods of time or if there were a situation that caused debris to build in the system. Refrigeration systems must be 100% clean internally as dirt will plug an orifice tube/exp valve as well as accerate compressor wear. The oil is only changed if there is a conversion to R134. Even at that, since all of it cannot be removed without much unneeded effort, many people comingle some of the new oil with the old mineral oil. The oil change is for sealing purposes (contrary to some internet myths circulating); this is why the system will seal without 100% mineral oil removal.
*The subject of R12 > R134 conversions is much like politics and religion. Normally there are no wrong answers but some folks do go off the deep end regarding the effort involved. No harm done other than in the wallet
.
*The subject of R12 > R134 conversions is much like politics and religion. Normally there are no wrong answers but some folks do go off the deep end regarding the effort involved. No harm done other than in the wallet
.
Posting Guru
Joined: Jun 2004
Posts: 1,635
Likes: 0
From: Niceville, FL.
8-10 years ago the only A/C service company in my area (that I know of) that "decontaminated" systems used a special recovery unit that evacuated the system and compressed the contaminated refrigerant to a liquid which was stored in cylinders. They then paid a hazardous waste disposal company to pick it up and get rid of it (supposedly not cheap). Their base "decontamination" charge was ~$100 but that may have included draining the oil and flushing the system.
Thread
Thread Starter
Forum
Replies
Last Post
