Is there any way to differentiate between the two (in an a/c system)? I bought a '89 Blazer with a new compressor and accumulator/dryer and it's low. I don't want to add the wrong type and lock up the compressor. I'm too lazy to drain it and start all over. It doesn't have the larger quick-connect type fittings, but I find it hard to believe they put R-12 in it.
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R-12 vs R134a 1
- Thread starter iwmob
- Start date
In order to retrofit an R-12 system it is necessary to change the fittings to the R-134 type. The probability is that your system has NOT been retrofitted.
Why do you find it difficult to believe that R-12 could be in it? R-12 is still available on a limited but costly basis.
"I am too lazy..." What a statement to make in an engineering forum.---
You want US to sort it out for you!:-(
Rod
Why do you find it difficult to believe that R-12 could be in it? R-12 is still available on a limited but costly basis.
"I am too lazy..." What a statement to make in an engineering forum.---
You want US to sort it out for you!:-(
Rod
- Thread starter
- #3
Shaun, I have converted several systems to R-134 mostly with excellent results. It appears that any system that has excess condenser capacity adapts the best. My Dodge/Cummins duelly, my 454 BBC motorhome and, my son in laws big block Dodge powered motorhome are the best but a couple of little Ranger pickups have also been excellent. I lived in Eueless for a time so I know it gets pretty hot and humid around your area and the demands on the cooling system is severe. Perhaps your system is not functing at full capacity or was not properly converted. If it's pumping/condensing capacity is just to low--no cure for that aside replacement ($$$)! Might be cheaper to trade for a later model vehicle if there is no emotional attachment to the one you have.
Rod
PS---The Dodge/Cummins was converted with the Castrol kit about four years ago and is still functing well. It was 118f here yesterday.
Rod
PS---The Dodge/Cummins was converted with the Castrol kit about four years ago and is still functing well. It was 118f here yesterday.
I have not owned any vehicles that have been converted. Dad has, and he and I both complained. I understand what you mean about the system not being totally right. With most of the cars he buys for quick fixes and then resale, who knows what short cuts he or the previous owners have taken. One think I hope we all agree is that you get what you pay for.
Shaun TiedeULTRADYNE Arl,TX(stiede@ev1.net)
Shaun TiedeULTRADYNE Arl,TX(stiede@ev1.net)
Shaun, from my experience many people do not know that you only fill a converted R134A system to 75-80 percent of the old R12 charge. If you overfill, performance is degraded significantly, IMO.
Also, make sure whoever changes your system over holds vacuum for at least 30 min to boil off as much humidity as possible, humidity in your system is also an enemy.
Also, make sure whoever changes your system over holds vacuum for at least 30 min to boil off as much humidity as possible, humidity in your system is also an enemy.
SammyDaFish
Mechanical
iwmob, if you think they were to cheap to put R-12 in, then test it. They probably put propane or Freeze-zone imitation stuff in there. It's cheap, but you can;t recycle it unless you have a junk tank to do it in. I bought a freon test machine from snap-on. I test every car before I work on it, especialy the old R-12 systems. There's no way I'm taking the chance of loosing a $2,500 tank of freon for some shmoe who decided propane would work ![[evil]](/data/assets/smilies/evil.gif "[evil] [evil]")
I am no expert on car AC but I have worked on domestic & commercial refrigeration where I have replaced R12 with a straight drop in replacement R49. This tends to require about 10% more volume and pressures tend to be about 10psi higher. No change in performance has been experienced. I have used R134a with satisfactory results but not as a retrofit.
JayMaechtlen
Industrial
..."you get what you pay for"
only if you are carefull and informed or lucky!
Otherwise you can pay a lot and get very little.
I have done two bare-bones 134a retros so far. Both work great! The '89 Aerostar dual-air has original compressor and works pretty well. I flushed way too much money paying "professionals" to fix it previously- (would hold a charge for about a year), this time I just used the new oil, a seal conditioner/stop leak additive, and the fittings. Works great so far!
The '91 Buick Century ran low on R12, so I did the same- so far, so good!
On both units, most "professional" shops would charge many hundreds of dollars (US) for a fairly minimum job. Add $400-600 for new compressor if they felt it was needed.
Not my car you don't!
Jay Maechtlen
only if you are carefull and informed or lucky!
Otherwise you can pay a lot and get very little.
I have done two bare-bones 134a retros so far. Both work great! The '89 Aerostar dual-air has original compressor and works pretty well. I flushed way too much money paying "professionals" to fix it previously- (would hold a charge for about a year), this time I just used the new oil, a seal conditioner/stop leak additive, and the fittings. Works great so far!
The '91 Buick Century ran low on R12, so I did the same- so far, so good!
On both units, most "professional" shops would charge many hundreds of dollars (US) for a fairly minimum job. Add $400-600 for new compressor if they felt it was needed.
Not my car you don't!
Jay Maechtlen
SammyDaFish
Mechanical
A new compressor is not needed, and really, never should be unless it's physicaly bad. No reason to change it for a 134a swap. It's recomended to replace the receiver/dryer as oil tends to accumulate in it and R-12 and R134a oils are incompatable. I have seen some problems with domestic cars and 134a retrofits as the 134a is made up of finer particles, it tends to actualy leak out of cheaper hoses. Other than that, it ususaly works just fine. r134a does tend to not cool as cold as r12 when put in an r12 designed system. This is understandable though, since the system was not designed to use the newer refridgerant. Sometimes it's hard to explain that to a custoemr though :-/
JayMaechtlen
Industrial
ok- I have heard thiis before:
" R-12 and R134a oils are incompatable"
but Interdynamics claims, on (an FAQ) that there are acceptable upgrade paths.
Also see
"Pressurized Ester Oil Charge for R-134a"
The Ideal Lubricant for All Retrofitted and Factory Installed Systems
EZ-to-Fill System
All Oil Charge Cans Use Same Acme Threaded Can Top as R-134a Refrigerant Cans
Easily Dispensed with the Same 134a Can Tap Valve and Hose or R-134a Manifold Gauge Set
Single viscosity for Minimum Inventory
Compatible with R-12 and R-134a Systems
Miscible with Residue of Mineral Oil and Stable with All Levels or R-12
Less Absorption of Moisture than PAG Oils
No connection with the company, but they have some very well-written material on the site. And- seems to work.
Jay Maechtlen
" R-12 and R134a oils are incompatable"
but Interdynamics claims, on (an FAQ) that there are acceptable upgrade paths.
Also see
"Pressurized Ester Oil Charge for R-134a"
The Ideal Lubricant for All Retrofitted and Factory Installed Systems
EZ-to-Fill System
All Oil Charge Cans Use Same Acme Threaded Can Top as R-134a Refrigerant Cans
Easily Dispensed with the Same 134a Can Tap Valve and Hose or R-134a Manifold Gauge Set
Single viscosity for Minimum Inventory
Compatible with R-12 and R-134a Systems
Miscible with Residue of Mineral Oil and Stable with All Levels or R-12
Less Absorption of Moisture than PAG Oils
No connection with the company, but they have some very well-written material on the site. And- seems to work.
Jay Maechtlen
If memory serves, we had this same discussion several times and as far back as three years ago(a search may turn it up) and the R-12 compatable oils were available then. My first conversion was in 1999 and cost me about $60 my last was 2002 and was $29 !!! If you do not have access to a vacuum pump or guages then you will need to take rental costs into account but, in no way will I pay the $600 to $900 qoutes I received from several SoCal auto shops!
In my personal experience so far---No problems with oil compatability---no problems with dryer/accumulator contamination---no hose problems with "molecular migration" ( a bogus idea, the "boogy man" IMO)---no "freez ups" due to moisture contamination---no compressor failures---no leaks save one Shrader valve replacement.
I feel for the PRO shops in this but, in most cases I see the conversion kits at Wal-Mart or Pep Boys (Autozone, whatever!) work a majority of the time if installed by any reasonably equipped car nut, ie. at least a couple of warm brain cells. If the pro shops around here would charge a reasonable price , taking into account overhead, liability, labor, etc. costs there is a "ready" market out there, ie. the majority that lack the above warm brain cell qualifications.
Rod
In my personal experience so far---No problems with oil compatability---no problems with dryer/accumulator contamination---no hose problems with "molecular migration" ( a bogus idea, the "boogy man" IMO)---no "freez ups" due to moisture contamination---no compressor failures---no leaks save one Shrader valve replacement.
I feel for the PRO shops in this but, in most cases I see the conversion kits at Wal-Mart or Pep Boys (Autozone, whatever!) work a majority of the time if installed by any reasonably equipped car nut, ie. at least a couple of warm brain cells. If the pro shops around here would charge a reasonable price , taking into account overhead, liability, labor, etc. costs there is a "ready" market out there, ie. the majority that lack the above warm brain cell qualifications.
Rod
JayMaechtlen
Industrial
uh-
yeah, I seem to recall something about that...
I guess my brain cells weren't warmed up yet!
cheers
Jay
![[upsidedown]](/data/assets/smilies/upsidedown.gif "[upsidedown] [upsidedown]")
Jay Maechtlen
yeah, I seem to recall something about that...
I guess my brain cells weren't warmed up yet!
cheers
Jay
Jay Maechtlen
SammyDaFish
Mechanical
I've heard of some people talk about $700+ conversions. That, I agree is ludacris. My shop charges a few hundred at most for most jobs, depending on the time involved and if we need to replace anything. Remember that if you were to just do a conversion, you Legaly can NOT do it at home. The reason why? It's against federal law to release r-12 into the atmosphere. If you have an operating system, and want to do the swap, you need evacuation equipment. Most of the time though, you do a conversion because something failed in the system and the refridgerant leaked out. In this case, you must repair the system. This can be costly. If you repair the system yourself, you'll have to pull a vaccum on the system for a while to make sure there is no moisture in it. You will get freeze ups if you don't do this. As far as the pourous hose issue, dye tests have shown bad hoses (low hose on a caravan is a popular one to go bad). All in all, I believe the "do it yourself" kit is a bad idea. The main reason beeing that you let untrained people deal with serious enviormental hazzards, and after all, that was the whole reason r-12 isn't made anymore anyway. There are many ways that you can save a few bucks, ruining the atmosphere is not a good way to do it.
Like I said, I feel for the pro shops that honestly try to do the job at a fair rate. If your one of those shops then in my opiniion, you are one of the few. Just about every shop I went to (the exception in a second) wanted $600 or more to retrofit the system on my old Dodge. The kit was only $40 and the dye check and replacing the Shrader valve a few more bucks. As to draining the R-12 I took it to the local Ultramar station where Robert suctioned the system and pulled a vacuum in exchange for the two or so pounds of R-12 remaining in the system. At the going rate for the R-12 it was a pretty sweet deal for him and a good deal for me. Everybody was happy. I did the retrofit in the summer of 1999 and I just now got back from Anaheim---still works perfectly. The three other conversions I did were on systems that had some sort of catastrophic failure in a fittilng or hose. The vacuum pump was a "loner" and I am told they can be rented. I have my own guages and the adapters to fit R-134a systems.
From the point of view of any professional shop I guess the idea of the DIYer is not particularly welcomed. I don't know what to say to that.
As to the R-12 being the root of the "hole in the ozone", after several years of wide spread restrictions on the use of flouro carbons including R-12, you would think we would see a substantial improvement in the situation, would you not? Funny, last I looked it was getting worse!
Rod
From the point of view of any professional shop I guess the idea of the DIYer is not particularly welcomed. I don't know what to say to that.
As to the R-12 being the root of the "hole in the ozone", after several years of wide spread restrictions on the use of flouro carbons including R-12, you would think we would see a substantial improvement in the situation, would you not? Funny, last I looked it was getting worse!
Rod
JayMaechtlen
Industrial
The typical leaky auto A/C system seems to hold R-12 for a year or two. If, with the seal conditioner, it holds R134a the same period of timme, then why would you bother trying to get the system perfect?
Convert the fittings, a quick pumpdown, load the new oil, seal conditioner, 134a, and you're done!
top the refrig every year or two, and you're fine.
ozone hole? well, not all the CFCs have migrated out and broken down yet, perhaps. I don't know what the transport time is, or how much CFCs still need to get broken down.
Anyway- for MOST car owners, a simple conversion should be ok- but they should have someone do it because MOST ownes have little or no clue about the process...
cheers
Jay Maechtlen
Convert the fittings, a quick pumpdown, load the new oil, seal conditioner, 134a, and you're done!
top the refrig every year or two, and you're fine.
ozone hole? well, not all the CFCs have migrated out and broken down yet, perhaps. I don't know what the transport time is, or how much CFCs still need to get broken down.
Anyway- for MOST car owners, a simple conversion should be ok- but they should have someone do it because MOST ownes have little or no clue about the process...
cheers
Jay Maechtlen
Jay, the AC system on my 85 Silver Eagle 454 BBC was "at specs" when I checked it in early 2001. I put in a fan belt that was an inch longer than standard (to make it easier to install?) and the results were a pully rubbing a hole in the low pressure line (DUH!!!). I did a hose replacement (and a shorter belt) along with a "quickie" R-134 conversion, all within a few hours of the break and the system functions as it always did. No problems last time out end of June, 2003. Perhaps the seals on this one are better than the average (I sure hope so). This vehicle often sits unstirred for many months at a time, once for over a year, and it still works!
Total cost---$29+tax Castrol kit---hose $15---fan belt ?---one box of Band Aids and a tube of Neosporin ointment :-(
Rod
Rod
Total cost---$29+tax Castrol kit---hose $15---fan belt ?---one box of Band Aids and a tube of Neosporin ointment :-(
Rod
Rod
JayMaechtlen
Industrial
well- sounds like yours is tight- that's great!
My '89 Aerostar started getting leaky at 4-5 years old?
I forget, but it was out of that part of warranty...
converted at 155,000 miles, quite recently.
My 80(?) Fairmont held refrigerent fine- but the compressor died at ~80,000 miles, and I never fixed it.
'89 Century - compressor died at ~150,000 miles.
'91 Century - leaky at ~110,000 miles, converted at 130,000 miles.
Funny how some systems seal perfectly, others just refuse to!
Jay Maechtlen
My '89 Aerostar started getting leaky at 4-5 years old?
I forget, but it was out of that part of warranty...
converted at 155,000 miles, quite recently.
My 80(?) Fairmont held refrigerent fine- but the compressor died at ~80,000 miles, and I never fixed it.
'89 Century - compressor died at ~150,000 miles.
'91 Century - leaky at ~110,000 miles, converted at 130,000 miles.
Funny how some systems seal perfectly, others just refuse to!
Jay Maechtlen
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1
- #20
there is a drop in that will work on both types of systems whther it is r12 or r134a. It just got approved to be used in cars it is r414 (hot shot) I have tried it in bothe sytems and it works fine. Bonus is that you dont have to change oil. compatible with both types.
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