FooFighters92

iTrader: (2)

Hi so in Ohio it's been over 100 degrees every single day for just about two weeks. I'm ready to just pay the money for my ac.

About last year I found a shop that still handles R-12 and they filled up my ac. They called me and said my car was ready and I came back and it never once blew out cold air AT ALL...they however said that it was blowing out cold air, so it either all leaked out in about an hour or they were lying.

I took my car to another shop and they said I needed a new compressor and to convert to R-134a...and that's where I'm at today.

So what I would like to know is exactly what do I need for the conversion. I know I need a new compressor and I'm going to buy the conversion kit and freon from autozone or oreilly. I know I also need to vaccume the lines, where can I do this? I read something that you can rent a pump, basically I just want to know from somebody who has done this what are the steps that I need to do with a bad compressor and to convert to r-134a. Please from somebody who has done this conversion themselves!!!!! I don't want opinions on Freeze...or Autofrost or how I should stay with R-12...I just want help on the conversion please. Thank you

BlueWrath92

iTrader: (1)

You dont need a new compressor dont do it!, get a conversion kit from a local autoparts store. the only thing you need to replace are the 134a adaptors, the old ones screw out and new ones in. you would however need a shop to vacume out all the old oil and condensation before installing the 134a. Now did the shop say you need a new compressor because your current one is broken? that might be a diffrent story.

TTOP350

iTrader: (8)

You have a leak someplace and the shop should have looked 4 that 1st b4 doing anything.
Don't downgrade to 134a. R12 works waaay better. IMO

FooFighters92

iTrader: (2)

What are some good ways to check if the compressor is broken?

And also a way to find the leak?

Diggler86

Agree with what was stated, the shop should have checked to see if the system could hold a vacuum with the proper gauges. If it can, there should be no leaks. This is before they fill it up.

FSTFBDY

iTrader: (33)

If the shop said You need a compressor. Thats prob. your leak. Do you have a black light? some Yellow shooting glasses? If so check for green dye. Maybe they added some to check for leaks. Im sure you can find videos on youtube

I can't see a good shop leaving R12 in and not trying to upsale you on a new compressor before you left the shop. anyways..........

leak check the system. Get a new compressor and receiver / dryer while your at it. Get a good vacuum on the syetem and find yourself some r12 or a shop to do it for you.

kylet8020

Best bet. Rent a vacuum pump from advanced auto parts hope you have gauges your going to need them hook everything up. Let the pump do its job * pumping out the air and old oil* and let it sit for 30 mins or so till it drops the system down to -30 psi. After it reachs this close all valves on your gushes and let it sit again. This time a full 30 mins if the gauge does not move then you don't have a leak. If you do have a leak your goin to have to find it, you will need a black light and yellow glass's for this. Get a bottle of pag oil with leak dye in it. Hooking your bottle of pag oil up allow the vacuum in the system to pull the oil Thu with your light look for the dye showing you where your leak is. If a shop said u need a pump id check around the pump for leaks. They can leak at the clutch. After you determine where the leak is or that you don't have a leak it's time to fill it. If your system dead for a while I'd at least replace the Orpheus tube and dryer. Repeat steps to vacuum the a/c system down. Once all is fixed and your system will hold a vacuum the r134 parts will screw on the the old r12 nozzles, thus converting your system to r134 pulling down the system with the new nozzles with a gauge attached, refill the system I'd use the gauges to do this. Mission complete...

drdrdaddeo

I just finished doing the entire conversion myself on my restored '85 FB SE. Old compressor was shot, connector lines were leaking, and accumulator was rusted badly. I pulled off the condensor and the evaporator cores and had them pressure checked at a radiator shop...both were solid without leaks, and afterwards I manually flushed them myself with a readily available spray flush solution. I bought a new accumulator (which was already set up with a low side R-134a port), a new high pressure orifice tube (dirt cheap), and a new compressor (new compressors will run R-134a or R-12.....but no one ever uses R-12 anymore...its illegal, almost impossible to find, horrifically expensive, and environmentally caustic). I purchased a new high/low pressure hose assembly from Advance Auto ($71 and a 5 day wait after ordering) which bolted perfectly from the compressor to the accumulator and condensor core. Before bolting everything together, I added about 2oz of PAG 150 directly into the suction port of the new compressor and rotated the compressor 10-15 times (clutch facing down) to lubricate its internal seals. I then added 6oz of PAG 150 into the accumulator providing the total of 8oz of PAG oil which the system will need to prevent compressor burnout. I then bolted up the system solid (and screwed on the R-134a retrofit connector to the old R-12 high pressure port). I happen to own my own high vac suction pump and auto A/C guages, as both of which are required to complete the job. Attached the suction pump to both the low and high pressure valves and pumped the system at full vacuum for 1 hour to remove water condensation. Seal up the manifold system and shut off the vacuum pump to check the manifold guages for for vaccum leaks. Fortunately, I had no leaks, so I began loading R-134a (a total of 38-40 oz...3 1/2 cans) directly into the low side port. Because the low pressure cutoff switch (on the accumulator) prevents the compressor from kicking in when pressures are below 20 PSI, I simply shorted this switch allowing my compressor to run devoid of refrigerant (but fully oiled and thus protected by the aforementioned PAG-150). Temp was 95 degrees in Jackson, MS, so I charged the system fully through the low side port. Always make sure the high side vent is closed on the pressure manifold, or the system will send high pressure into your can of R-134a and it will explode in your face!! At full charge, my low side pressure (at 2000 RPM and A/C on max) was ~50 PSI, and high side was about 300 PSI.....and A/C was blowing about 45 degree air through the vents into the car.......job completed. nNecessary equipment to do it all yourself......a strong vacuum pump, a good set of A/C pressure/vacuum manifold guages, 8oz of PAG, 40 oz of R-134a, a functioning compressor/accumulator, a new orifice tube, a leak free, R-12/mineral oil-free a/c system, R-134a high and low side retrofit port adaptors, and enough experience and smarts to keep from blowing your fool head off. Unless you've got all of the above, you should get an experienced auto a/c guy involved. I've always simply added freon to my own auto a/c system as required (and have burned out new compressors by not understanding how the refrigerant/oil mixture works), but until yesterday I had never done a complete a/c build, vacuum, charge and start-up. Fortunately, I had no leaks because I carefully checked everything out in advance. Now, if your system isn't holding vacuum, or is leaking R-134 after a day or two, you've got an entirely new (and much more difficult) problem ahead of you. My advice is to first break the old a/c system down to its individual componants and check everything out in advance to avoid the latter situation. Having done that carefully, I was surprised at how easy the job actually was.

kylet8020

By adding the oil before you did a final vaccuum you pulled the oil out when vacuuming Yeh system down to add Freon. Oil and Freon should be added when you have the system vacuumed down.

Scorpner

iTrader: (4)

IMO, the first shop should have verified that it wasn't leaking before adding the R-12, and should be responsible for fixing that and recharging it at their expense.

hdis2002

iTrader: (1)

I second the suggestion about putting dye in the system. The compressor could be leaking but this system also has several O rings that could be the culprit. You can get an A/C O ring kit pretty cheap for these cars. It would be worth your time to go ahead and change them while the system is discharged. Just follow the pipes and everywhere you see a connection, there will be an O ring in it. If nothing else, it's good PM.

Steve

fasteddi

iTrader: (2)

Make sure you can get her to hold at 500 microns at the least to assure you dont have a leak. A simple Hg vaccum is NOT the way to check the system. If you pull it down to under 500 microns and she rises up to over 1000 then you either have moisture still in the system or a leak. Continue to pull the vac on the system and if you can not get it to hold after a hour or so of the vac hooked up you must fix the leak. Moisture in the system causes acid to form..not a good thing. I will probly get yelled at by someone but Micron guages are the only way to prove that mositure isnt present and that there is no leak, even the smallest leak will not show up on a Hg value. Trust me I've seen it alot. And I second trying to keep the R12 as it is way better then 134a by a landslide in hi/med temp cooling.

I hope you get here fixed. I live in northern ohio and it has been crazy hot. Finally some relief today though. Only in teh 80's.

Best way is probly using a dye as sugessted. In the field I use nitrogen or a R22 mix with a leak detector to check for leaks, but we all know the piping on autos are tight to find leaks on.

drdrdaddeo

Correction to kylet8020. Liquid PAG oil is not removed during vacuuming out of an otherwise freon-empty system prior to charging. In a fully charged automobile a/c, leaking or venting of freon does remove both freon and the compressor oil (i.e. the R-134a/PAG) dissolved in it. When enough freon leaks (or is vented) out, the system needs to be recharged with both freon and oil (i.e. PAG), and both are added through the low side port as gases under pressure. To convert from R-12 to R-134a, I feel it is best to first flush out all the R-12 and its normal lubricant, i.e. mineral oil, as that oil is incompatible with R-134a (and will otherwise pool as droplets throughout the system which will later clog up orifice tubes, expansion valves, and/or other small passages). Once the system is completely flushed of R-12 and mineral oil, PAG is poured into the open system as an oily liquid (not a gas) where its sits in the accumulator and compressor. Once the system is closed off at zero (i.e. atmospheric) pressure internally, there is still a lot of water (as vapor) inside the system due to moisture in the atmosphere (here in the south we often have 95% humidity days and the air's water content is very high). Subsequent vacuuming of the empty, sealed and completely clean (yet liquid PAG-filled) system removes only water vapors from the system (the liquid oil stays pooled in the compressor and the accumulator). It is not until the R-134a is added back into the system as a gas during charging through the low side port (aided by suction from the compressor), that the cycling gas/liquid R-134a begins mixing with the liquid PAG, dissolving it and allowing both to subsequently cycle normally between gas and liguid phases under the differing pressures within the evaporator core, accumulator and condensor. An alternative approach during R-12 to R-134a conversion (which should safely accomplish the exact same thing), is to fully evacuate the R-12 flushed, sealed system under suction without first adding any liquid PAG) as I did. Importantly, however, initial charging must then be done without the compressor running, and special cans of pre-mixed R-134a containing precise amounts of PAG oil in them, must be used. Such R-134a/PAG refrigerant is very expensive, and usually only used to top off systems which may be a bit low (as it maintains the appropriate freon/oil ratio). Using the latter mixture, the system can be charged from start-up with the A/C on, leaving the low pressure switch connected. As such, the compressor won't start running until the low side pressure exceeds 20 PSI. When it does, the circulating R-134a will already have adequate PAG in it to lubricate the compressor, thus preventing it from damage. Home a/c units have compressors with a separate internal reservoir for for their own lubricating oil, which never mixes with its refrigerant (R-22). Thus, oil/freon mixing and interface problems are never a consideration in home or appliace units, (unless their compressor fails). While I'm mainly a DIY a/c guy, I am actually HVAC-licensed in both auto and home systems (mainly so I am legal to purchase freon as needed for my occasionally leaking auto and/or home a/c units). For years I've maintained both my own automobile and home a/c systems. There is an on-line certification/testing process which is cheap and informative, and I've saved thousands of dollars over the years doing my own diagnostics and repairs. I am probably the only double-board certified physician/scientist in the USA who is also a certified a/c technician, electrician, plumber, pilot, and composing/recording musician. But if I'm so smart...how come I ain't rich?

Now I must also note that Fasteddi is completely correct in what he says about diagnosing leaks using vacuum and conventional Hg guages. The latter are far to insensitive for anything other than large leaks, but they may let you know in advance of expensive freon charging that such a subsequently debilitating leak is present. Otherwise, without micron guages, small leaks will not be detected with manifold guages. However, they will show up within days to weeks as loss of freon and/or cold air. Finding such small leaks is a major PITA and dyes, leak detector, etc. etc. must then be used. In theory such small leaks may seal off using various freon- containing sealants, and the reviews are mixed as to whether they will subsequently damage your a/c system. In a system such as my own, in which all the componants have been tested and/or are new, I would never risk using such sealants. In an old system, prior to major componant replacement, it might not be a bad first choice.

tom86iroc

iTrader: (1)

i went to a buddy shop that does a/c he charged me a $100 bucks to swap over to 134 and put a die in for later leaks you should do it before summer gets here casue they charge way over for supply and demand in the summer

drdrdaddeo

I completely agree. If you don't understand auto a/c and have the tools to do your own installation and repairs, the auto a/c mechanics have got you by the short hairs, and the hotter the summer, the greater they are in demand......whalla....the more exhorbitantly high their services are. P.S. R-134a at an auto parts store runs about $12 to $14 per 12 oz can. A/C mechanics charge about $25 per 12 oz can plus their customery hourly labor and shop charges.....often as high as $100 -$200 for a simple charge and over $1000 for a compressor replacment. Today as Sam's Club I saw R-134a being sold in 30 lb containers for $109......about $3.50 per pound ( or $2.65/12 oz)! This is ten times cheaper than what the shop mechanics will charge you, and if you do the job yourself, the labor is free. Its not rocket science folks, and it all cleans up nicely with just soap and water. Most importantly, you'll never be at someone else's mercy for your own comfort. Free at last....free at last.

fasteddi

iTrader: (2)

Just make sure you know what your doing thats all. No its not rocket science but it can be dangerous if you have no clue what your doing. Research is best but I completly argee on doing it yourself. My employer charges $79 a hour on top of a service call for Residential Hvac work. Thats not industrial(which we charge a ton for) or Mvac(cars which we don't do). So you will save alot to learn how to do it yourself, just be smart about it.

REF 134a is cheep indeed, you should see what wholesales charge at Hvac shops. Cheeper yet. Although I dissagree on picking up a 30lbs net can. That is alot of 134a for just vehicles. Im not sure what the charge is in a car but im sure its under 2lbs at the most since its a little pee shooter system. If you need to work on the system that much where you would justifly buying that much Ref then you have a large issue..leaks. This in reality if done right, should be a one time fix.

I can't say the last time I saw a 134a system that wasnt on a car... the only times are on huge chiller systems by Carrier. Such as this one. 300 tons of cooling capasity there with a 480lbs charge of R134a total on 3 little screw compressors. This is literly a small one that we PM. the largest is a 800 ton centrifical Trane unit. 2000lbs charge on that one.

drdrdaddeo

Right on, Fasteddi.....there are no substitutes for knowledge and experience. HVAC is damn dangerous stuff in the absence of either. Just properly using the manifold guages requires a fairly steep learning curve.....and I've been fooled more than once by my own inattention and forgetfulness. Not at all a trivial undertaking.....but definitely doable in the face of close attention to detail.

fasteddi

iTrader: (2)

I've had my number of close calls because I just wasn't paying attention to what I was doing. Im sure all Hvac ppl have done it many times, thats what makes us better and more careful.

For gods sake though take it from me, wear safety glasses, REF will blind you if you get it in your eyes, and the POE oil is no joke, takes the mosture right out of ya. Just be safe and learn, its fun stuff once you get a grasp on it.

Diggler86

I think this is a good video to start learning

http://www.youtube.com/watch?v=lglPJ...feature=relmfu

drdrdaddeo

The video link above is overal quite good and consistent with my thread above, but the video had one serious flaw. The mechanic did not clarify the amount or the mechanism by which refrigerant oil (as opposed to dye which he showed) is added during charge-up of a dry system. However, if you look closely at the can of freon in his hand, you will see that he is charging the system with a commercial can of R-134a which indeed contains refridgerant oil (exactly the alternative approach I described in my thread above). It is terribly important that the right amount of PAG oil is loaded during charge-up by any of several different mechanisms, to prevent failure of the compressor within 6 months. After viewing the video link above, I looked at multiple other U-tube videos all describing simple R-134a A/C system charging, yet none of them presented any useful information on the appropriate addition of refrigerent oil (PAG) to R-134a systems during dry charge-up.....very scary.

fasteddi

iTrader: (2)

Your right about the video.

Good thing to learn is what Virgin Refrigerent=no oil. And when its nessassary.

FSTFBDY

iTrader: (33)

Ya, I tried to find a good video of a evac and recharge for him but nothing good on you tube. I might have my buddy at work video my next service if I remember. We buy (4) 30lb bottles of 14a at a time. and usually (1) R12

Summer is here and I do a ton of A/C systems here in Fl. (automotive shop)

fasteddi

iTrader: (2)

Cool, your lucky I work on mainly R22 systems. Seen the prices on that stuff? Outragous. Hope if works out for ya.

FSTFBDY

iTrader: (33)

R22 around here is anywhere from $350 - $450 for a 30lb cylinder
Arnt they phasing out R22 and newer stuff using 410a

kiinda like the R12 vs R134a of the auto world.

fasteddi

iTrader: (2)

Yea they cut the supply of new virgin R22 by 50 % this year. Then should be down to 0% new supply by 2020.

We pay $350 a 30lbs tank also which is pretty normal. Compared to 410a... $110 a tank but 25lbs insted of the 30lbs. 410a has much higher pressures. Which can be a good and bad thing at the same time.

Alot of places are pushing 410a. There are so many blends anymore. 422d is a drop in we use alot as you can still buy 22 condensers and evaps. But hey will come dry charged with n20

FooFighters92

iTrader: (2)

Wow...thank you all for the detailed feedback. I will be tackling this soon with one of my buddies and letting you all know how it goes. Thanks again for the replies!

Fast355

iTrader: (2)

When R22 dries up my substitue will be Propane/ HC290 and isobutane R600A. Stupid low cost, more environmentally friendly, and better efficiency, as well as higher system capacity.

drdrdaddeo

Only problem is that it is explosive. Most home a/c systems are also built into the home heating system, which is usually flame powered by natural gas or liquid propane. Having an a/c system which uses flammable propane mixtures under very high operating pressures, in the very same mechanical system which is using an open gas flame, is an explosion waiting to happen in my opinion. R-22 is pretty inert, non-flammable, and works great. As long as the system is well-sealed, replacing R-22 is not necessary and thus not costly. And if the R-22 system does spring a leak, it doesn't explode in your attic. Someone please correct me if I'm wrong.

kd5bwp

You have to replace the Dryer if you want to have any life out of that system along with all the o-rings. They are cheap and are well worth replacing on a car that all the freon leaked out of.

Fast355

iTrader: (2)

It just turns into highly toxic, poisonous Phosgene gas.....ala WWI trench warfare gas

The air in the duct work of the evaporator should by no means come in contact with the flames of the heating system!! Otherwise you are getting CO poisoned instead and an explosion is the least of your worries.

Even in the event of a complete system release, you would have a hard time getting enough concentration to cause an issue with explosiveness.