Model 5910717 C-60 and accessory 3.25 lbs C-69 4.50 lbs
I've did a bit of research on the 134 conversions and there are SO many kits to do it with that I don't know which one to use. Some have just the refrigerant, some have refrigerant and oil, some include special manifold pressure gauges and some claim that it's necessary to use their a/c system flush (a type of detergent) before switching.
I guess my real question is where do I begin? The a/c system is working now, but doesn't work so great in very hot weather. Although my Chilton's says so, there doesn't appear to be a sight glass on the system.
Also I'd like to verify basic steps. Off the top of my head they are: Reclaim R-12, replace receiver/dryer, draw vacuum on system, "inject" refrigerant and oil, and of course replace the hi/lo pressure fittings goes somewhere in there.
I would bring the vehicle to well equip garage that specialize on AC work. (someone you can bring the vehicle back should it goes wrong after conversion!) I have a bad experience with one few years back because I want to save a few bucks. Here are a few things I have learned from my mistake and hope that you won't:
1/ Check for system leak before conversion.
2/ Make sure the old oil is removed from the system since they are not compatible
3/ Add die if possible to ensure you have a way to check for leak later. Usually system leak does not occur when the compressor has been on for a while (high pressure build up die to heat)
4/ I had to replaced my accumulator as claimed by the garage.
5/ New conversion kit
As mentioned, since you can not do this yourself, so go find a good garage is all you can do. Check for guarantee coverage.
If the compressor is working and the system is just a bit low on Freon the smartest thing you could do is just keep paying an A/C shop every year to top it off with R12.
To really do a conversion right, here's in general what needs to be done:
1) Pull all flexible hoses off all fittings and replace them with modern A/C barrier hose. Some factory crimp fittings never were barbed, you need to cut off the nipples and braize on barbed nipples, any A/C shop can do this. It's OK to use worm-gear clamps on A/C hoses that are on barbed nipples as long as you check the tightness of the clamps every spring when you check the A/C system. Otherwise, any A/C shop can crimp on new barrier hose to the fittings.
I have used worm clamps on the smoother non-barbed nipples, but I've wired the hoses down to the fittings with steel wire. I did that before discovering the braizing trick.
Old A/C line will leak R134a plus it can be oil-saturated. And particularly if there's the slightest trace of oil on the outside of the hose, usually near the crimps, the hose is leaking. Over a long time - 20 years or so - the vibration will eventually loosen up any A/C line crimp.
If your really cheap and the flexible hose is in excellent condition, you can flush the hose out with mineral spirits and it will work, but R134a will pass through the hose wall (at a very slow rate, however)
2) Replace the receiver/dryer or accumulator (depending on which your system has) with a new one. Replace R12 fill fittings with R134a adapters.
3) Flush ALL steel lines in the system with at least a 1/2 gallon of pressurized mineral spirits blown through the line with compressed air. There's a tool on the market for doing this. Don't reuse the mineral spirits for flushing, but you can re-can it and let it settle and use it for cleaning around the shop.
4) Replace all O rings in the system with new ones that are compatible with R134a & PAG oil.
5) Replace compressor with a new one (you will never get all the old oil out of an old compressor)
6) Reassemble system and pull at least a good 3-4 hours of vacuum on it.
7) Add in new PAG oil of correctly measured amount and pull another hour of vacuum on it.
8) Introduce refrigerant into high side fitting while you have your vacuum running on the low side until R134 is coming out the vacuum and all air has been purged, disconnect refrigerant can and vacuum, close high pressure side, fill system with correct amount of refrigerant, sweep system with leak detector, run system for 15 minutes until you get a pressure baseline, then shut her down for a couple days, and then reconnect a manifold set and remeasure pressures to make sure you don't have a slow-leaker.
And of course, make sure to release as little as possible refrigerant to the atmosphere, espically R12, have a shop reclaim that before you crack into the system.
So as you can see your in at least 6 hours of labor on this, plus close to $1000 in parts, plus a bunch of tools.
A lot of people have pulled the trick of instead of using PAG oil, they use Ester oil with R134a. Ester is somewhat compatible with SMALL amounts of mineral oil. Of course, all this assumes a compressor that does NOT have an oil resivor. (I don't think yours does) I frankly don't understand this mentality - if your going to go to R134a then fine, do it right. Otherwise stay on R12.
I don't believe in introducing dyes into the A/C line either, a good electronic leak detector and a lot of patience is the way to do it. Keep in mind that very small leaks may outgass at such a small rate it would take months before enough oil would be carried out to stain the outside for dye to be noticed. Also a lot of these dyes are UV ones and you need a blacklight for them, and the place where the leak is may be on the underside of a hose that is very difficult to see.
And to my mind the idea of flushing the system without taking it apart and running compressed air through each segment to make sure they are bone-dry is nutty.
Most systems that used a receiver/dryer on the high pressure side have sight glasses. Systems that use an accumulator on the low pressure side generally didn't.
I'd begin by disabusing you of the notion that you can do a successful conversion with a "kit" of any sort. They're disasters.
What you need to do is:
1) identify WHY the system isn't working "so great" right now. If its simply low on R-12 (manifold guages would reveal this) and has NOT been deteriorating rapidly, then by far your cheapest and best option is to LEAVE it R-12 and have it charged up. If the poor performance came on suddenly, then you probably have a leak and should NOT recharge until the leak is found and fixed.
2) If the reason you have poor performance now is NOT fixed, performance will be 10 times worse on R-134a. If the problem is major, such as a compressor failing, then it might be economical to consider an R-134a conversion.
3) If you decide to convert, completely dismantle the system after having the R-12 reclaimed. Remove all hoses, the accumulator/drier, compressor, and orifice tube. Flush the condensor and evaporator THOROUGLY with an R-12/R-134a compatible flushing fluid (available at Pep Boys, believe it or not). Also flush the hoses themselves, but NOT the compressor if you plan to re-use it, but do drain all the oil you can out of it (I'd recommend a new compressor, personally- its going to work harder than it ever has before when you convert to R-134a.)
4) Begin reassembly using all new O-rings and seals, a new orifice valve (preferably a SmartVOV type, if you want anything near decent cooling). Replace any leaky hoses. Install a new accumulator/drier, install R-134a fittings.
5) Fill the compressor with high-quality R-134a compatible oil (the safest bet is ester-based oil, although "double end capped" PAG oil may be OK). DO NOT let the system sit open for any length of time after adding the oil- R-134a oils are as hygroscopic as brake fluid and will absorb water from the air. Add the oil IMMEDIATELY before you assemble the system.
6) Pull a vacuum on the system and hold it for an hour.
7) Re-charge with 60% by weight as much R-134a as you would have used if using R-12 (see the vehicle manual).
A system converted this way should have a reasonable life expectancy and should perform acceptably, although maybe not as well as with R-12. If you use a kit, expect the system to fail in 6 months to 2 years at most.
Bullhonk! Anyone with good mechanical skills can do an excellent conversion. Most people would have to buy a set of manifold guages and rent a vacuum pump, but I would trust my own conversion 100%, because I KNOW what has been done and KNOW that no shortcuts were taken.
Actually, its not a question of ester being compatible with mineral oil at all. The problem with PAG is that it is HIGHLY reactive with any trace of chlorine left in the system from R-12. Chlorine destroys PAG oil over time, and the system can fail due to the oil becoming an abrasive sludge, even after being flushed. "Double end capped" (a term for a chemical stabilization process) PAG oils are MORE immune to chlorine attack than regular PAGs, but not necessarily immune over the long haul (the jury is still out on that).
Ester oil is a compromise. It doesn't lubricate quite as well as PAG (which itself doesn't lubricate quite as well as mineral oil) but it DOES NOT break down when exposed to clorine residue. In fact, it will work fine in an R-12 system, although it would be silly to use it there when mineral oil is so much better. But the good thing about it for conversions is that you can be assured that it won't break down. It may never be a super great oil, but its good enough and it won't turn to sludge like PAG oil may. It will be as good in 10 years as it is when you put it in, which you can't say about PAG.
In my mind, using POE (ester) oil is "the right way" to do a conversion. If you're installing ALL new components, then sure, use PAG. But not for a conversion.
||4) Begin reassembly using all new O-rings and seals, a new orifice valve ||(preferably a SmartVOV type, if you want anything near decent cooling). ||Replace any leaky hoses. Install a new accumulator/drier, install R-134a ||fittings.
Is this some sort of aftermarket variable orifice? What is it good for?
Orifice tubes have always been crude but cheap/rugged replacements for a true expansion valve that varies with compressor speed and thermal load. Orifice tubes worked fine with R-12 where there's a big surplus of heat removal capacity, but when you convert to R-134 the surplus is gone and cooling gets very persnickety with respect to engine speed. The VOV adjusts itself to compensate and helps converted systems work at idle in traffic where a non-variable orifice tube will just quit cooling.
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