The system will be checked for gross leaks while under vacuum. After the system has been tested out it should be checked for leaks. Crap! It is possible I have 10 ounces (250 ml) in the system. Though you can purchase 12 or 16 ounce cans of R134a from local retailers it is very difficult to measure out the correct amount into your system. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. On the other hand, R12 has a global warming potential of 10,910. What effect would it have on performance, if any?At the moment, the ac is acting up - will work fine for about 15 minutes and then slowly the vent temperatures rise until the compressor switches off. . 10,000BTU conduction heating? Bookmarks: Digg; del . I don't know where it is getting the switch off command, or why the vent temp drops steadily. Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound? We, the Rxmechanic team, have presented a well-detailed comparison of R134a vs. R12. The whole trick is to sit there in those steam boxes and not perspire, it's vulgar to perspire when driving on public roads.If you want esteem, drive an MB, if you want comfort with 60*F interiors in a 125*F environment, get a Caddy. R12 is simply too expensive for a 25+ year old A/C system. Answer: OK, I'll bite. When ever possible you should ask the technician to note the same information on your repair bill and keep a copy in your glove box for future reference. I think so. In this study, without the need for major modifications to the bus air conditioner, the variation of the ejector dimensions according to different parameters has been investigated in the case of using the R1234yf, R1234ze(E), or R600a refrigerants, which may be a substitute for R134a as a refrigerant due to . Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). 42 (at best) w/ 134A in 2000 isuzu trooper. Besides R134a there are some other refrigerants that are approved to replace R12 and there is a long list of refrigerants that are not approved. One of the differences between auto air conditioners that have been redesigned from R12 to R134a is that the condensers have gone from serpentine to pseudo-parallel. The cure is to use the newer R134a compressors is sealing washers that are different thickness. James10952001. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. 1) Warm Air From Vents. The symbol implies that R12 is a composite of carbon, chlorine, and fluorine. Back in that era, my business associates drove those things, brand new, and maybe I should take my Cadillac instead, no they wouldn't be caught dead in a Caddy, people of our esteem should be driving an MB. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. Yes it will work with either Refrigerant! Big . An extra half ounce? You can spend long evenings reading about the differences between the two refrigerants. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues. There is a lot of differences between the R12 and the R134a fittings, you can't mistake them. Electric fans do wear out. Then again, there are two different expansion valves. Its chemical symbol is CCl2F2. You may be just fine on oil - it depends on what compressor you have & how much oil you put in.A T/C is short for Thermocouple. video clubhouse baseball; nick fairley draft profile; ben davis work pants Do a pre-inspection and then Evacuate (vacuum down) the system, the longer the evacuation the better but there is a point of diminishing return, 2-3 hours is generally very good. R-12 - yellow R-134a - light blue R-22 - green R-402A - light brown (sand) R-402B - olive R-404A - orange R-407C - medium brown R-410A - rose R-507 - teal J Originally Posted by goldNSX. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. Unfortunately, the oil only mixes with the refrigerant as a liquid. 37 in 2005 tacoma, R134A. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. B. The oil used in R12 systems is not compatible with R134a refrigerant. ambulance tailgate conversion Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. Use strips of foam to couple the two heat exchangers if necessary.B. This chart has a column of ambient (outside) air temperatures on one side and a corresponding range of high side pressures on the other side. R12 and R22 are both now banned by the EPA in the United States. It slowly gets warmer and warmer in the car, even at highway speeds. In short, NO! However, take note that R134a refrigerants are manufactured specifically for automotive air conditioners. Is checking the temperature of the in and out of the condensor not the easiest way to tell if it is doing a good job or not? R12, on the other hand, is called chlorofluorocarbon (CFC). However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products. There are two hoses listed, R-12 64-53-1-377-821 for $72.50, and R-134a 64-53-8-391-051 fro $262.50. $21 . When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. Rules governing changing from the former to the latter differ between countries. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. Besides, you have a greaseisel. Maybe a jerky locker.I cleaned the condensor with the off the shelf ac cleaner stuff from Home Depot that I used on my home evaporator. R-134a XV for R-134a use. The cost of recharging the air conditioner is between $150 to $500. and he synthesized R-134a in 1936, 5 years after R-12 was . So I probably put the highest suggested amount in to be safe. But some types of PAG do not mix well with the old residual R12 mineral oil left in the system components whereas ester does mix very well. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Trinary Pressure Switch $ 39.99. I think the way to go here is1. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. This may be the source of your oil confusion. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). R12 and R22 are both now banned by the EPA in the United States. It would make a big difference at idle ,in traffic!! For example, at an evap temp of 30 (your daughter's system is probably running around 25-28 saturated in order to give a 32 duct temp), the pressure of R-134a is 26.1psi. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. At least you do not have 16 ounces in there ( yup seen it before).For now, straighten all of the fins that you can, clean the condensor well, and re-test with the aux fan running. Not going to mess up your 'do, but you can feel it. What was the ambient when you took that reading?Jumpering the aux fan is a common thing here in the desert. 30 deg is pretty coldSystems generally run between 40 and 43 deg. The original expansion valves work very well with R134a. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. I used a full can of evap cleaner. And yes - expansion valves sometimes need replacing if they are sticky - but a proper AC flush should eliminate the need for a new one if it's already in good condition. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." The newer valves and switches will work with both refrigerants. It may take a couple of tries to get things really clean.The laser is usually close on clean surfaces, but I prefer a T/C. CR4P). A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues.You could improve the cooling capacity by replacing the condensor with a high effeciency parallel flow unit. He used thermostatic expansion valve and Capillary tube for analysis with R12. It won't be optimal, though. R12 is otherwise called dichlorodifluoromethane is a colorless gas (chlorofluorocarbon halomethane (CPC) that is used as an aerosol spray propellant and a refrigerant, and is soluble in organic solvents. I mean, really a lot. I have some experience with auto a/c but not too much. It is made up of carbon, hydrogen, and fluorine. Add to cart. Biggest you can fit in there is best. by | Jun 21, 2022 | what is the most accurate latin translator | burlington iowa arrests | Jun 21, 2022 | what is the most accurate latin translator | burlington iowa arrests . We ALWAYS want to know the pressure readings! Theres no doubt that R12 refrigerant is one of the first compounds manufactured for the air conditioning and refrigeration world, but it had to be banned. Welcome to rxmechanic.com. Don't like the sound of custom parallel condensor. Its highest value is 1. It cycles on off in med (or low for that matter)Gotta tell ya. Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. Use a drop light in the engine bay, and check the air path from the front of the car at night. Note that passwords are case-sensitive. The crossover point is approximately at 64F. In a car ac, using this type of freon 20 years ago was difficult. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. . I've done the FSM test and with 81F ambient, the vent should be 50F. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. difference between r12 and r134a expansion valve. Also, if you want to know what happens if you put R134a in an R12 system, you should first confirm if the R12 system can be replaced or if the refrigerants can be mixed. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . So the steps involved are cleaning out the old oil, replacing all the O-rings, replacing the dryer, replacing the expansion valve, and converting the high and low side connectors from Schrader to quick connect valves. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. It is usually sold under the brand name, Freon 12. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. R134a requires the use of synthetic oil! This is because R134a. Statisicaly your friend was lucky. (The .133 is the 300D Turbo).So, what does your compressor look like?B. As an example, let's say the R12 charge specification is listed at 2 lbs. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. Compared with the cost-performance ratio, R507 is 30-40% . R134a refrigerant is about 10% less efficient in moving heat than R12! R134a is otherwise called 1,1,1,2 Tetrafluoroethane, Florasol 134a, Freon 134a, Norflurane (INN) or HFC 134a. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . CLUTCH CYCLING SWITCH. Participate in over 40 different forums and search/browse from nearly 3 million posts. Temp switch works the aux fan. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? When the ambient air temps get above 80F the gauge readings can run a bit higher on the high side and lower on the low side when using R134a. One thing at a time here, and slowly, the knee is not up to jumping around like I used to at the moment. How about evacing 1 pound of refrig from the system, and then putting 1 lb of pure R12 back in? If you still find it difficult to use R134a in a home AC system, you can check out a comparison of R12 vs R134a fittings to know the refrigerant that best fits the AC system. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. 5. Pound for pound R134a is a more efficient refrigerant than R12, however it runs at higher pressures in some aspects and therefore requires more effective condensing. Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. R12 was once used in many air conditioning units as a refrigerant or cooling agent. Talk about what services you provide. R134a Refrigerant Recharge Kit with BPV31 Bullet Piercing Valve and R134a Quick Coupler, R134a/R-12/R-22 Freon Refrigerant Hose Can Tap Kit for A/C System - Easy to use. Its cylinders are colored white. In no particular order, here's what I've found out regarding answering the questions posed so far:Fonebone - It is definitely an R4 compressor (they left the c off the front and the p off the end, i.e. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. The car never overheats, if that has any import. The most common influences which effect the capability of R134a to perform well are the condenser, in some cases the the superheat setting of the expansion valve or the amount of R134a. Hmmmm. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 The typical scenario here is when the car owner buys an inexpensive retro-fit kit from the local auto parts store. . Sense ells no existirem. absorb by the evaporator to insure all liquid refrigerant entering the evaporator. The pressure/temperature curves for R-1234yf and R-134a are very similar. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. This works when the R12 charge specification is listed in pounds. The system has been previously converted to R-134a. Then again, there are two different expansion valves. My turn to LOL - greasiesel! 1) Look Here at the available sizes of PF condensors.2) Go look at your vehicle's condensor & mounting. Mine was 61, so the system is not working as it is supposed to. Using R134a requires that Polyolester (POE) lubricant must be used in the compressor. Just leave it alone for now. link to How to cut off a Catalytic Converter. 3 ounces? Thanks so much Bohica - you've save me many more hours of fruitless speculation. For those of you who are considering what the cost is for R12 you can think of it this way: Dont go out to dinner this weekend. Bookmarks: Digg; del . Best for varieties of operating conditions: Its boiling point is -21.6 Celsius. If you find any of these conditions you will want to liquid flush (with dedicated AC flush solution) all the lines, condensers, evaporator (remove the expansion valve) before you proceed further. The non-flammables can have R22 type gas which is not compatible with most rubber hoses or they have gases that contribute to global warming. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? What is a good differential? By: james smith underoath; Comments: 0 . 5. Heres R12 vs. R134a pressure chart. Still, I have some simple green, so may as well give it a go. Pray I can let some oil out of the compressor without losing my precious R12. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. The sticker typically has a place to note the amount of refrigerant used, the type of oil and amount of oil, the technicians sign off or name and the date of the conversion. Swapping the components isnt a herculean task, but recharging the AC is a challenge. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . Break out the new gauges and measure hi and lo at 1500rpm, and do the Merc FSM test to see how we're doing performance wise. And I already have so much time and money in this a/c project that I REFUSE to cut any corners as small as a TEV.It doesn't help that most people in the business (at least that I come in contact with, present company excluded, of course!) Yes, this was a smokers car. Why wait for 200f on the engine coolant to start the fan? R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. If liquid refrigerant were to exit the evaporator. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. Since then, the industry standard has been R134a, which is an efficient replacement. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. The oil used in R12 and R134a are different and not compatible. I'm going to check the condensor is way clean too. R134a vs R12 refrigerant? Also, since R134a uses synthetic oil, it has a low global warming potential, unlike R12 which uses mineral oil which poses a negative environmental impact. The expansion valve(Tx) is in the car at the inlet line to the evaporator with compressors you best get advice from an ac specialist shop as the differences could be the gas that it pumps some systems use R12 and others use R134a or later gas yes R1234yf Freon gas can be replaced by R134a; the newer systems were designed with this in mind so no, there will be no damage to the compressor but some time in . Stay home and grill your own steaks and stir your own martini. If you have the work done, be sure you find a true "A/C" shop that can make up lines. The approval is very legal one, governed by the U.S. EPA. Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. VerticalScope Inc. All Rights Reserved. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. R-12 to R-134a Conversion. This allows the refrigerant in the condenser to be void of oil particles. J.Harris said: Or if you want to do it like they do in Mexico you can use propane, it's an excellent refrigerant but highly flammable. Or is there always room for improvement, the more the merrier. By using a qualified a/c shop with the proper equipment you odds are in your favor of having the job done correctly the first time. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. How an A/C Expansion Valve Works. It is made up of carbon, hydrogen, and fluorine. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. The safe high side pressures are determined with a PT (pressures and temperatures) chart. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. R134a is called tetrafluoroethane (HFC). Compatible with multiple applications: The major reason for the introduction of R134a was to replace R12, so it functions perfectly in the same range of applications like rotary, screw, and centrifugal compressors for air conditioning and refrigeration. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. Usually, mechanics charge around $200 for conversion. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." We suggest dumping the old refrigerant oil in a clean container and inspect the oil for sludge or waxing (old oil that has gelled) and contamination (metal particles). I've got a ball valve I'm going to put in the coolant line before the coolant goes through the firewall to the core. Questions About Becoming A Professional Member? To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. Is there more info needed?THanks -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Paul:I had to dig a bit deeper - MB made several running changes in the 1983 123'sThere are actually 4 different circuit diagrams for the A/C system that year - just for your 123.123 I found the R4 reference, and it should have 170 Ml of oil in the system.Your aux fan should run at the ambients you listed. (On firewall where A/C lines go into cab.) How dumb!I will jumper the aux fan and redo the test. If the charge is low the compressor will cycle on/off in the max AC position. Before landing on the debate of R134 vs R12 you should know that both R134a and R12 are AC refrigerants types used in refrigeration and air conditioning systems. Given two identical vehicles, each with the same weighted amount of refrigerant, the vehicle with the R134a has the capability to remove more heat (measured in btus) from the vehicle than the same type of vehicle using the same amount of R12. Please enter the name by which you would like to log-in and be known on this site. A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. The mechanical fan & clutch should be checked as well. But I've read that these car's didn't do too well in the a/c stakes, so that might just be as good as it gets. . The problem with these so called drop in replacements is that to properly handle them you may need dedicated equipment to identify the gas and evacuate it for proper disposal. The pressure at low temperatures is nearly the same between 12 and 134a. Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used. The pressure at low temperatures is nearly the same between 12 and 134a. The catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. El maig de 2016, un grup damics van crear un lloc web deOne Piece amb lobjectiu doferir la srie doblada en catal de forma gratuta i crear una comunitat que inclogus informaci, notcies i ms. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. The Wikipedia explanation for expansions valves cited in Frank's thread says that the gas inside the bulb in the metering valve is the same as the refrigerant in the system. Stopleak is also risky. In practice this means that the car can overheat and the aux fan will stay off! A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. R134a and water have the same abilities to change the state but R134a can do this more rapidly and at a much lower temperature than water. Bottom line, R134a simply doesn't cool as well as R12. By noting the ambient temperature you can look up what the preferred high side pressure should be. B. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. Very interesting! Figure 2 shows the different phases and pressures the refrigerant . But I don't want to waste your time. Your decision could be made based on economics, environmental concerns, or both. The global warming potential of R134a is 1430. Do I leave the orignal condensor in, etc?Thanks. Are you sure you have an R4? and feeds it through an expansion valve. Please enter a valid email address for yourself. Since you will be using less R134a than R12 you do not want to rely on the driers site glass to determine if the system is full. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. The difference between R12 and r134a is the BTU carrying capability. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. Also called the orifice tube. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. Paul:It is never a waste of my time to chat with someone that understands the problem, and wants to fix it. By using a black light the dye will glow in areas where oil leaks are visible. R12 is heavier than R134a and has smaller molecules. With tube & fin condensors in MVAC applications there is never "too much" airflow. Is there a difference between a R134a expansion valve and an R12 TXV? 5. Remove the old mineral oil from the compressor by turning it upside down, side to side, and turn the front hub on the clutch assembly. hardly noticable. Production of R12 ceased in 1996, although it can still be reclaimed, purified, and resold, and small cans of New Old Stock R12 are still widely available on eBay and Craigslist. If you're getting a R134a compressor, might as well finish the job - replace the receiver/dryer, flush everything else, and convert to R134a anyhow. Took me a while to figure that one out, and how to say that. Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. The major reason for the replacement of R12 with R134a was to curb future greenhouse effects. All fans must work at 100% of the OEM rating. The R134a compressor has a 1/8" step in on the high side port. Its chemical symbol is CCl2F2. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." That would be the "black death" syndrome. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! gital control scheme. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature.