This is not to say that one of these small retro-fit kits cant be used, however to be used wisely. Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. 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. The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. Catalog E-1, Thermostatic & Automatic Expansion Valves / Page 1 Table of Contents . I found that in the..Maxposition on the control it will have the compressor running all the time. The system has been previously converted to R-134a. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. It is made up of carbon, hydrogen, and fluorine. 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. Its chemical symbol is CH2FCF3. Read on for more information about using automotive r134a in a refrigerator and vice versa. R134a refrigerant fittings are different size. I'm just trying to help you avoid headaches in the long run. What is needed? GWP is a measurement of Greenhouse Gases and their effect on Global Warming. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. ESP when a compressor has frozen. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. AFAIK, there is no clutch on the engine fan on the 240D. The difference between the two is about 10,000 btu/h. B. Recomanem consultar les pgines web de Xarxa Catal per veure tota la nostra oferta. You can buy bulk hose, and the proper fittings, then have them crimped off the vehicle.Be sure that no air bypasses the new condensor on the way to the radiator. in /nfs/c05/h04/mnt/113983/domains/toragrafix.com/html/wp-content . 4) Inconsistent Airflow. The value of carbon dioxide is 1. 2001-2023 Griffiths Technical Inc. All Rights Reserved. Any advice appreciated. 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. Is there a source of valves by, say, eaton number? $21 . You can spend long evenings reading about the differences between the two refrigerants. 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. The only difference I can imagine would be the recharge connection. (The .133 is the 300D Turbo).So, what does your compressor look like?B. B. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. This is an electronic tool that sucks in air through a tube and across a sensor. Make sure to get the R12 EXP valve if that is the way you go. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. Usually, mechanics charge around $200 for conversion. Stay home and grill your own steaks and stir your own martini. What is the refrigerant property involved that has caused this? 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. 1) Warm Air From Vents. However, it was found to be a very bad gas for the environment. Figure 2 shows the different phases and pressures the refrigerant . -------------------------"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." These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. You will be fine with a 134a-compatible TXV running R12. The system will be checked for gross leaks while under vacuum. Your average garage that works on a/c on the side probably would not have this. #4. Yep, definately not a meat locker. This is because R134a. 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. 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. These efforts to balance the system can not be realized if there are problems within the a/c system, such as: poor performing compressor, dirty condenser or poor air flow through the condenser, malfunctioning expansion valve, water or air in the system, improperly operating fresh air or heat input in the climate-air mixing system. Hmmmm. 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. I'm not sure. On this website we are addressing only R134a and not other suggested drop in replacements. Its chemical symbol is CH2FCF3. If your a/c system is empty/low on refrigerant, if your system has a leak or if you need to open the system, then now is the time to decide which refrigerant you want to use. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. -The amount of R-134a needed will typically be 80-90% of the R-12 charge. We sometimes use a relay switched from the compressor clutch to run fans. Trinary Pressure Switch quantity. Edited: Sat July 14, 2007 at 10:22 PM by fonebone. 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. 4.R404A R134a increased mass transfer resistance to reduce the transmission chamber heat coefficient, while R507 heat transfer coefficient is higher than R404A. Mark Baker R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. Safe but sorry! 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. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. 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. It won't be optimal, though. I used a full can of evap cleaner. 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. I don't recall all the details, but starts off with the largest parallel flow condenser and improved fans. R134a is called tetrafluoroethane (HFC). 3 ounces? R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. The Main change in the system is the expansion valve. R12 was once used in many air conditioning units as a refrigerant or cooling agent. R12, on the other hand, has an ozone depletion potential of 1, implying that it can damage the ozone layer. 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. Sense ells no existirem. So that indicates it is cooling well there doesn't it? Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. Replied by Rich928 on topic R12 or R134a. If the charge is low the compressor will cycle on/off in the max AC position. The global warming potential of R134a is 1430. Please enter a password for your user account. 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!) The old compressor used R12 and the new unit will be R134a. Most vehicles manufactured before 1993 have the R12 A/C system. The MB chart shows 360 psi with R12 in some conditions. Yes, I don't trust the heater valve either. Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. Shorting the plug for the refrigerant switch should run the fan when the compressor is on. At 40, it is 35psi, which is a difference of 8.9psi. Crap! This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. They might say for instance, add 3-4 oz of oil to the compressor, 1 oz of oil for when you replace a drier, 2 oz oil for the evaporator and so on. Existing technology: R134a has been in use in the refrigeration industry for very many years, and theres so much information about the safe use of the product. Instead of using R12, its preferable to use R134a because it is very easy to find in the market, its sold at an affordable price, and is environmentally friendly. . However, the supply houses don't indicate a difference. . If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. 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. Electric fans do wear out. 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. In 1994 they switched from R-12 to R-134a. And by matching the correct amount of R134a to use in a given vehicle, correcting the superheat of the expansion valve (if necessary), you can in some manner nearly balance or match the amount of heat drawn out by the evaporator and released by the condenser. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. I put in a new (not reman) compressor (R4 I believe it is) in my merc 240D, new drier, new expansion valve, new o-rings, nylog. Then again, there are two different expansion valves. difference between r12 and r134a expansion valve. Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. In more serious, it could result in cardiac irregularities or death. . The crossover point is approximately at 64F. For R12, its mineral oil. . The P H and T cond,sat of the HR12 at a T oa of 40 C were higher than that of the R134a, resulting in a higher P e than that for the R134a. Fitting a PF condensor is not rocket science, but it requires some planning. The oil used in R12 systems is not compatible with R134a refrigerant. Just had knee surgery yesterday, so I"M not exactly hopping around too well. This would be a custom install, there is no "drop-in" condensor upgrade for that car.Check for proper fan operation, and clean the air path on both the condensor & radiator. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. 34 in 70 series w/ R12 in 100+ Tucson, AZ summer heat w/ hd-t, w/ 13B-T is was unbearable about 31 at vent w/ R12. |. How is 1234yf different from . Then again, there are two different expansion valves. 5. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. 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. If it splashes inside the eye, it could lead to a serious eye problem. Using R134a requires that Polyolester (POE) lubricant must be used in the compressor. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. 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. Lasers don't do well on vent temps, a stick thermometer is better in that application. absorb by the evaporator to insure all liquid refrigerant entering the evaporator. Then at least I'd know really where I am on it. Why wait for 200f on the engine coolant to start the fan? It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. Just because the radiator does not boil people assume that the cooling system is ok. look at the difference! Super heats are so close, it should not be a major concern.-------------------------The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government. Are r12 and r134 fittings different? I could easily be over at least 2 - 3 ounces over on the oil. A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger.