pressure test air conditioning system car

We've updated our forums!Click here to visit the new forum, I wanted to test my car's r-134a system for a leak using compressed nitrogen. The filter drier should be replaced each and every time the air-conditioning system is opened up to the atmosphere. Chevy Corvette Perfect Fit Air Conditioning System Updated April 2014, Air Conditioning Upgrades for Mopar B Body Cars 1968 1970, Connecting a Serpentine Belt System to Factory Air in a 1970 Chevrolet C-10, Weird Winter Tip to Keep Your Cars A/C Compressor from Springing a Leak, Typical Problems Encountered In Charging The A/C Kit, 1970-72 Chevy El Camino Smart Series kit. Look up the test procedure in service publications. The A/C system is tasked with transferring heat energy out of the hot cabin and out to the atmosphere. Are the service port caps on and tight? The exception to that is a recovery mechanism that is only used to recover contaminated refrigerant. This missing cap represents a leak of about one-quarter pound of refrigerant a year. As you probably know, when the ambient temperature is below 32 degrees the system won't turn on. Go to a licensed professional. If you evacuate for 30-45 minutes, the filter-drier should handle any residual moisture without a problem. The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network. If there is vacuum loss of 2 or greater, there is probably a leak. The gods here say not to go over 150psi. Not only could you damage the system you can severely injur yourself to include death. Another benefit of air removal when can charging is that it eases the initial charge of refrigerant into the system. https://www.facebook.com/AutoBodyRepairNetwork/, https://www.instagram.com/ptenmagazine/?hl=en, https://www.linkedin.com/company/40735491/, https://www.youtube.com/channel/UCxBEkpoYgmG0r34_B3mOr4Q. Initial leak check 2. I have heard of 250 PSI damaging low side components (evaporator) but maybe it was already on its way out. Swab the suspected area with the solution. We use cookies to optimize our website and our service. 2) Connect the cylinder of OFN to a service connector, component or line, using a suitable adapter. Once charged, you can listen or soap test for leaks. Instead they are evacuated using a vacuum pump. Let's get back to how to test the A/C system of that car sitting in your stall regardless of the month and ambient conditions: 1. You will also want to have a refrigerant identifier, leak detector, and sealant detector that you use before connecting your gauges to the vehicle (Figures 1, 2). Figure 1 - This type of machine is required by the EPA for each type of refrigerant that you service in your shop. As a Ford trainer and as faculty in Ferris State University's Automotive Program, I often had to teach A/C classes in November, December, January, February and March in Michigan. 6. Let's start by answering just the first question. I mentioned that sensors that can cause problems. The real question is: "How do you test an A/C system?" Figure 2 - Examples of tools needed to test the AC system. It is often quite cold in those months, yet I never had difficulty in teaching this subject for those techs and students. Battery state of charge conditions is within normal parameters. Autodata OnlineAll information used in this article is taken from the Technical Topics section of Autodatas Online 3. (Figures 3a, 3b). I'll report back to let you know how it goes.. Figure 8 - This 2005 Ford Explorer is ready for a performance test. I would like to keep the system original. Repairify outlines key topics for mechanics, How to take electrical measurements on EVs, Different battery types and how to care for them, How to avoid premature drive system failure. Figure 7 - A necessary tool for system analysis is a scan tool. Connect a scan tool and see if there are any DTCs from the HVAC system or PCM that may be keeping the system from operating. 5. If the source of the refrigerant leak cannot be found through visual inspection, there are various other methods available. I used argon from my TIG setup instead. Evaluating the performance of an air conditioning system is not a difficult task, especially when in the hotter climates. After 30-45 minutes of evacuation, close the service valves and turn off the pump. As a Ford trainer and a college teacher teaching A/C systems, how could I teach A/C diagnosis? The highlighting effect produced by exposure to the light of an ultraviolet lamp makes it easy to locate refrigerant system leaks. Figure 5 - There are choices for identifiers, this one is showing that the system has 100% R-134a in it. Prepping the vehicle is critical to being able to test and use the test results to analyze possible concerns (Figure 8). Powered by UBB.threads PHP Forum Software 7.7.1. This can and does happen. Another vote for a vac test (although a system that will hold. A case in point is our in-dash air conditioning and heater We recently heard from a customer interested in having his original 71 Pontiac LeMans evaporator unit with POA valve rebuilt & restored and set up for 134a. To summarize proper AC system evacuation: -Dont do it if you are not a licensed professional -New filter drier -Evacuate for 30-45 minutes at 28-30 Hg -Let the AC system sit for 10 minutes. If you are not EPA certified 608 and 609 at a minimum you should not attemp to service the system. Under vacuum, the seals or O-rings will move in one direction and under pressure they will move in the other direction. You may be able to check for leaks, but even in Death Valley youre not getting out much moisture. At first, everything was fine. IMPORTANT: DO NOT exceed the recommended pressures (use a pressure regulator) and DO NOT operate the air conditioning system with oxygen free nitrogen (OFN) in the refrigerant circuit. Moisture wont be drawn out by the vacuum pump unless it boils. Evacuation Purpose #1: Initial Leak Check If everything is in order when you evacuate an AC system, the low side should reach a minimum of 28-30 Hg within a short period. . Since refrigerant is heavier than air, spend additional time on the under-side of components. Those sniffers are very senitive and the tip can be ruined/tainted real easy. The bubble test method is a cheap form of leak testing and can assist in finding a variety of leaks, but it is not as reliable as other leak testing methods. The real question to answer is not: "How do you test in December?" When a refrigerant leak is detected, the tester will emit an acoustic signal. Wires disconnected? Testing1) If the air conditioning system is still operational, recover the refrigerant. Classic Auto Air has been using the latest technology to create high performance model specific A/C kits for your 1940s-1980s vehicles since 1977. The signal and intensity will change as the concentration of refrigerant gas increases or decreases. On this vehicle there is communication across three networks and between four ECUs, just to turn the compressor on! 910 Freeport Parkway, Suite 100 Coppell, TX 75019 |. The ambient temp sensor was close to the radiator and not in a position to have outside air blowing over it while parked. You may use a factory tool like this Ford IDS, or any number of aftermarket tools that can reprogram and test using bi-directional control. Another typical operating characteristic is that when placed in defrost mode the HVAC system will usually engage the compressor even when the temperature setting is calling for heat. Figure 6 - This gauge set has been connected to a system that has not in operation. You will want to investigate the availability and efficacy of those items. If the leak cannot be detected with the air conditioning system switched off, start the engine and operate the system to build up system pressure. This also means that your equipment may not be able to connect to the system. Pressure equalization is what happens to the operating high and low side pressures (they equalize) when the system is shut off. One of our favorite Go-to-a-licensed-professional-for-AC-system-charging stories involves a guy we spent more time than we care to admit troubleshooting before it became apparent that he was releasing the vacuum before charging. New Filter Drier Note If your evacuation is done as part of a new system install, youll have already installed a new filter drier but if it is part of a system repair, dont forget to replace the old filter drier. . Ensure the refrigerant circuit is fully charged. Note, running it longer than 30-45 minutes will likely remove even more moisture but you reach a point of diminishing returns. Following the manufacturers instructions add the amount of dye stated to the refrigerant system. Based on the tables determines if the refrigerant system is working as designed. Commercial installers of our kits as well as professional, licensed air conditioning repair facilities have asked, so we have developed a six-point checklist Customers often ask whether or not they need to add oil to an air conditioning compressor they purchase from us. As with any article or other automotive technical training, there is no perfect, works every time it's tried method of repairing cars. Engine torque conditions are within normal parameters. I looked down at the controls and noticed that the outside air temp was reading was 110 degrees. If vacuum loss is less than 2 Hg, Youre ready to charge. If an air conditioning system requires frequent charging, a leak test should be carriedout. All according the Ford service manual. That's my suggestion. One of the first cars I owned with automatic temperature control was a Pontiac Bonneville SSE. Preparation for leak testingThe refrigerant circuit must be under pressure when performing a leak test. Remove moisture. Ensure that the air conditioning system is charged, a partial charge, approximately 225g is sufficient. Why 30-45 minutes? Would I be able to pressurize the low side in one test, then the high side in a separate test (checking for leaks each time) or should I pressurize the system from the low side only?I've read somewhere when doing this test the low and high sides should be pressurized simultaneously each with their respective pressure values (lower pressure on low side and higher on high side), but I don't think I could create two seperate pressures in the system at once with the gear I haveAny thoughts?Edited: Wed July 16, 2014 at 11:56 PM by seagull369. Check for bubbles which would indicate a leak. As a technician who spent his career in Michigan, I can say that we did very little A/C work in December. Compare your results to the tables in the service manual (Figure 9). Last month we covered charging stations. You cannot fix that car without access to service publications and a scan tool and/or J2534 pass through. -After charging, electronic leak test. You can then charge nitrogen into either the high side or low side regulated at 100 to 200 PSI (150 would be my preference). Go to a licensed professional. Evaporator temperature is above approximately 1C (33.8F). 2022 Endeavor Business Media, LLC. Electronic controls and the possible concerns that may be caused by skewed sensors, faulty programming, and drivability issues are each worth their own articles. Compressor, lines, receiver-dryer or accumulator, heat exchangers. My mechanic says I need to replace my AC filter drier. We'll get to it shortly. Our customer didnt get this. Do I Need To Add Oil To My AC Compressor? If no sealant is found, connect an identifier and check for what refrigerant and other possible contaminants may be in the system (Figure 5). I digress, back to Step 8; the performance test is designed to find refrigeration system concerns and is based on the reality that for any given temperature and humidity level a properly charged, correctly operating system will have defined pressure readings. By now I am sure that most of you have figured out the answer to the question of testing in cold weather. Areas to checka) All connections and pipesb) Compressor drive shaftc) Compressor service valves and sealing gasketsd) Condenser and evaporator matrix tube endse) Receiver/drier or accumulator/drier connectionsf) Pressure switchesg) Spring lock coupling connectionsh) Hoses. As long as you have been 609 certified you may legally work on R-12, R-134a, EPA SNAP refrigerants and R-1234yf for consideration. Remove air 3. The high or high pressure side is from the compressor to the expansion valve. Again, if you are asking this question, our response is the sameyou shouldnt be charging the system. Follow the OEs service procedure, be ready to fix seemingly unrelated concerns, and for refrigerant concerns, rely on the performance test. Leak testing using an electronic testerElectronic leak detectors can be particularly useful in finding very small leaks. I would simulate airflow issues by placing obstructions in between the condenser and radiator, faults in cooling fans, even faults in engine sensors for them to find. I have never seen an AC system pressure tested. Vacuumed for a half hour then let it sit for another half, and it held (not sure if it was necessary to do that latter step since it didn't leak under pressure, but figured it wouldn't hurt). The EPA has indeed identified certain refrigerants that you may use in place of R-12 or R-134a, these are SNAP refrigerants, Significant New Alternative Policy. My caveat to, will this work every time? When you have high-temperature extremes, you may have trouble reproducing a concern. The EPA is requesting that techs re-certify for R-1234yf but are not requiring it at this point. (Direct Electric Replacement ) controls, we have received loads of requests Later in the month of April, I'm heading to New York City to see two icons brought together who haven't met in decades. Leak testing using oxygen free nitrogen (OFN)Nitrogen has a molecular structure which makes it suitable to find most leaks, and in addition it is reasonably priced. If you found that the system contains two or more refrigerants, consider it to be contaminated. POA - an abbreviation for Pilot Operated Absolute - valves are Well, we've done it again! We'll get to it shortly. How do you test an A/C system, in December? That way, what I say will make sense to all. The dye can be added to the refrigerant system during repair, or during the evacuation process, depending on the equipment available. Always make sure the caps are on and secure. The leak will be visible when the dye is exposed to the ultraviolet lamp. As you work on vehicles (and I cannot emphasize enough), the importance of understanding how the system works, and using service publications to direct your steps as you analyze whether or not the system is working like it is designed, is extremely high. After about 10 minutes I noticed the air blowing out was getting colder and colder, and I heard the A/C clutch engage. You would be better off pressure testing the system as well as vacuum testing. You can trust these charts if you've done the performance test as required by the OE in service publications. You can breathe on it and set it off. It is showing that ambient temperature is ~70 degrees and the refrigerant pressure is `70psi. Factory original purists may balk, but sometimes original dashboard designs can be improved upon. Want to start the conversation? The initial starting point for this test was the band at 2.4 on the scale. Start the engine and operate the air conditioning system. I always like to baseline my training so everyone is on the same foundation. This is one of those procedures, based on my training and my experience that works nearly every time it is tried. How could I know the techs/students had learned how to test the system and be confident that the techniques would work when called upon, when evaluating A/C in the winter? http://www.ackits.com/index.php?route=product/product&product_id=31708&search=big+blu-------------------------, I found the leak in a hose leading to (or away from) the compressor. How do you test the A/C system in your shop in December, in Michigan or anywhere else it's winter and cold? No comments have been added yet. Give me a minute to finish the process and I'll explain the differences for cold-weather testing. A frantic call to the service department and the first available appointment later and I was doing A/C work. The way you test an A/C system in December is the same way you test the A/C system in every other month of the year: by the book. 3. Modifying those vehicles A/C systems may fall under emissions tampering. Dry nitrogen is the way to test with a true pressure of what the system would run. Pass the probe under the suspected leak area starting at the highest point in the circuit (refrigerant gas is heavier than air). Its worth it to get it done right. Ford introduced the Flex in the late Summer of 2008. A good visual inspection can find many problems. 10 to 15 bar (sufficient for leak testing purposes), and close the valve. 5) Release the OFN from the circuit before attempting any repairs. No, I'm not talking about seeing Rocky meet up with Apollo Can aftermarket air conditioning components improve on OEM design? Please, if you are not a licensed AC professional, do not evacuate/charge on your own. Can you open the can, replace the filter and dessicant and weld it up again. Here's one example of the types We've been working on classic cars for several decades now, so we've got a good picture of the quality of thousands of different parts made by scores of manufacturers.

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