Auto Service World
Feature   April 1, 2011   by Nestor Gula

Giving Summer the Cold Shoulder

Making A/C service once more part of the regular maintenance schedule

Most vehicles sold these days come equipped with an air conditioning system installed. Whether it is to deal with the hot weather — while this may be Canada, it does get very hot here in the summers — or simply to boost the resale value of the car, the air conditioning option is one of the most popular on today’s vehicles.
With so many A/C equipped cars on the road and the hot weather around the corner this should spell an increase in work for most shops that perform A/C work. Many car owners neglect the air conditioning system and only come in when it has stopped blowing cold. Many service shops also do not include A/C diagnostics in their annual maintenance schedule.
“The typical A/C systems found on today’s vehicles are certainly much more ‘tight’ than they were even just a few years ago, and refrigerant loss simply through normal use has been significantly reduced,” said Tim Stumpff, group product manager with the Bosch Diagnostics Business Unit. “Even so, with today’s smaller refrigerant capacities, losses over a two-three year timeframe can deteriorate A/C performance — which impacts not only passenger comfort, but also fuel economy.
“Since A/C performance degrades slowly over time, most consumers do not notice the change until the system virtually shuts down or becomes inoperative. This is clearly an opportunity for shops to take a proactive approach to servicing.”
When a customer comes in with concern about the air conditioning in the vehicle it is important not to jump to conclusions.
“Someone comes in and says, ‘Hey my car is not blowing cold,’ you automatically suspect that there is a leak somewhere,” said Chris ­Bahlman the director, service operations at ­Delphi Product & Service Solutions. “You run some dye in it and maybe find one leak, but if there is more than one…” He said a proper diagnosis has to be done each time.
“We prefer that you do not do any invasive checks; that means hooking up equipment to an A/C system, unless there is a complaint of some kind. Another way of looking at is you would only start looking at an air conditioning unit when it is not cooling properly,” said Paul DeGuiseppi, manager of Service Training for MACS (Mobile Air Conditioning Society). This organization is the leading non-profit trade association for the mobile air conditioning, heating and engine cooling system segment of the automotive aftermarket.
“You can measure inlet and outlet temperature of the condenser. You can measure the inlet and outlet temperature of the evaporator, with a good contact thermometer and that will often give you a good idea of the state of charge in the system. The temperature readings will give you a good clue that there is a low charge.”
Read the manual
DeGuiseppi said that a properly trained staff is paramount to running a proper diagnosis and service of air conditioning of cars. He also notes that even with proper training obvious mistakes are made.
“This might sound simple but it is true. The techs, don’t read the instructions properly. That is why they don’t use the equipment properly. It is very simple. The manufacturer knows how to use that machine better than you do, so read the instructions. I see this all the time.”
“You should be doing just basic diagnosis that makes sure that the system operates the way that it should,” said Delphi’s Bahlman. “Instead of just assuming that if there is a problem with the A/C unit than it has to be a leak.” Other problems when servicing air conditioning systems are sloppy and imprecise work.
“Inadequate flushing. Once it is determined that there is a leak, you have to evacuate the system completely. Every time a system is serviced or anytime components are taken apart, there has to be a pretty thorough flushing of the system. Dyes must be specifically designed for that air conditioning system — you cannot interchange them,” Bahlman stressed. “The dye has to be used in a one shot deal. It has to come from a sealed container. In that the dosage is proper. Not enough is not enough and too much can definitely be harmful.”
Bahlman said that properly understanding the system that is being serviced and reading all the literature associated with it is very important. “Some component manufacturers do not recommend the use of dyes because they don’t want it floating around their condensers or evaporators,” he said. “The tech must really be careful to note any restrictions on the use of them in the system.”
What you need in your shop
A great concern for those that service air conditioning units in vehicles is the industry’s move to a new refrigerant standard. Goodbye R-134a and hello to R-1234yf — right? Well, not right now.
“You will have to have separate equipment to work on the new refrigerants,” said DeGuiseppi. “(But) if you need tools and equipment right now, buy what you need to work on R-134a. Don’t even think about the new stuff. Buy what is currently available, seriously. When that stuff comes around, you will need to buy a separate machine anyways. These cars with the new stuff are going to be coming in drips and trickles. There are millions of cars that use the older R-134a standard and are on the road now. This is what most, if not all, of the shops will be working on for many, many years.”
When buying equipment, he cautions to buy reputed brands and from reputed dealers. “It’s as simple as this, whenever you are buying equipment to work on AC systems buy the equipment that meets the SAE specification. That’s the best advice that I have. I’m talking about the recovery machines, the dyes and leak detectors. The most commonly used tools must meet the SAE standard.”
There is a great deal of choice in air conditioning service equipment. According to Bahlman, “The machines all operate fairly the same, some require a lot of input from the tech others are fairly automatic. With some systems you just hook up the vehicle, you punch in what the vehicle is and you literally just walk away. It will pull the vacuum, it will recharge to the exact amount of recharge and some of the machines will actually do the oil inject at the same time.”
What you do need to know about the new refrigerant standards
“First of all, the material itself, R-1234yf — the actual refrigerant — is more flammable compared to R-134a,” said Bahlman. “What that will mean, is that the shop must absolutely make sure that the materials are handled with care. So what they will have to use is use vessels and storage tanks that exactly meet all the regulations and the shops will not accept anything that looks like it was recycled or reused when transferring the material. The shop will have to make sure that they are buying from a reputable supplier.”
The fact that the R-1234yf is flammable should be a concern. “It is more volatile, but it does have a very high flashpoint so it takes a lot of ignition energy to make it burn,” he said. “So the procedures in the shop are still no smoking, no open flames, keep it away from sources of high heat, and stuff like that.”
“The material is effectively a derivative of the existing R-134a in that it is not necessarily a brand new compound. It was designed primarily to function in existing systems in terms of the architecture system. So unlike R-744, unlike CO2, it is not a refrigerant that requires extremely high pressures to operate, like the CO2 type systems that they are still talking about in Europe. This does not drive massive changes into the architecture or the basic service procedures,” said Bahlman. “The tech will still have to do the same basic diagnostic from checking the temperature of the air com
ing out of the cabin vents to ultimately leak detection.
“The standard of the leak detections, in conjunction with this new material, is SAE 2791. There are some new leak detectors on the market that are better at picking up the leaks, they eliminate false positives which will see the industry pushing the electronic leak detectors as a standard.”
Tony Ferraro, president of Uview Inc. is confident that his dyes will match the new standard. “We have product and the dye works with the new specs. So there is no change in the procedure or the equipment on our end.”
He said different hoses and fittings would be needed. “We have already done some testing with our trace dyes. They should work fine in R-1234yf systems. As for our electronic leak detectors, new software will be required to detect R-1234yf leaks,” said Bob Savasta, marketing communications manager for Spectronics/Tracer Products. “Newer vehicles have tighter systems, mainly because of better O-rings and seals.
“I expect R-1234yf systems to be even tighter. Aside from keeping the condenser clean and changing drive belts when they’re worn, there is not a lot of maintenance necessary for A/C systems. Of course, adding a trace dye never hurts, because you can locate leaks very early on, long before the customer will notice a change in cooling performance,” he said.
“We believe we will see its first use in Europe late this year if everything stays on track, and we should see some limited application in the North American market with the 2013 model year,” said Stumpff from the Bosch Diagnostics Business Unit. “But it’s probable that it will be at least two-three years before these systems will hit most repair shops. Collision shops and dealers will probably see the new refrigerant first, and then aftermarket service facilities will get them.”
Bahlamn said that, “all of the requirements are actually coming together now, so we are actually on the edge of it in North America — it is not completely defined yet. This new standard will be able to detect down to fractions of a gram per year,” he said. “It is an extraordinary tight standard. In fact, the standards are so tight that the typical dyes that they put in the systems will run the risk of contaminating components. Some OEM manufacturers in Europe do not recommend using dye with the new technology.”
What the technician has to understand is that the basics of the air conditioning unit will not have changed much, unlike those on hybrid and electric cars. “It is not deriving any major changes in the architecture in terms of how the system works. However, vehicles will not be able to be retrofitted,” said Bahlman. “The position of the European OEMs is that if you have a vehicle that was manufactured with R-134a in the system, then you must use that refrigerant.
“The reason why, is that they are anticipating a massive reduction in efficiency if you were to put R-1234yf into an R-134a system. They, the manufacturers, have not gone into any specifics about any damage to seals or components. This is something that is coming down and as a supplier we are coming up with our standards now.”
Due to the similarities in the systems, the machines that service them will be familiar.
“If a technician is looking at a recovery machine, the recovery machine itself will be similar with what you have that ran with R-134a,” said Bahlman. “There are machines being developed in Europe that will be able to handle both R-134a and R-1234yf. It would actually have an automatic purging circuit in the machine. So if a tech did a R-134a vehicle, presses a button, there is a self cleaning circuit that flushes all the hoses, lines and fittings from the machine then he would be able to switch vessels and service a car with R-1234yf.”
Should you, as a technician or as a shop manager start switching over to the R-1234yf standard? Not really. For one, “the refrigerant itself is in short supply,” according to Bahlman. The first cars might show up on showroom floors no earlier than 2013.
“When you look at the OEMs, they are going to continue manufacturing vehicles that use R-134a refrigerant through to 2017,” he said. “So there is a long grandfather period where we will have both systems on the market at the same time. The 2017 is a European standard right now but might become a global standard eventually.”
R-134a equipped cars will be manufactured for at least another six years and will be the predominant vehicle on the road for at least the next 15 to 20 years.
This is just like with any niggling problems on vehicles. Should you worry about R-1234yf? No. Should you monitor the situation and keep yourself abreast of all developments? Yes.

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