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MACS 2019 Mobile A/C update

Wednesday, May 1, 2019 - 06:00
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Compressor clutch failures topped the “Reason for Service” list, followed by leaking service ports, line connections, hose crimps, compressor (case or shaft seal), condenser, evaporator, drier, expansion device and finally, switches (Figure 4). Not surprisingly, the most common yf component to be replaced were condensers, as they’re front and center to ram air and all the road dirt, debris, salt and (in the northeast) winter brine solution that loves to rot them out.

Figure 4 - (Courtesy of Ward Atkinson) We asked shops to tell us their Top 10 Reasons for A/C System Service, broken down by which refrigerant they were working with. Failed compressor clutches topped the list for R-134a, but it was condensers that failed most often with yf. Considering that most aftermarket service on yf systems is for accident repair, this comes as no surprise.

Ward Atkinson, MACS technical advisor, presented this year’s survey data, explaining that since MACS started these field surveys back in 1990, “We’re not seeing the same type of internal mechanical compressor failures anymore like we used to, and that’s because of today’s tighter, lower charge systems. They’re being made to keep the lubricant inside the compressor, and not circulated around in the system.” This means that even as refrigerant slowly leaks out over time, it’s not carrying as much oil with it, and although this leads to eventual performance issues (and the need for service), more compressors are hanging on to cool another day.

We’d bet most shops don’t like to admit to this, but inadequate diagnosis was called out by more than 80 respondents, indicating that a closer look may have been warranted in at least some of those cases. Shops reported most often that a second leak had been found (or maybe it was the original leak that was missed the first time), followed by defective replacement parts and secondary failures.

Another interesting point was learned when we asked which leak detection method do you use, and more importantly, which do you prefer. MACS members use electronic detectors more often, but both groups prefer to use trace dye when possible. This makes sense too, because especially if dye is added by the factory, it should be present at most leak sites by the time it shows up in our bays. Except for those few locations where dye generally cannot be found in an A/C system, the intuitive nature of dye is what makes it so useful. If you see it, there must be a leak, and if you can see where it’s coming from, you know what to repair.

Sealants also continue to be somewhat of a problem with people not wanting to work on exposed systems, although we did find that member shops are more willing to take on the challenge. That likely has to do with a shop’s level of expertise, but we don’t blame those who pass up the chance. One false move and you “own it”, including the potential damage to your shop’s equipment.

Figure 5 - (Courtesy of Ward Atkinson) System flushing is performed by most A/C repair shops, although some won’t take a chance, and prefer to only replace parts. Still most will at least try to flush simple items like lines and hoses, but not more complex items like condensers, evaporators, driers, TXVs, mufflers, and certainly not compressors.

Flushing is a very interesting subject, and whether or not you can flush dirt and debris versus just oil is a big question that often sparks debate. As most people are beginning to identify, you’re probably not going to get most of the big chunks out, but if the little particles can be suspended in liquid, there’s a better chance with them. There’s also the issue if you can even get most of the flush solvent back out of the system, which is a big question particularly for the OEs. Their concern is that any solvent not removed can remain in the system, diluting the oil and reducing its lubrication capability for the compressor. See Figure 5.

A list of models (by OE) that have switched over to R-1234yf
  • Acura: ILX, MDX, RDX
  • Alfa Romeo: Giulia, Stelvio
  • Audi: A4, Q5
  • BMW: All U.S. Models
  • Buick: Enclave, LaCrosse, Regal
  • Cadillac: All U.S. Models
  • Chevrolet: Bolt, Camaro, Colorado, Cruze, Equinox, Impala, Malibu, Silverado 1500, Spark, Suburban, Tahoe, Traverse
  • Chrysler: All U.S. Models
  • Dodge: All U.S. Models
  • Fiat: 500, 500L, 500X
  • Ford: Edge, Escape, Expedition, F-150, Focus, Fusion, Mustang, Ranger, Transit Connect
  • Genesis: All U.S. Models
  • GMC: Acadia, Canyon, Sierra 1500, Terrain, Yukon
  • Honda: Accord, Civic, Clarity, CR-V, HR-V, Insight, Odyssey, Passport, Pilot, Ridgeline
  • Hyundai: Accent, Elantra GT, Kona, Palisade, Santa Fe, Sonata (exc. Hybrid), Tucson, Veloster
  • Jaguar: All U.S. Models
  • Jeep: All U.S. Models
  • Kia: Cadenza, Niro, Optima, Rio, Soul, Sportage, Stinger
  • Land Rover: All U.S. Models
  • Lexus: ES350 F Sport, LC500, LS500 AWD
  • Lincoln: Nautilus, Navigator, MKZ
  • Mini: All U.S. Models
  • Mitsubishi: Eclipse, Outlander
  • Nissan: Altima, Kicks, Rogue Sport, Titan
  • Ram: 1500
  • Subaru: Forrester, Legacy, Outback
  • Toyota: Camry, CH-R, Tacoma, Tundra
  • VW: All U.S. Models

We also wanted to know where shops are buying their parts from, and what is their estimated amount of “defective new” parts. The bulk of responses said they’re getting a pretty good supply of parts (with very few initial defects), of course with the majority buying in the aftermarket. Still OE parts play an important role, particularly with low volume items. And as you’d expect, the most commonly returned “defective new parts” were compressors, electrical components, condensers and hose assemblies.

Finding yf

As part of our continuing effort to document the industry’s changeover to R-1234yf, MACS once again attended the Philadelphia Auto Show to see the new models, open a few (actually all of the) hoods, and see what refrigerant is being used. This year we skipped a few brands we knew had already changed, and specifically scoped out those we had missed in previous years, as well as some we were really curious about. Here’s what we found.

  • Since dealers sold the last R-134a Jeep (Patriot MK74) in 2018, and now having converted the remaining “old” minivans (Caravans built on the RT platform were supposed to be discontinued but have held on due to high fleet demand), the only remaining FCA model that has yet to be yf converted is the Abarth 124 Spider, which we don’t expect will happen anytime soon. It’s built in Japan by Mazda and finished by Abarth in Italy, so until Mazda converts (any) vehicles (this one’s a cousin to the MX-5 Miata), we expect it to remain R-134a for the time being.
  • The only newcomer we saw from Ford was the Transit Connect van, which is made in Europe and has been the subject of controversy for some time as many are imported as passenger cars and later converted to avoid a 25% US tariff.
  • Mitsubishi may only sell three models in the US, but one of them holds the all-time record for the lowest refrigerant charge of any newly manufactured vehicle. Mirage uses only 9.5 ounces of R-134a! See Figure 6.
    Figure 6 - Mitsubishi’s Mirage has been the all-time industry leader when it comes to which car uses the LEAST amount of refrigerant, at just 9.5 ounces!
  • We didn’t check any of the BMW models as they switched their entire lineup for 2018. Same goes for all JLR (Jaguar Land Rover) and Minis. We also tied off other brands that have fully switched this year, including Alfa Romeo, Chrysler, Dodge, GMC, Jeep, Lincoln and VW.
  • We could only find two holdouts, and not surprisingly they are Mazda and Mercedes. The latter makes sense, as there was quite a controversy over the new refrigerant more than 5 years ago that included MB recalling 432 SL-Class yf vehicles through US dealers back in 2012. And now that EPA’s MY2021 cutoff has officially been revoked, there’s a real possibility that we may not see Mercedes use yf in the States for many years (if ever). As it stands now the only reason they would want (or need) to switch is if they really need the CO2 credits (which most manufacturers of large, heavy vehicles with big engines need to meet EPA targets). But Daimler is in a unique position as they build some of the most expensive, high-end luxury vehicles in country, and as such they command a premium which likely includes a few dollars to “purchase credits” from other OEMs who have extra to sell (such as those who focus on smaller, lighter, more fuel-efficient vehicles with smaller engines, hybrids and/or BEVs). Mazda on the other hand is just exactly that. 2019 Mazdas average 28.2 mpg with their lowest (CX-9) getting 23. Meanwhile MB models average only 20.9 mpg. And with both around 2% market share, you’re not dealing with huge offsets anyway.
  • Acura converted ILX, MDX and RDX production over to yf, but not all variants. MDX hybrids still use R-134a with ND-OIL11 (POE). And now that Honda uses yf in the HR-V, they have only to change the Fit to complete their lineup.
  • Hyundai switched a big portion of their systems this year. Santa Fe, Sonata, Tucson, and Veloster now use yf, which gives Hyundai a 2/3 internal majority. And in most likelihood, two of the models we saw with R-134a (Elantra and Santa Fe XL) were probably built right before the factory switch to yf, considering the Elantra GT and Santa Fe base already use it. If that’s the case, they saved hybrid models for last to switch, and as we’ve seen with others, this too makes sense given their added complexity.
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