MACS Monthly Newsletter - 2017 - AUG4

In all cases, if a reputable manufacturer certifies that the
machine meets the applicable SAE standard, you can be
sure it does (J2788 for R-134a equipment, J2843 for R-1234yf
machines). And you can go to the SAE website (macdb.sae.
org), type in the manufacturer's or marketer's name, and
the model number should come up. Click on that, and you
should see the performance data, which is required by another SAE standard, J2911.
So how does a manufacturer design equipment with price
points that may be significantly different, if all must meet the
same SAE standard. Because you might think, "Well the difference might be just some meaningless bells and whistles."
True, there could be a difference in the bells and whistles, but
it can go well beyond that, because there often isn't much
saving for the manufacturer with many of them.
An economy machine may well be a physically lighterduty design, less robust in many ways, from the wheels you
can see to the way the scale assembly is mounted internally,
which you can't see. The economy design just can't take a lot
of punishment, so in a shorter lifetime it will require service.
If you check the scale calibration regularly, you can pick up
a need in this area, because you sure don't want inaccurate
charging. If you have a small shop, say just you and a helper,
perhaps you can enforce a "kid gloves" approach to handling the machine. But be realistic about this. A light-duty
design may last perhaps half as long without major service
as a premium design.
One thing you should check is the specified weight difference of the economy vs. a premium machine. Don't be surprised if it's close to 50 lbs. That tells you that even if there

isn't a lot of visual external difference, the economy model
has a lot less content. Yes, the printer and identifier (for an
R-1234yf machine) will be obvious, but there will be a lot
more and you should try to find out about as many of the
differences as you can.
Maintenance/repair service itself may be harder in the
economy machine, or to put it in the more applicable reverse, the premium machine may have easier access to the
filter, oxygen sensor and other service parts. That's because
the economy design often will have fewer and larger panels
in the exterior housing, some buried fasteners, which makes
access more difficult. And larger panels can present reassembly issues as you try to keep them aligned.
There also are big differences in the content, and we don't
mean just the ones you can see, like the identifier, a printer,
the size of the display screen and the languages it covers.
You may think that if you want an R-1234yf machine without an identifier, it's going to be a light-duty design, so the
manufacturer can advertise a low price. That's not true. The
early R-1234yf machines all have been coming with identifiers (and printers) because the major market was with car
dealers, who had to present a printed record of refrigerant
recovered vs. the extra amount needed for recharge on warranty claims. The carmakers did not want to leave any room
for dealers to fudge the data.
Now, however, you should be able to order a premium
machine with the USB port so you can have the convenience
of a hand-held identifier. Note: some machines come with
USB ports, but with a built-in identifier, as these ports are for
other electronic features, not for the identifier signal. ■

There are several features that are in the bells and whistles department that you may get the chance to buy or not, depending
on equipment maker. They include:

conjunction with the vacuum pump to get deep vacuum for high
efficiency. You can be sure that whatever certified machine you
get is controlled to remove the maximum amount of refrigerant
in the shortest possible time in most vehicle systems.
* Hybrid capability: This means that it will be able to switch
from hybrid (with electric compressor) to non-hybrid. If you're
buying a new machine, we can tell you that the percentage of
hybrids being sold is increasing significantly and the capability
adds little to the price (basically a feature to flush oil from the
machine to minimize oil cross-contamination vs. belt-driven systems. You do have alternatives, such as dedicated hoses for
hybrid service and a filtering system, such as AirSept's Filter
Guard.
* Fully automatic operation of refrigerant recovery, recycle,
vacuum leak check and recharge R-134a and R-1234yf systems. This is obviously very convenient, and means you can "set
it and forget it," and go to another job. One maker (Mahle) even
offers a smartphone app so you can check to see if the operation is complete. Yes, there's a visual or audio indication in case
there's a vehicle system issue to prevent completion of the job.
* Automatic refill of the machine's internal vessel, so it's always got enough refrigerant to recharge the system.
* High and low side refrigerant charging: This can slightly
shorten the cycle time.

* Refrigerant flush: This allows you to pump liquid refrigerant through the system. It cannot remove debris, just dirty oil
(assuming there are no major restrictions). If you've used this
feature on an R-134a machine and like it, fine. If your experience
tells you that a dedicated flushing machine to remove debris is a
more useful choice, you don't need the built-in refrigerant flush.
* Larger filter: Worth having if it's in the package.
* Automatic dye and oil injection: Either is not permitted in
R-134a models for hybrids or any R-1234yf machines. But our
belief is that neither is useful, as the aftermarket injectors do the
job just fine and primarily in the case of oil, eliminate any possibility of incompatibility. The external aftermarket dye and oil
injection kits are pretty easy to use and sidestep any possibility
of cross-contamination within the machine or in case of an injection failure, result in the machine going down for service of either
injection system.
* Size of compressor: The compressor displacement is not
the definitive feature in compressor life or even machine performance. Robinair units typically have the smallest compressors because their design (patented) is to use the compressor in

August 2017

MACS Service Reports

Table of Contents for the Digital Edition of MACS Monthly Newsletter - 2017