PTEN_0321 - 28

TOOL BRIEFING

p This screenshot from Mitchell 1 shows the
procedure to condition a GM vehicle for an
A/C Performance Test. Even though vehicles
are similar, you should use vehicle specific
information.

TAP INTO VIRTUAL
A/C SERVICE TRAINING
After a shop's legal
requirements for A/C service
have been met, it's a good idea
to plan for ongoing training
opportunities so technicians
are knowledgeable about the
technical aspects regarding the
advanced systems present on
today's vehicles.
The Motor Age webinar " A/C
Services Challenges Today and
Tomorrow " presented by Motor
Age Technical Editor Pete Meier
and Shop Owner G. Truglia
explores R-1234yf systems, heat
pump designs for hybrid and EV
platforms, and the systems that
will require R-152a in the
near future.
Motor Age Training offers technicians access to Pay Per View
webinars, free YouTube channel
videos, and ASE study guides.
www.motoragetraining.com

28

PTEN

MARCH 2021

across a vehicle manufacturer's complete
line, or that what is correct for one tear
is the same for another. For example, a
2000 Ford Explorer has a capacity of 30
oz. of R-134. A 2010 Ford Explorer uses
44 oz. of R-134, and a 2020 Explorer uses
34 oz. of R-1234yf. Most technicians
would incorrectly assume that a newer
vehicle will use a lesser amount of R-134,
but as you see, the newer 2010 uses more
refrigerant. Most technicians will also
assume that a vehicle uses significantly
less R-1234yf, but when you compare the
2000 Explorer to the 2020, you can see
the R-1234yf capacity is higher.
In the past, over or under-charging an
A/C system by 10-15 percent would not
be a big issue, and in most driving conditions the system would function just
fine. With many vehicles now using relatively small amounts of refrigerant, some
using less than one pound, the refrigerant
charge is critical to system performance.
There are some systems that will be
adversely affected if the system is over- or
under-charged by as little as two ounces.
The next most critical tool to use while
checking an A/C system is a refrigerant sealant detector. I recently taught
a HVAC course at an auto parts store.
While I was preparing for the class, I
toured the store shelves to determine
what type of products they had available

www.VehicleServicePros.com

for technicians and the DIYer to charge
or repair A/C. The thing that surprised
me most was that every product they sold
had a sealant in the refrigerant charge
can. Why this is important is that if you
were to recover refrigerant that a DIYer
had charged with this product, you would
be allowing the sealant to enter your RRR
machine where it could cause damage to
some of the machine's components.
In order to prevent this, use a sealant
detector. If sealant is detected, either
refuse to work on the system, use a filter to remove the sealant, or use an older
machine that does not have some of the
electronic solenoids that could be damaged during the recovery process.
Along the same lines, a refrigerant
identifier should be used to identify the
type of refrigerants or whether there are
any contaminants in the system. Just a
note, if you had your EPA 609 certification, you would be familiar with the need
for identifying the refrigerant prior to
connecting your machine.
The next " must " tool is your scan tool.
It is critical to check for fault codes in
the HVAC system. With most vehicles
using multiple modules to communicate
almost every task, you should also perform a " Health Check " , which checks
every module in the vehicle to determine
if there are any communication faults.
http://www.motoragetraining.com http://www.VehicleServicePros.com
PTEN_0321

Table of Contents for the Digital Edition of PTEN_0321
