MACS Monthly Newsletter - 2017 - OCT7

SIMPLY MORE CONFUSION

When you do the math, that comes to a 28% reduction in refrigerant used, but also an astounding 70%
reduction in oil charge. When you think about it, it's
amazing that they can still remove the same amount
of heat, and build an air conditioning system that
gives the same performance, while using so much
less refrigerant and oil. See Figure 8.

But there's another thing that adds to the confusion, and that's the oil type specification. When
searching in Alldata under Service & Repair it says,
"A/C Refrigerant Oil Replacement; Recommended PAG oil: SP-10; P/N 38897-P13-A01AH: 120ml
(4 oz.)." At first glance, a technician might be inclined to believe that 4 ounces is the total system
oil charge specification. But further research shows
that 4 ounces is in fact the amount of oil that is supplied in a new bottle of oil listed under that Honda
factory part number! So, in effect what Alldata is
telling you is that if you were to buy that product,
you would get a bottle that's filled with 4 ounces of
PAG oil, and not that 4 ounces is the correct total oil
charge amount for the system.
And we've heard this from several technicians
and even some industry veterans who've asked us
to verify the information for them. That's just a part
number and quantity on a bottle of oil, not a charge
amount. A simple search for the part number online
will provide many results to back up this theory.
However, keep in mind that when you don't have
a definitive answer as to what the exact system oil
charge is supposed to be, 4 ounces does seem to be
a reasonable number when looking at it from a ratioto-refrigerant perspective. In fact, some technicians
would rather play it safe and even put in 4 or 5
ounces, just to have a little room for error.
But the problem remains, that we know we're
dealing with an oil separator, and we're not using
as much oil because we're not circulating as much
through the system. In other words, oil capacities
are down significantly, and the Ford F-150 is a good
example.

SO... WHAT THEN DO WE TELL THE CUSTOMER?
Getting back to the CR-V, that guy is still waiting
for an answer about how much oil is supposed to be
in that system, and so far, we don't have any definitive answer we can give!
This is where years of experience, dozens of
MACS classes, countless conversations with other
experts and a whole lot of speculation come into
play, and we just have to give our best guestimate
and explain to the technician how we've come up
with the answer (and hope he sees our point of
view, understands what we're saying, and agrees).
It's quite frustrating too, because we know that
someone knows how much oil goes in there. Someone in engineering, or on the factory assembly line,
or at the A/C system supplier 's shop has to put
the correct amount of oil into the system, and that
amount needs to be precise. Unfortunately, the information doesn't always make its way to the technician in the service bay, either at the dealer or in
the aftermarket.
We can speculate all day about why an OEM
would not tell us this crucial data point. Perhaps
they figure the A/C system will never be completely replaced, or will not be totally flushed out. Maybe they think only a damaged component is likely
to be replaced, and so that's why they only give you
component replacement information rather than an
exact charge amount for the whole system. Or maybe it's simply too complicated to pass the information along for the multitude of models and configurations they build for markets around the world.
That sounds plausible, but they seem to do a pretty
good job of telling you how much gas the tank can
hold, and how many quarts of oil go into the engine. Even how many quarts for the transmission
and gallons of coolant make their way into owner 's
manuals and service websites. But
too often there's a
missing link when
it comes to A/C oil
information.
We do our due
diligence and check
all the information
sources we have

FORD'S F-150

Steve Schaeber

Let's compare a brand new, 2017 Ford F-150 pickup truck to its older brother that was built in the
year 2000. Back then, the single cab (with only a
front evaporator under the dash and no rear air)
used 40 ounces of refrigerant, and 9 ounces of oil
(a 22.5% ratio). But 17 years later that same truck
filled with R-1234yf uses only 29 ounces of refrigerant and 2.7 ounces of oil (a miniscule 9.3% ratio).

Figure 8: These labels compare the amount of refrigerant and oil used between 2000 and 2017 Ford F-series trucks.

October 2017

MACS Service Reports

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