MACS Monthly Newsletter - 2020 - FEB2

motorcraftservice.com

neutronicsinc.com

Figure 1: Most conventional A/C systems use an evaporator
temperature sensor to control the clutch, and Ford products
are no exception. But although the sensor on many vehicles
can be removed while working under the dashboard, Ford
vehicles (phase-in since 2014) have the sensor integrated
into the evaporator, so it cannot be serviced separately. Further, the evaporator on most models is built into the Climate
Control Housing, so for service the entire assembly must be
removed, and a complete housing may be the only replacement component available.

Figure 2: This kit is designed to detect stop-leak type sealer in an
A/C system. It uses a coupling that attaches to the service valve,
a refrigerant flowmeter, one from a pack of cartridges, each with a
fixed orifice. The two couplings in the kit are for R-12 and R-134a
systems.

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The ugly truth, we fear (a few years down the road of
course), is when the vehicle is an older, high-mileage one,
and the problem is evaporator leakage. Then the motorist
may want to gamble on a dose of sealer with a refrigerant charge. You may be prudent enough to decline this
approach, but a vehicle that was given (and failed) the
"treatment" may end up in your shop. Safeguard your
recovery/recycle/recharge machine by always getting a
vehicle service history on the A/C, and if you're suspicious of the answers, there is the Neutronics ACSD (sealant detection kit) Part No. 7-08-1000-51-0. This kit (Figure
2) was introduced years ago for R-12 and R-134a systems
and more recently was redesigned to also include an R1234yf coupler (Figure 3). It takes just three minutes to
perform the test, which checks refrigerant flow from the
service valve into a calibrated orifice in a disposable test
cartridge and through a flowmeter. The orifice has to be
wetted (with water), which will cause stop leak sealer to
solidify. If flow through the cartridge slows markedly,
say 30% as indicated by the flowmeter, that is evidence
that stop-leak type sealant is present. The test kit is not
used for "seal sweller" type additives that reduce leakage
from connector seals that have shrunk. n

Figure 3: This is a new coupling for the sealer detection kit.
It connects to an R-1234yf service valve.

REAR HVAC: WHAT TO DO?
Rear HVAC systems in full-size SUVs and minivans are
a long-standing performance problem. On older vehicles,
many shops just advise the customer to forgo detailed diagnosis and repair unless the customer has a usage situation, such as a large family, that would make satisfactory
rear A/C operation really important. Otherwise, the shop
can tell the customer that the rear systems, starting with

February 2020

the tubing from the front, are prone to leaks, among other
ailments that affect performance, and the lowest-cost "repair" is to install block-off fittings on the refrigerant lines.
That, the motorist will be told, not only will "eliminate"
the problem (as well as the rear cooling) but leave heating
for cold weather.
If the motorist doesn't really need that rear system cool-

MACS Service Reports

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MACS Monthly Newsletter - 2020

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