Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
Refrigerant: Technical Service Bulletins
Contaminated R12 Refrigerant - Testing & Handling
FILE IN SECTION: 1 - HVAC
BULLETIN NO.: 53-12-05
DATE: May, 1995
SUBJECT:
Contaminated R12 Refrigerant Testing and Handling
MODELS:
1994 and Prior Passenger Cars and Trucks with R12 A/C Systems
The J 39851 "PureGuard" R12 refrigerant monitor was recently shipped to all GM dealers as an essential tool to test R12 refrigerant. Dealers are
strongly urged to install this protective device on their ACR3 or other R12 recovery equipment immediately. The PureGuard is easily installed on any
recovery cart (20 minutes), requires no recovery cart modifications, is fully automatic (no training required) and does not increase the time required to
perform normal A/C service procedures. Proper use of this tool can:
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Prevent damage to your R12 recovery/recycling equipment.
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Prevent contamination of previously recovered R12 in the recovery tank.
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Prevent loss of your recovered R12 as contaminated refrigerant will activate automatic air purge system.
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Prevent the spread of contaminated R12 to other vehicles you service.
If your dealership has multiple R12 recovery stations which are not protected, use the PureGuard to check the refrigerant in these recovery tanks for
contamination at least once each week. Simply connect the PureGuard blue service hose (that would normally be connected to the vehicle low side
service port) to the red or vapor side of any recovery cart tank and run the test. It is also important to check a tank containing recovered/recycled material
for purity before installation on your charging equipment. Even new R12 refrigerant purchased from sources other than GM should be tested for
contamination prior to use.
Sources of Contaminated R12 Refrigerant
Since refrigerant testing has not been a standard practice in the mobile A/C repair industry, the amount of R12 refrigerant contamination is unknown. As
R12 prices rise and supplies are depleted, it is anticipated that contaminated R12 refrigerant may become more prevalent from the following as well as
other sources:
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The use of R12 refrigerant substitutes without installation of unique service fittings and proper identification labeling.
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Improper use of R12 substitutes, such as topping off R12 systems with R134a or other refrigerants available to "do-it-yourselfers".
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Poor quality or contaminated new or reprocessed R12 refrigerant.
R12 can and should continue to be used to service vehicles built with R12 as long as it is available. Combining any refrigerant with R12 results in a
refrigerant mixture which cannot be used in an A/C system.
R134a is the only substitute refrigerant approved by GM and should only be used when the appropriate retrofit service bulletin procedures are explicitly
followed. Use of any other substitute refrigerant requires the purchase of additional dedicated recovery, recycling (if applicable) and charging equipment
to service each substitute refrigerant used.
However, you should know that the Environmental Protection Agency (EPA) has listed several products as acceptable replacements for R12 mobile A/C
systems under the Significant New Alternatives Policy (SNAP). Some of these products are: R134a, R401c (a DuPont refrigerant blend) and FRIGC
(another refrigerant blend). It is important to understand that the SNAP program only considers the health, safety and environmental characteristics of a
chemical. It does not test for A/C system cooling performance or durability. That judgment is deferred to the vehicle manufacturer. Use of any R12
refrigerant substitute without dedicated service equipment, unique fittings, labels and refrigerant testing prior to recovery, could result in contamination
of the R12 supply and the loss of the R12 recycling program.
What To Do When Contamination is Detected
Repeat the test to verify contaminated refrigerant is present. Clear the PureGuard following the instructions listed on the face panel, then perform a
second test to verify that the vehicle A/C system contains contaminated or mixed refrigerant.
Contact the vehicle owner to advise that previous A/C system repairs were apparently performed with an R12 refrigerant substitute. Suggest the owner
