GMC 1998 Savana Van Owner's Manual page 310

Air Conditioning Refrigerants
Not all air conditioning refrigerants
are
the same.
If
the air conditioning system in your vehicle needs
refrigerant, be swe the proper refrigerant is used. If
you're not sure, ask your dealer.
TYPE QTY Front Only QTY Front
and Rear
Refrigerant 3.00 lbs. (1.36 kg)
4.5
lbs. (2.04 kg)
R-
134a
Air Conditioning Refrigerant Capacity
NOTICE:
R-134a refrigerant is not compatible with R-12
refrigerant in an air conditioning system. R-12 in
an R-134a system will cause compressor failure,
refrigerant oil sludge, or poor air conditioning
system performance.
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