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3. Turn on the vehicle and the AC system.
4. Open the red high side ball valve on the sight glass.
5. SLOWLY OPEN THE BLUE LOW SIDE BALL VALVE ON THE SIGHT GLASS.
6. Wait for 1 minute after the liquid refrigerant is removed from the sight glass. This allows any refrigerant in the blue
hose to enter the AC system.
7. Close the low side coupler by turning the knob counterclockwise (manual couplers only.) Remove the blue coupler
from the low side.
8. Turn off the AC system and the vehicle.
POSSIBLE CONTAMINANTS THAT CAN BE SEEN IN THE INSPECTION GLASS INCLUDE:
CARBONIZED OIL PARTICLES When oil is exposed to high temperatures
RUBBER PARTICLES Aggressive acids penetrating rubber parts
MOISTURE Leaks, incorrect or insufficient vacuum or wrong/inferior quality additives
METAL SILVER/CHIPS Compressor seizure or metal parts abrasion
AGGRESSIVE ACIDS Chemical reaction between moisture and refrigerant/oil or incorrect oil mixtures
VARIOUS PARTICLES Soiled compounds created from using poor quality or incorrect additives such as leak
stop agents, UV dye or oil mixture composites
UNACCEPTABLE CONDITIONS
These conditions when viewed in the inspection glass are an indication of serious system/component issues
DARK GREEN
Excessive UV dye in the system
RUBBER/PLASTIC COMPOUNDS
Aged seals, strong additives reacting
with seals and hoses, receiver dryer
failure or too much dryer wear
RED/ORANGE
Excessive red leak tracing dye in the
system
BUBBLE/PEARLS
Moisture in the system, contamination
caused by insufficient quality additives,
incorrect vacuum pulled during
previous services
LIGHT BROWN
System or compressor subjected to
overheating
GEL-LIKE, CRYSTALLIZED TEXTURE
Insufficient quality leak stop agents
reacting with refrigerant/oil or UV dye,
no/incorrect vacuum pulled before leak
stop applications
DARK BROWN OR BLACK
System or compressor subjected to
excessive overheating
CREAM/UNCLEAR TEXTURE
Aggressive flushing agent residues
reacting with aluminum and teflon
coating on the compressor’s parts,
incorrect flushing and vacuum pulled
after flushing
METAL CHIPS/PARTICLES
Compressor seizure caused by oil
starvation or incorrect lubrication
IMBALANCED LIQUIDS MIXTURE
Application of universal/incorrect oils,
unbalanced, non-homogeneous mixture
of various oils
ACCEPTABLE CONDITIONS
These conditions when viewed in the inspection glass are an indication that no issues are present
ACCEPTABLE CONDITION
Pure mix of refrigerant and lubricant
ACCEPTABLE CONDITION
Appropriate mix of refrigerant, lubricant
and UV dye