Refrigerant Line Couplers; Refrigerant Oil - Dodge 2000 DURANGO Service Manual

24 - 10 HEATING AND AIR CONDITIONING
DESCRIPTION AND OPERATION (Continued)
refrigerant hoses are made from lightweight alumi-
num or steel, and commonly use braze-less fittings.
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.
OPERATION
High pressures are produced in the refrigerant sys-
tem when the air conditioning compressor is operat-
ing. Extreme care must be exercised to make sure
that each of the refrigerant system connections is
pressure-tight and leak free. It is a good practice to
inspect all flexible hose refrigerant lines at least once
a year to make sure they are in good condition and
properly routed.
The refrigerant lines and hoses are coupled with
other components of the HVAC system with peanut-
block style fittings. A stat-O seal type flat steel gas-
ket with a captured compressible O-ring, and spring
lock coupler, is used to mate plumbing lines with A/C
components to ensure the integrity of the refrigerant
system.
The refrigerant lines and hoses cannot be repaired
and, if faulty or damaged, they must be replaced.

REFRIGERANT LINE COUPLERS

DESCRIPTION
Spring-lock type refrigerant line couplers are used
to connect many of the refrigerant lines and other
components to the refrigerant system. These couplers
require a special tool for disengaging the two coupler
halves.
OPERATION
The spring-lock coupler is held together by a garter
spring inside a circular cage on the male half of the
fitting (Fig. 5). When the two coupler halves are con-
nected, the flared end of the female fitting slips
behind the garter spring inside the cage on the male
fitting. The garter spring and cage prevent the flared
end of the female fitting from pulling out of the cage.
Two O-rings on the male half of the fitting are
used to seal the connection. These O-rings are com-
patible with R-134a refrigerant and must be replaced
with O-rings made of the same material.
Secondary clips are installed over the two con-
nected coupler halves at the factory for added blowoff
protection.
Fig. 5 Spring-Lock Coupler - Typical
1 – MALE HALF SPRING-LOCK COUPLER
2 – FEMALE HALF SPRING-LOCK COUPLER
3 – SECONDARY CLIP
4 – CONNECTION INDICATOR RING
5 – COUPLER CAGE
6 – GARTER SPRING
7 – COUPLER CAGE
8 – "O" RINGS

REFRIGERANT OIL

DESCRIPTION
The refrigerant oil used in R-134a refrigerant sys-
tems is a synthetic-based, PolyAlkylene Glycol (PAG),
wax-free lubricant. Mineral-based R-12 refrigerant
oils are not compatible with PAG oils, and should
never be introduced to an R-134a refrigerant system.
There are different PAG oils available, and each
contains a different additive package. The SD7H15
compressor used in this vehicle is designed to use an
SP-20 PAG refrigerant oil. Use only refrigerant oil of
this same type to service the refrigerant system.
OPERATION
After performing any refrigerant recovery or recy-
cling operation, always replenish the refrigerant sys-
tem with the same amount of the recommended
refrigerant oil as was removed. Too little refrigerant
oil can cause compressor damage, and too much can
reduce air conditioning system performance.
PAG refrigerant oil is much more hygroscopic than
mineral oil, and will absorb any moisture it comes
into contact with, even moisture in the air. The PAG
oil container should always be kept tightly capped
until it is ready to be used. After use, recap the oil
container immediately to prevent moisture contami-
nation.
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