Dodge RAM 1500 1998 Owner's Manual page 2529

24 - 42 PLUMBING
REFRIGERANT OIL
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 68
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
STANDARD PROCEDURE - REFRIGERANT
OIL LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
SERVICE PORT VALVE CORE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 70
REMOVAL - SERVICE PORT VALVE CORES
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 70
SUCTION LINE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 70
PLUMBING
DESCRIPTION - REFRIGERANT LINE
The refrigerant lines and hoses are used to carry
the refrigerant between the various air conditioning
system components. A barrier hose design with a
nylon tube, which is sandwiched between rubber lay-
ers, is used for the R-134a air conditioning system on
this vehicle. This nylon tube helps to further contain
the R-134a refrigerant, which has a smaller molecu-
lar structure than R-12 refrigerant. The ends of the
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 an exhaust manifold.
OPERATION- REFRIGERANT LINES
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 either
O-rings or dual plane seals.
The refrigerant lines and hoses cannot be repaired
and, if faulty or damaged, they must be replaced.
REMOVAL
REMOVAL - 5.9L DIESEL ENGINE
REMOVAL - 3.7L/4.7L AND 5.7L HEMI
ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
INSTALLATION
INSTALLATION - 5.9L DIESEL ENGINE
INSTALLATION - 3.7L/4.7L AND 5.7L HEMI
. . 70 ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
WARNING
ENGINE COOLING SYSTEM
WARNING: THE ENGINE COOLING SYSTEM IS
DESIGNED TO DEVELOP INTERNAL PRESSURES
OF 97 TO 123 KILOPASCALS (14 TO 18 POUNDS
PER SQUARE
LOOSEN THE COOLANT PRESSURE CAP, CYLIN-
DER BLOCK DRAIN PLUGS, RADIATOR DRAIN,
RADIATOR HOSES, HEATER HOSES, OR HOSE
CLAMPS WHILE THE ENGINE COOLING SYSTEM IS
HOT AND
OBSERVE THIS WARNING CAN RESULT IN SERI-
OUS BURNS FROM THE HEATED ENGINE COOL-
ANT. ALLOW THE VEHICLE TO COOL FOR A
MINIMUM OF 15 MINUTES BEFORE OPENING THE
COOLING SYSTEM FOR SERVICE.
INCH). DO NOT
UNDER PRESSURE.
DR
. . . . . . . . . 70
. . . . . 72
REMOVE OR
FAILURE TO