carry the refrigerant between the various A/C system
components. The refrigerant lines and hoses for the
R-134a system on this vehicle consist of a barrier-
hose design with a nylon tube sandwiched between
rubber layers. The nylon tube helps to contain the
R-134a refrigerant, which has a smaller molecular
structure than R-12 refrigerant. The ends of the
refrigerant lines are made from lightweight alumi-
num or steel, and commonly use braze-less fittings.

Any kinks or sharp bends in the refrigerant lines

and hoses will reduce the capacity of the entire A/C
system and can reduce the flow of refrigerant in the
system. The radius of all bends in the flexible hose
refrigerant lines should be at least ten times the
diameter of the hose and the refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) away from the exhaust manifold(s) and
exhaust pipe(s).

OPERATION

High pressures are produced in the refrigerant sys-

tem when the A/C compressor is operating. 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 to

other A/C system components with block-type fit-
tings. An O-ring seal, or a flat steel gasket with an
integral O-ring (dual plane seal), is used to mate the
refrigerant line fittings with A/C system 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.

WARNINGS

WARNING: The A/C system contains refrigerant
under high pressure. Repairs should only be per-
formed by qualified service personnel. Severe per-
sonal injury or death may result from improper
service procedures.

WARNING: Avoid breathing the refrigerant and
refrigerant oil vapor or mist. Exposure may irritate
the eyes, nose, and/or throat. Wear eye protection
when servicing the A/C refrigerant system. Serious
eye injury can result from direct contact with the
refrigerant. If eye contact occurs, seek medical
attention immediately.

WARNING: Do not expose the refrigerant to open
flame. Poisonous gas is created when refrigerant is
burned. An electronic leak detector is recom-
mended. Severe personal injury or death may result
from improper service procedures.

WARNING: If accidental system discharge occurs,
ventilate the work area before resuming service.
Large amounts of refrigerant released in a closed
work area will displace the oxygen and cause suf-
focation and death.

WARNING: The evaporation rate of R-134a refriger-
ant at average temperature and altitude is extremely
high. As a result, anything that comes in contact
with the refrigerant will freeze. Always protect the
skin or delicate objects from direct contact with the
refrigerant.

WARNING: The R-134a service equipment or the
vehicle refrigerant system should not be pressure
tested or leak tested with compressed air. Some
mixtures of air and R-134a have been shown to be
combustible at elevated pressures. These mixtures
are potentially dangerous, and may result in fire or
explosion causing property damage, personal injury
or death.

WARNING: The engine cooling system is designed
to develop internal pressures of 97 to 123 kilopas-
cals (14 to 18 pounds per square inch). Do not
remove or 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 under pressure.
Allow the vehicle to cool for a minimum of 15 min-
utes before opening the cooling system for service.
Failure to observe this warning can result in seri-
ous burns from the heated engine coolant.

CAUTIONS

CAUTION: Never add R-12 to a refrigerant system
designed to use R-134a. Do not use R-12 equipment
or parts on a R-134a A/C system. These refrigerants
are not compatible and damage to the A/C system
will result.

CAUTION: Never use R-12 refrigerant oil in a A/C
system designed to use R-134a refrigerant oil.
These refrigerant oils are not compatible and dam-
age to the A/C system will result.

24 - 58

PLUMBING

CAUTION: The use of A/C system sealers may
result in damage to A/C refrigerant recovery/evacu-
ation/recharging

equipment

and/or A/C

system.

Many federal, state/provincial and local regulations
prohibit the recharge of A/C systems with known
leaks. DaimlerChrysler recommends the detection
of A/C system leaks through the use of approved
leak detectors and fluorescent leak detection dyes.
Vehicles found with A/C system sealers should be
treated as contaminated and replacement of the
entire A/C refrigerant system is recommended. A/C
systems found to be contaminated with A/C system
sealers, A/C stop-leak products or seal conditioners
voids the warranty for the A/C system.

CAUTION: Recover the refrigerant before opening
any fitting or connection. Open the fittings with
caution, even after the system has been dis-
charged. Never open or loosen a connection before
recovering the refrigerant.

CAUTION: If equipped, do not remove the second-
ary retention clip from any spring-lock coupler con-
nection

while

the

refrigerant

system

under

pressure. Recover the refrigerant before removing
the secondary retention clip. Open the fittings with
caution, even after the system has been dis-
charged. Never open or loosen a connection before
recovering the refrigerant.

CAUTION: The internal parts of the A/C system will
remain stable as long as moisture-free refrigerant
and refrigerant oil is used. Abnormal amounts of
dirt, moisture or air can upset the chemical stability.
This may cause operational troubles or even seri-
ous damage if present in more than very small
quantities.

Before

disconnecting

component,

clean the outside of the fittings thoroughly to pre-
vent contamination from entering the refrigerant
system. Keep service tools and the work area clean.
Do not open the refrigerant system or uncap a
replacement component until you are ready to ser-
vice the system. Immediately after disconnecting a
component from the refrigerant system, seal the
open fittings with a cap or plug. This will prevent
contamination from entering the A/C system.

CAUTION: Refrigerant oil will absorb moisture from
the atmosphere if left uncapped. Do not open a
container of refrigerant oil until you are ready to
use it. Replace the cap on the oil container immedi-
ately after using. Store refrigerant oil only in a
clean, airtight, and moisture-free container.

CAUTION: Do not overcharge the refrigerant sys-
tem. Overcharging will cause excessive compressor
head pressure and can cause compressor noise
and A/C system failure.

DIAGNOSIS AND TESTING

REFRIGERANT SYSTEM LEAKS

WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.

If the A/C system is not cooling properly, determine

if the refrigerant system is fully-charged (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
DIAGNOSIS AND TESTING - REFRIGERANT SYS-
TEM CHARGE LEVEL).

If the refrigerant system is low or empty; a leak at

a refrigerant line, connector fitting, component, or
component seal is likely. While an oily residue on or
near refrigerant system lines, connector fittings, com-
ponents, or component seals can indicate the general
location of a possible refrigerant leak, the exact leak
location should be confirmed with an electronic leak
detector prior to component repair or replacement.
An electronic leak detector designed for R-134a
refrigerant is recommended for locating and confirm-
ing refrigerant system leaks. See the operating
instructions supplied by the equipment manufacturer
for proper care and use of this equipment.

To detect a leak in the refrigerant system, perform

one of the following procedures as indicated by the
results of the refrigerant system charge level test.

SYSTEM EMPTY

(1) Evacuate the refrigerant system (Refer to 24 -

HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).

(2) Connect and dispense 0.283 kilograms (0.625

pounds or 10 ounces) of R-134a refrigerant into the
evacuated refrigerant system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - REFRIGERANT SYSTEM
CHARGE).

(3) Proceed to the SYSTEM LOW procedures.

PLUMBING

24 - 59

PLUMBING (Continued)

SYSTEM LOW

(1) Position the vehicle in a wind-free work area.

This will aid in detecting small leaks.

(2) Bring the refrigerant system up to operating

temperature and pressure. This is done by allowing
the engine to run at idle under the following condi-
tions for five minutes, then turning the engine off.

(a) Front windows are open.
(b) Transaxle in Park.
(c) Front heater-A/C controls set to outside air,

panel mode, blower high, and compressor engaged.
(3) Wait five to seven minutes and, with the

engine not running, use a electronic R-134a leak
detector and search for leaks. Because R-134a refrig-
erant is heavier than air, the leak detector probe
should be moved slowly along the bottom side of all
refrigerant lines, connector fittings and components.

(4) To inspect an evaporator for leaks, insert the

electronic leak detector probe into a floor outlet or
the recirculation air intake.

REFRIGERANT SYSTEM CHARGE LEVEL

WARNING: Refer to the applicable warnings and cau-
tions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS).
Failure to follow the warnings and cautions could
result in possible personal injury or death.

NOTE: Always refer to the underhood HVAC Speci-
fication Label for the refrigerant fill capacity of the
vehicle being serviced.

The procedure that follows should be used to deter-

mine whether the refrigerant system contains the
proper refrigerant charge. Symptoms of an improper
refrigerant charge (low) include: poor A/C perfor-
mance, fog emitted from the air outlets, a hissing
sound from the A/C expansion valve/evaporator area.
There are two different methods with which the
refrigerant charge level may be tested:

1. Using a DRBIII

t scan tool, a thermocouple and

the Charge Determination Chart (Fig. 1). Refer to
the appropriate diagnostic information.

2. Using a manifold gauge set, a thermocouple and

the Charge Determination Chart (Fig. 1).

A temperature probe is required to measure liquid

line temperature. The clamp-on, Type K thermocou-
ple temperature probe used in this procedure is
available through the DaimlerChrysler Professional
Service Equipment (PSE) program. This probe (PSE
#66-324-0014 or #80PK-1A) is compatible with tem-
perature-measuring instruments that accept Type K
thermocouples, and have a miniature connector

input.

Other

temperature

probes

are

available

through aftermarket sources; however, all references
in this procedure will reflect the use of the probe
made available through the PSE program.

In order to use the temperature probe, a digital ther-

mometer will also be required. If a digital thermometer
is not available, an adapter is available through the
PSE program that will convert any standard digital
multimeter into a digital thermometer. This adapter is
designed to accept any standard Type K thermocouple.
If a digital multimeter is not available, this tool is also
available through the PSE program.

NOTE: When connecting the service equipment
couplings to the refrigerant system service ports,
be certain that the valve of each coupling is fully
closed. This will reduce the amount of effort
required to make the connection.

(1) Remove the caps from the refrigerant system

service ports and attach a manifold gauge set or a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 to the refriger-
ant system.

(2) Attach a clamp-on thermocouple to the A/C liq-

uid line. The thermocouple must be placed as close to
the A/C pressure transducer as possible to accurately
observe liquid line temperature.

(3) Bring the refrigerant system up to operating

temperature and pressure. This is done by allowing
the engine to run at idle under the following condi-
tions for five minutes.

(a) Front windows are open.
(b) Transaxle in Park.
(c) Front A/C-heater controls set to fresh air, full

cool, panel mode, high blower speed and the A/C
compressor engaged.
(4) Raise the liquid line (discharge) pressure to

about 1793 kPa (260 psi) by placing a piece of card-
board over part of the front of the A/C condenser. To
place the cardboard properly, remove the upper radi-
ator sight shield from the front fascia. Cover only
enough of the A/C condenser to raise and maintain
the liquid line pressure at the specified level.

(5) Observe the liquid line (discharge) pressure

and liquid line temperature. Using the Charge Deter-
mination Chart (Fig. 1), determine whether the
refrigerant system is operating within the proper
charge range.

(a) If the refrigerant system is operating in the

undercharged area of the chart, add 0.057 kilogram
(0.125 pound or 2 ounces) of R-134a refrigerant to
the system.

(b) If the refrigerant system is operating in the

overcharged area of the chart, reclaim 0.057 kilo-
gram (0.125 pound or 2 ounces) of refrigerant from
the system.

24 - 60

PLUMBING

PLUMBING (Continued)

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