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

24 - 34

PLUMBING

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.

PLUMBING

24 - 35

PLUMBING (Continued)

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.

24 - 36

PLUMBING

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) Windows open.
(b) Transmision in Neutral with the park brake

set.

mode, high blower fan speed and the A/C compres-
sor 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 A/C evaporator for leaks, insert

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

STANDARD PROCEDURE

REFRIGERANT SYSTEM SERVICE EQUIPMENT

WARNING: Eye protection must be worn when ser-
vicing an air conditioning refrigerant system. Turn
off (rotate clockwise) all valves on the equipment
being used before connecting to, or disconnecting
from the refrigerant system. Failure to observe
these warnings may result in personal injury or
death.

WARNING: Review the warnings and cautions in the
front of this section before performing the following
operation (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - WARNINGS) and (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING - CAU-
TIONS).

RECOVERY/RECYCLING STATION

When servicing the air conditioning system, a

R-134a refrigerant recovery/recycling/charging sta-
tion that meets SEA Standard J2210 must be used
(Fig. 1). Contact an automotive service equipment
supplier for refrigerant recovery/recycling/charging
equipment. See the operating instructions supplied
by the equipment manufacturer for proper care and
use of this equipment.

MANIFOLD GAUGE SET

CAUTION: Do not use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.

A manifold gauge set may be needed with some

recovery/recycling/charging equipment (Fig. 2). The
service hoses on the gauge set being used should
have manual (turn wheel), or automatic back-flow
valves at the service port connector ends. This will
prevent refrigerant from being released into the
atmosphere.

MANIFOLD GAUGE SET CONNECTIONS

CAUTION: Do not use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.

• LOW PRESSURE GAUGE HOSE - The low

pressure hose (Blue with Black stripe) attaches to
the low side service port. This service port is located
on the suction line, near the air intake plenum at the
right rear of the engine compartment.

• HIGH PRESSURE GAUGE HOSE - The high

pressure hose (Red with Black stripe) attaches to the
high side service port. This service port is located on
the liquid line between the A/C condenser and the
A/C evaporator, near the front of the engine compart-
ment.

• RECOVERY, RECYCLING, EVACUATION

AND CHARGING HOSE - The center manifold
hose (Yellow, or White, with Black stripe) is used to
recover, evacuate, and charge the refrigerant system.
When the low or high pressure valves on the mani-

Fig. 1 Refrigerant Recovery/Recycling Station -

Typical

1 - R-134a REFRIGERANT STATION

PLUMBING

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PLUMBING (Continued)

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