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 and
quick-connect type fittings. Flat gaskets and O-rings
are 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.

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24 - 57

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: R-134a service equipment or vehicle A/C
system should not be pressure tested or leak tested
with compressed air. Mixture of air and R-134a can
be combustible at elevated pressures. These mix-
tures are potentially dangerous and may result in
fire or explosion causing property damage, per-
sonal injury or death.
Avoid breathing A/C refrigerant and lubricant vapor
or mist. Exposure may irritate eyes, nose and
throat. Use only approved service equipment meet-
ing SAE requirements to discharge R-134a system.
If accidental system discharge occurs, ventilate
work area before resuming service.

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

if the refrigerant system is fully charged with
R-134a. This is accomplished by performing a system
Charge Level-Check or Fill. If while performing this
test A/C liquid line pressure is less than 345 kPa (50
psi) proceed to System Empty procedure. If liquid
line pressure is greater than 345 kPa (50 psi) proceed
to System Low procedure. If the refrigerant system is
empty or low in refrigerant charge, a leak at any line
fitting or component seal is likely. A review of the fit-
tings, lines and components for oily residue is an
indication of the leak location. To detect a leak in the
refrigerant system, perform one of the following pro-
cedures as indicated by the symptoms.

SYSTEM EMPTY

(1) Evacuate the refrigerant system to the lowest

degree of vacuum possible (approximately 28 in Hg.).
Determine if the system holds a vacuum for 15 min-
utes. If vacuum is held, a leak is probably not
present. If system will not maintain vacuum level,
proceed to Step 2.

(2) Prepare a 0.284 Kg. (10 oz.) refrigerant charge

to be injected into the refrigerant system.

(3) Connect and dispense 0.284 Kg. (10 oz.) of

refrigerant into the evacuated refrigerant system.

(4) Proceed to Step 2 of System Low procedure.

SYSTEM LOW

(1) Determine if there is any R-134a refrigerant in

the system.

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