The A/C refrigerant lines and hoses are used to 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 alu-
minum 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 system 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 con-
dition and properly routed.

The refrigerant lines and hoses are coupled to other A/C system components with block-type fittings. 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.

WARNING

WARNINGS

WARNING: The A/C system contains refrigerant under high pressure. Repairs should only be performed by
qualified service personnel. Severe personal 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 recommended. 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 suffocation and
death.

WARNING: The evaporation rate of R-134a refrigerant 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 del-
icate objects from direct contact with the refrigerant.

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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 kilopascals
(14 to 18 pounds per square inch). Do not remove or loosen the coolant pressure cap, cylinder 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 minutes before opening the cooling sys-
tem for service. Failure to observe this warning can result in serious burns from the heated engine coolant.

CAUTION

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 damage to the A/C system will result.

CAUTION: The use of A/C system sealers may result in damage to A/C refrigerant recovery/evacuation/re-
charging 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 discharged. Never open or loosen a connection before recovering the refrig-
erant.

CAUTION: If equipped, do not remove the secondary retention clip from any spring-lock coupler connection
while the refrigerant system is under pressure. Recover the refrigerant before removing the secondary
retention clip. Open the fittings with caution, even after the system has been discharged. 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 serious damage if present in more than very small quantities. Before
disconnecting a component, clean the outside of the fittings thoroughly to prevent 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 service 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 con-
tainer of refrigerant oil until you are ready to use it. Replace the cap on the oil container immediately after
using. Store refrigerant oil only in a clean, airtight, and moisture-free container.

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CAUTION: Do not overcharge the refrigerant system. 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 mixtures
are potentially dangerous and may result in fire or explosion causing property damage, personal 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 meeting 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 pres-
sure 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 fittings, 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 procedures
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 minutes. 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.

2. Position the vehicle in a wind free work area. This will aid in detecting small leaks.

3. Bring the refrigerant system up to operating temperature and pressure. This is done by allowing the engine to

run for five minutes with the A/C system set to the following:

•

Transmission in Park or Neutral with parking brake set

•

Engine idling

•

Mode control set to the outside air position

•

Blower control set to the high speed position

•

A/C set to the ON position

•

All windows open

CAUTION: A leak detector only designed for R-12 refrigerant will not detect leaks in a R-134a refrigerant
system.

4. Shut the vehicle Off and wait 2-7 minutes. Then use an electronic leak detector that is designed to detect R-134a

refrigerant and search for leaks. Fittings, lines or components that appear to be oily usually indicate a refrigerant
leak. To inspect the A/C evaporator for leaks, insert the leak detector probe into the drain tube opening or an air
outlet. A dye for R-134a is available to aid in leak detection. Use only DaimlerChrysler approved refrigerant dye.

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