Jeep Wrangler TJ. Manual - part 598

PLUMBING

DESCRIPTION

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 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.

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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

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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 open.
(b) Transmision in Park or Neutral with the

park brake set.

mode, high blower speed and A/C 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 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.

RECOVERY/RECYCLING STATION

When servicing the A/C system, a R-134a refriger-

ant recovery/recycling/charging station that meets
SAE Standard J2210 must be used (Fig. 1). Contact
an automotive service equipment supplier for refrig-
erant recovery/recycling/charging equipment. See the
operating instructions supplied by the equipment
manufacturer for proper care and use of this equip-
ment.

MANIFOLD GAUGE SET

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 suction (low-side) service port. This port is
located on the A/C liquid line.

• HIGH PRESSURE GAUGE HOSE - The high

pressure hose (Red with Black stripe) attaches to the
discharge (high-side) service port. This port is located
on the A/C discharge line.

• 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-
fold gauge set are opened, the refrigerant in the sys-
tem will escape through this hose.

Fig. 1 Refrigerant Recovery/Recycling Station -

Typical

1 - R-134a REFRIGERANT STATION

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PLUMBING

PLUMBING (Continued)

REFRIGERANT SYSTEM CHARGE LEVEL

NOTE: Always refer to the A/C Underhood Specifi-
cation Label for the refrigerant fill capacity of the
vehicle being serviced.

The following procedure should be used to deter-

mine whether the A/C refrigerant system contains
the proper refrigerant charge. Symptoms of an
improper refrigerant charge (low) include: poor A/C
performance, fog emitted from the air outlets, a hiss-
ing sound from the A/C orifice tube/liquid line 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. 3). Refer to
the appropriate diagnostic information.

2. Using a manifold gauge set, a thermocouple and

the Charge Determination Chart (Fig. 3).

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

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

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 as
possible to the inlet end of the A/C orifice tube 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) Transmission in Park or Neutral with the

parking brake set.

panel outlet 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 the front of the A/C condenser. To place
the cardboard properly, remove the upper radiator
sight shield (if equipped) and cover only enough of
the A/C condenser to raise and maintain the liquid
line pressure at the previously specified level.

Fig. 2 Manifold Gauge Set - Typical

1 - HIGH PRESSURE GAUGE
2 - VALVE
3 - VACUUM/REFRIGERANT HOSE (YELLOW W/BLACK STRIPE)
4 - HIGH PRESSURE HOSE (RED W/BLACK STRIPE)
5 - LOW PRESSURE HOSE (BLUE W/BLACK STRIPE)
6 - VALVE
7 - LOW PRESSURE GAUGE

PLUMBING

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PLUMBING (Continued)

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