fluid level check JEEP GRAND CHEROKEE 2003 WJ / 2.G Service Manual

AUTOMATIC TRANSMISSION - 545RFE
TABLE OF CONTENTS
page page
AUTOMATIC TRANSMISSION - 545RFE
DESCRIPTION........................178
OPERATION..........................179
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AUTOMATIC
TRANSMISSION.....................179
DIAGNOSIS AND TESTING - PRELIMINARY . 180
DIAGNOSIS AND TESTING - ROAD
TESTING...........................180
DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TEST....................181
DIAGNOSIS AND TESTING - AIR CHECKING
TRANSMISSION CLUTCH OPERATION....182
DIAGNOSIS AND TESTING - CONVERTER
HOUSING FLUID LEAK................182
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR.....................183
REMOVAL............................183
DISASSEMBLY........................185
CLEANING...........................190
INSPECTION.........................190
ASSEMBLY...........................190
INSTALLATION........................197
SCHEMATICS AND DIAGRAMS
HYDRAULIC SCHEMATICS.............199
SPECIFICATIONS
TRANSMISSION.....................220
SPECIAL TOOLS
RFE TRANSMISSION.................221
4C RETAINER/BULKHEAD
DISASSEMBLY........................224
ASSEMBLY...........................224
ADAPTER HOUSING SEAL
REMOVAL............................225
INSTALLATION........................225
BRAKE TRANSMISSION SHIFT INTERLOCK
MECHANISM
DESCRIPTION........................226
OPERATION..........................226
DIAGNOSIS AND TESTING - BRAKE
TRANSMISSION SHIFT INTERLOCK......226
ADJUSTMENTS - BRAKE TRANSMISSION
SHIFT INTERLOCK...................227
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL.............228
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID.......................228DIAGNOSIS AND TESTING - FLUID
CONTAMINATION....................228
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK............................229
STANDARD PROCEDURE - FLUID AND
FILTER REPLACEMENT...............230
STANDARD PROCEDURE - TRANSMISSION
FILL...............................230
GEARSHIFT CABLE
DIAGNOSIS AND TESTING - GEARSHIFT
CABLE.............................231
REMOVAL............................231
INSTALLATION........................231
ADJUSTMENTS - GEARSHIFT CABLE......232
HOLDING CLUTCHES
DESCRIPTION........................233
OPERATION..........................234
INPUT CLUTCH ASSEMBLY
DESCRIPTION........................235
OPERATION..........................235
DISASSEMBLY........................237
ASSEMBLY...........................238
INPUT SPEED SENSOR
DESCRIPTION........................244
OPERATION..........................244
REMOVAL............................244
INSTALLATION........................244
LINE PRESSURE (LP) SENSOR
DESCRIPTION........................245
OPERATION..........................245
REMOVAL............................245
INSTALLATION........................245
LOW/REVERSE CLUTCH
DISASSEMBLY........................246
CLEANING...........................247
INSPECTION.........................247
ASSEMBLY...........................247
OIL PUMP
DESCRIPTION........................248
OPERATION..........................248
STANDARD PROCEDURE - OIL PUMP
VOLUME CHECK.....................249
DISASSEMBLY........................250
CLEANING...........................252
INSPECTION.........................252
ASSEMBLY...........................253
OIL PUMP FRONT SEAL
REMOVAL............................253
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 177

Diagnosis of these problems should always begin
by checking the easily accessible variables: fluid level
and condition, gearshift cable adjustment. Then per-
form a road test to determine if the problem has been
corrected or if more diagnosis is necessary. If the
problem persists after the preliminary tests and cor-
rections are completed, hydraulic pressure checks
should be performed.
DIAGNOSIS AND TESTING - PRELIMINARY
Two basic procedures are required. One procedure for
vehicles that are drivable and an alternate procedure for
disabled vehicles (will not back up or move forward).
VEHICLE IS DRIVABLE
(1) Check for transmission fault codes using DRBt
scan tool.
(2) Check fluid level and condition.
(3) Adjust gearshift cable if complaint was based
on delayed, erratic, or harsh shifts.
(4) Road test and note how transmission upshifts,
downshifts, and engages.
(5) Perform stall test if complaint is based on slug-
gish acceleration. Or, if abnormal throttle opening is
needed to maintain normal speeds with a properly
tuned engine.
(6) Perform hydraulic pressure test if shift prob-
lems were noted during road test.
(7)
Perform air-pressure test to check clutch operation.
VEHICLE IS DISABLED
(1) Check fluid level and condition.
(2)
Check for broken or disconnected gearshift cable.
(3) Check for cracked, leaking cooler lines, or loose
or missing pressure-port plugs.(4) Raise and support vehicle on safety stands,
start engine, shift transmission into gear, and note
following:
(a) If propeller shaft turns but wheels do not,
problem is with differential or axle shafts.
(b) If propeller shaft does not turn and transmis-
sion is noisy, stop engine. Remove oil pan, and
check for debris. If pan is clear, remove transmis-
sion and check for damaged driveplate, converter,
oil pump, or input shaft.
(c) If propeller shaft does not turn and transmis-
sion is not noisy, perform hydraulic-pressure test to
determine if problem is hydraulic or mechanical.
DIAGNOSIS AND TESTING - ROAD TESTING
Before road testing, be sure the fluid level and con-
trol cable adjustments have been checked and
adjusted if necessary. Verify that all diagnostic trou-
ble codes have been resolved.
Observe engine performance during the road test.
A poorly tuned engine will not allow accurate analy-
sis of transmission operation.
Operate the transmission in all gear ranges. Check
for shift variations and engine flare which indicates
slippage. Note if shifts are harsh, spongy, delayed,
early, or if part throttle downshifts are sensitive.
Slippage indicated by engine flare, usually means
clutch, overrunning clutch, or line presure problems.
A slipping clutch can often be determined by com-
paring which internal units are applied in the vari-
ous gear ranges. The Clutch Application chart
provides a basis for analyzing road test results.
CLUTCH APPLICATION CHART
SLP UD OD R 2C 4C L/R OVERRUNNING
P±PARKON
R±REVERSEON ON
N-NEUTRALON
D±OVERDRIVE
FIRSTON ON* ON
SECONDON ON
SECOND PRIMEON ON
THIRDON ON
FOURTHON ON
FIFTHON ON
LIMP-INON ON
2±FIRSTON ON* ON
SECONDON ON
LIMP-INON ON
1±LOWON ON ON
*L/R clutch is on only with the output shaft speed below 150 rpm.
21 - 180 AUTOMATIC TRANSMISSION - 545RFEWJ
AUTOMATIC TRANSMISSION - 545RFE (Continued)

DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TEST
An accurate tachometer and pressure test gauges
are required. Test Gauge C-3293-SP has a 300 psi
range and is used at all locations where pressures
exceed 100 psi.
Pressure Test Port Locations
Only two pressure ports are supplied on the trans-
mission case. The torque converter clutch apply and
release ports are located on the right side of the
transmission case (Fig. 2).
To determine the line pressure, there are two avail-
able methods. The DRBtscan tool can be used to
read line pressure from the line pressure sensor. The
second method is to install Line Pressure Adapter
8259 (Fig. 4) into the transmission case and then
install the pressure gauge and the original sensor
into the adapter. This will allow a comparison of the
DRBtreadings and the gauge reading to determe the
accuracy of the line pressure sensor. The DRBtline
pressure reading should match the gauge reading
within  10 psi.
In order to access any other pressure tap locations,
the transmission oil pan must be removed, the pres-
sure port plugs removed and Valve Body Pressure
Tap Adapter 8258-A (Fig. 5) installed. The extensions
supplied with Adapter 8258-A will allow the installa-
tion of pressure gauges to the valve body. Refer to
(Fig. 3) for correct pressure tap location identifica-
tion.
TEST PROCEDURE
All pressure readings should be taken with the
transmission fluid level full, transmission oil at the
normal operating temperature, and the engine at
1500 rpm. Check the transmission for proper opera-
tion in each gear position that is in question or if a
specific element is in question, check the pressure
readings in at least two gear positions that employ
that element. Refer to the Hydraulic Schematics at
the rear of this section to determine the correct pres-
sures for each element in a given gear position.
Fig. 2 Torque Converter Pressure Locations
1 - TCC RELEASE
2 - TO COOLER
3 - TCC APPLY
4 - FROM COOLER
5 - LINE PRESSURE SENSOR
Fig. 3 Pressure Tap Locations
Fig. 4 Line Pressure Adapter 8259
1 - LINE PRESSURE SENSOR PORT
2 - LINE PRESSURE SENSOR
3 - TOOL 8259
4 - PRESSURE TAP
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 181
AUTOMATIC TRANSMISSION - 545RFE (Continued)

(8) Engine starts must be possible with shifter
lever in PARK or NEUTRAL gate positions only.
Engine starts must not be possible in any other gate
positions other than PARK or NEUTRAL.
(9) With shifter lever handle push-button not
depressed and lever detent in:
²PARK position- apply forward force on center of
handle and remove pressure. Engine start must be
possible.
²PARK position- apply rearward force on center
of handle and remove pressure. Engine start must be
possible.
²NEUTRAL position- engine start must be possi-
ble.
²NEUTRAL position, engine running and brakes
applied- Apply forward force on center of shift han-
dle. Transmission should not be able to shift into
REVERSE detent.
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn the
fluid into foam. This aerates the fluid and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has three primary causes.
(1) Internal clutch slippage, usually caused by low
line pressure, inadequate clutch apply pressure, or
clutch seal failure.
(2) A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged main cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.(3) Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²overheat that generates sludge (fluid break-
down)
²failure to reverse flush cooler and lines after
repair
²failure to replace contaminated converter after
repair
The use of non-recommended fluids can result in
transmission failure. The usual results are erratic
shifts, slippage, abnormal wear and eventual failure
due to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw-
ing the dipstick.
Engine coolant in the transmission fluid is gener-
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission, an overhaul is necessary.
The transmission cooler and lines should be
reverse flushed whenever a malfunction generates
sludge and/or debris. The torque converter should
also be replaced at the same time.
Failure to flush the cooler and lines will result in
recontamination. Flushing applies to auxiliary cool-
ers as well. The torque converter should also be
replaced whenever a failure generates sludge and
debris. This is necessary because normal converter
flushing procedures will not remove all contami-
nants.
21 - 228 AUTOMATIC TRANSMISSION - 545RFEWJ
BRAKE TRANSMISSION SHIFT INTERLOCK MECHANISM (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transmssion has too much fluid, the
geartrain churns up foam and cause the same condi-
tions which occur with a low fluid level.
In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can inter-
fere with normal valve, clutch, and accumulator opera-
tion. Foaming can also result in fluid escaping from the
transmission vent where it may be mistaken for a leak.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
The transmission has a dipstick to check oil level.
It is located on the right side of the engine. Be sure
to wipe all dirt from dipstick handle before removing.
The torque converter fills in both the P (PARK)
and N (NEUTRAL) positions. Place the selector lever
in P (PARK) to be sure that the fluid level check is
accurate.The engine should be running at idle
speed for at least one minute, with the vehicle
on level ground.At normal operating temperature(approximately 82 C. or 180 F.), the fluid level is cor-
rect if it is in the HOT region (cross-hatched area) on
the oil level indicator. The fluid level will be approx-
imately at the upper COLD hole of the dipstick at
70É F fluid temperature.
NOTE: Engine and Transmission should be at nor-
mal operating temperature before performing this
procedure.
(1) Start engine and apply parking brake.
(2) Shift the transmission into DRIVE for approxi-
mately 2 seconds.
(3) Shift the transmission into REVERSE for
approximately 2 seconds.
(4) Shift the transmission into PARK.
(5)
Hook up DRBtscan tool and select transmission.
(6) Select sensors.
(7) Read the transmission temperature value.
(8) Compare the fluid temperature value with the
chart. (Fig. 59)
(9) Adjust transmission fluid level shown on the
dipstick according to the chart.
NOTE: After adding any fluid to the transmission,
wait a minimum of 2 minutes for the oil to fully
drain from the fill tube into the transmission before
rechecking the fluid level.
(10) Check transmission for leaks.
Fig. 59 Transmission Fluid Temperature Chart
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 229
FLUID AND FILTER (Continued)

STANDARD PROCEDURE - FLUID AND FILTER
REPLACEMENT
For proper service intervals (Refer to LUBRICA-
TION & MAINTENANCE/MAINTENANCE SCHED-
ULES - DESCRIPTION).
REMOVAL
(1) Hoist and support vehicle on safety stands.
(2) Place a large diameter shallow drain pan
beneath the transmission pan.
(3) Remove bolts holding front and sides of pan to
transmission.
(4)
Loosen bolts holding rear of pan to transmission.
(5) Slowly separate front of pan away from trans-
mission allowing the fluid to drain into drain pan.
(6) Hold up pan and remove remaining bolts hold-
ing pan to transmission.
(7) While holding pan level, lower pan away from
transmission.
(8) Pour remaining fluid in pan into drain pan.
(9)
Remove screw holding filter to valve body (Fig. 60).
(10) Separate filter from valve body and oil pump
and pour fluid in filter into drain pan.
(11) Remove and discard the oil filter seal from the
bottom of the oil pump.
(12) If replacing the cooler return filter, use Oil
Filter Wrench 8321 to remove the filter from the
transmission.
(13) Dispose of used trans fluid and filter(s) prop-
erly.
INSPECTION
Inspect bottom of pan and magnet for excessive
amounts of metal. A light coating of clutch material
on the bottom of the pan does not indicate a problemunless accompanied by a slipping condition or shift
lag. If fluid and pan are contaminated with excessive
amounts of debris, refer to the diagnosis section of
this group.
CLEANING
(1) Using a suitable solvent, clean pan and mag-
net.
(2) Using a suitable gasket scraper, clean original
sealing material from surface of transmission case
and the transmission pan.
INSTALLATION
(1) Install a new primary oil filter seal in the oil
pump inlet bore. Seat the seal in the bore with the
butt end of a hammer, or other suitable tool.
CAUTION: The primary oil filter seal MUST be fully
installed flush against the oil pump body. DO NOT
install the seal onto the filter neck and attempt to
install the filter and seal as an assembly. Damage to
the transmission will result.
(2) Place replacement filter in position on valve
body and into the oil pump.
(3) Install screw to hold filter to valve body (Fig.
60). Tighten screw to 4.5 N´m (40 in. lbs.) torque.
(4) Install new cooler return filter onto the trans-
mission, if necessary. Torque the filter to 14.12 N´m
(125 in.lbs.).
(5) Place bead of MopartRTV sealant onto the
transmission case sealing surface.
(6) Place pan in position on transmission.
(7) Install bolts to hold pan to transmission.
Tighten bolts to 11.8 N´m (105 in. lbs.) torque.
(8) Lower vehicle and fill transmission with
MopartATF +4, type 9602 fluid.
STANDARD PROCEDURE - TRANSMISSION
FILL
To avoid overfilling transmission after a fluid
change or overhaul, perform the following procedure:
(1) Remove dipstick and insert clean funnel in
transmission fill tube.
(2) Add following initial quantity of MopartAT F
+4 to transmission:
(a) If only fluid and filter were changed, add10
pints (5 quarts)of ATF +4 to transmission.
(b) If transmission was completely overhauled,
torque converter was replaced or drained, and
cooler was flushed, add24 pints (12 quarts)of
ATF +4 to transmission.
(3) Check the transmission fluid (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
45RFE/FLUID - STANDARD PROCEDURE) and
adjust as required.
Fig. 60 Transmission Filters - 4X4 Shown
1 - PRIMARY OIL FILTER
2 - COOLER RETURN FILTER
3 - COOLER RETURN FILTER BYPASS VALVE
4 - VALVE BODY
21 - 230 AUTOMATIC TRANSMISSION - 545RFEWJ
FLUID AND FILTER (Continued)

STANDARD PROCEDURE - OIL PUMP VOLUME
CHECK
Measuring the oil pump output volume will deter-
mine if sufficient oil flow to the transmission oil
cooler exists, and whether or not an internal trans-
mission failure is present.
Verify that the transmission fluid is at the proper
level. Refer to the Fluid Level Check procedure in
this section. If necessary, fill the transmission to the
proper level with MopartATF +4, type 9602, Auto-
matic Transmission Fluid.
(1) Disconnect theTo coolerline at the cooler
inlet and place a collecting container under the dis-
connected line.CAUTION: With the fluid set at the proper level,
fluid collection should not exceed (1) quart or inter-
nal damage to the transmission may occur.
(2) Run the engineat 1800 rpm, with the shift
selector in neutral. Verify that the transmission fluid
temperature is below 104.5É C (220É F) for this test.
(3) If one quart of transmission fluid is collected in
the container in 30 seconds or less, oil pump flow vol-
ume is within acceptable limits. If fluid flow is inter-
mittent, or it takes more than 30 seconds to collect
one quart of fluid, refer to the Hydraulic Pressure
tests in this section for further diagnosis.
(4) Re-connect theTo coolerline to the transmis-
sion cooler inlet.
Fig. 90 Oil Pump Reaction Shaft
1 - PUMP HOUSING 4 - SEAL RING (5)
2 - SEAL 5 - REACTION SHAFT SUPPORT
3 - OIL FILTER SEAL 6 - PUMP VALVE BODY
WJAUTOMATIC TRANSMISSION - 545RFE 21 - 249
OIL PUMP (Continued)

NV242HD REAR RETAINER
(1) Apply bead of MopartSealer, or LoctiteŸ
Ultra Gray, to mating surface of rear retainer. Sealer
bead should be a maximum of 3/16 in.
(2) Install rear retainer on rear case. Tighten
retainer bolts to 20-27 N´m (15-20 ft. lbs.) torque.
(3) Install new output shaft bearing snap-ring
(Fig. 91). Lift mainshaft slightly to seat snap-ring in
shaft groove, if necessary.
(4) Apply 3 mm (1/8 in.) wide bead of Mopartgas-
ket maker or silicone adhesive sealer to mounting
surface of extension housing. Allow sealer to set-up
slightly before proceeding.(5) Install extension housing on rear retainer.
(6) Install extension housing bolts and tighten to
35-46 N´m (26-34 ft. lbs.).
COMPANION FLANGE
(1) Lubricate companion flange hub with transmis-
sion fluid and install flange on front shaft.
(2) Install new seal washer on front shaft.
(3) Install flange on front shaft and tighten nut to
122-176 N´m (90-130 ft. lbs.).
INSTALLATION
(1) Mount transfer case on a transmission jack.
(2) Secure transfer case to jack with chains.
(3) Position transfer case under vehicle.
(4) Align transfer case and transmission shafts
and install transfer case on transmission.
(5) Install and tighten transfer case attaching nuts
to 35 N´m (26 ft. lbs.) torque (Fig. 4).
(6) Align and connect propeller shafts. (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - INSTALLATION)
(7) Fill transfer case with correct fluid. Check
transmission fluid level. Correct as necessary.
(8) Install rear crossmember and skid plate, if
equipped. Tighten crossmember bolts to 41 N´m (30
ft. lbs.) torque.
(9) Remove transmission jack and support stand.
(10) Connect shift rod to transfer case range lever.
(11) Connect transfer case vent hose and transfer
case position sensor.
(12) Adjust transfer case shift cable.
(13) Lower vehicle and verify transfer case shift
operation.
Fig. 91 Install Output Bearing Snap-ring
1 - REAR RETAINER
2 - SNAP-RING
3 - REAR BEARING
WJTRANSFER CASE - NV242 21 - 307
TRANSFER CASE - NV242 (Continued)

(6) Connect front propeller shaft and install rear
propeller shaft. (Refer to 3 - DIFFERENTIAL &
DRIVELINE/PROPELLER SHAFT/PROPELLER
SHAFT - INSTALLATION)
(7) Fill transfer case with correct fluid. Check
transmission fluid level. Correct as necessary.
(8) Install rear crossmember (Fig. 71) and skid
plate, if equipped. Tighten crossmember bolts to 41
N´m (30 ft. lbs.) torque.
(9) Remove transmission jack and support stand.
(10) Verify transfer case is in NEUTRAL. Connect
shift cable to transfer case range lever.
(11) Lower vehicle and verify transfer case shift
operation.
(12) Adjust the transfer case shift cable, if neces-
sary.
SPECIFICATIONS
TRANSFER CASE - NV247
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Bolt, crossmember 41-47 30.2-34.7 -
Plug, Detent 16-24 11.8-17.7 -
Plugs, drain/fill 20-34 15-25 -
Bolts, front brg. retainer 16-24 11.8-17.7 -
Bolts, case half 27-34 19.9-25 -
Nut, companion flange 122-176 90-130 -
Bolts, rear extension 27-34 19.9-25 -
Lock-nut, shift 27-34 19.9-25 -
Nuts, T-case mount stud 33-41 24.3-30.2 -
Fig. 71 Crossmember Installation
1 - CROSSMEMBER
2 - REAR TRANSMISSION MOUNT
21 - 336 TRANSFER CASE - NV247WJ
TRANSFER CASE - NV247 (Continued)

REFRIGERANT
DESCRIPTION
The refrigerant used in this air conditioning sys-
tem is a HydroFluoroCarbon (HFC), type R-134a.
Unlike R-12, which is a ChloroFluoroCarbon (CFC),
R-134a refrigerant does not contain ozone-depleting
chlorine. R-134a refrigerant is a non-toxic, non-flam-
mable, clear, and colorless liquefied gas.
Even though R-134a does not contain chlorine, it
must be reclaimed and recycled just like CFC-type
refrigerants. This is because R-134a is a greenhouse
gas and can contribute to global warming.
OPERATION
R-134a refrigerant is not compatible with R-12
refrigerant in an air conditioning system. Even a
small amount of R-12 added to an R-134a refrigerant
system will cause compressor failure, refrigerant oil
sludge or poor air conditioning system performance.
In addition, the PolyAlkylene Glycol (PAG) synthetic
refrigerant oils used in an R-134a refrigerant system
are not compatible with the mineral-based refriger-
ant oils used in an R-12 refrigerant system.
R-134a refrigerant system service ports, service
tool couplers and refrigerant dispensing bottles have
all been designed with unique fittings to ensure that
an R-134a system is not accidentally contaminated
with the wrong refrigerant (R-12). There are also
labels posted in the engine compartment of the vehi-
cle and on the compressor identifying to service tech-
nicians that the air conditioning system is equipped
with R-134a.
REFRIGERANT OIL
DESCRIPTION
The refrigerant oil used in R-134a refrigerant sys-
tems is a synthetic-based, PolyAlkylene Glycol (PAG),
wax-free lubricant. Mineral-based R-12 refrigerant
oils are not compatible with PAG oils, and should
never be introduced to an R-134a refrigerant system.
There are different PAG oils available, and each
contains a different additive package. The 10PA17
compressor used in this vehicle is designed to use an
ND8 PAG refrigerant oil. Use only refrigerant oil of
this same type to service the refrigerant system.
OPERATION
After performing any refrigerant recovery or recy-
cling operation, always replenish the refrigerant sys-
tem with the same amount of the recommended
refrigerant oil as was removed. Too little refrigerant
oil can cause compressor damage, and too much can
reduce air conditioning system performance.PAG refrigerant oil is much more hygroscopic than
mineral oil, and will absorb any moisture it comes
into contact with, even moisture in the air. The PAG
oil container should always be kept tightly capped
until it is ready to be used. After use, recap the oil
container immediately to prevent moisture contami-
nation.
STANDARD PROCEDURE - REFRIGERANT OIL
LEVEL
When an air conditioning system is assembled at
the factory, all components except the compressor are
refrigerant oil free. After the refrigerant system has
been charged and operated, the refrigerant oil in the
compressor is dispersed throughout the refrigerant
system. The accumulator, evaporator, condenser, and
compressor will each retain a significant amount of
the needed refrigerant oil.
It is important to have the correct amount of oil in
the refrigerant system. This ensures proper lubrica-
tion of the compressor. Too little oil will result in
damage to the compressor. Too much oil will reduce
the cooling capacity of the air conditioning system.
It will not be necessary to check the oil level in the
compressor or to add oil, unless there has been an oil
loss. An oil loss may occur due to a rupture or leak
from a refrigerant line, a connector fitting, a compo-
nent, or a component seal. If a leak occurs, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system after the repair has been made.
Refrigerant oil loss will be evident at the leak point
by the presence of a wet, shiny surface around the
leak.
Refrigerant oil must be added when a accumulator,
evaporator coil, or condenser are replaced. See the
Refrigerant Oil Capacities chart. When a compressor
is replaced, the refrigerant oil must be drained from
the old compressor and measured. Drain all of the
refrigerant oil from the new compressor, then fill the
new compressor with the same amount of refrigerant
oil that was drained out of the old compressor.
Refrigerant Oil Capacities
Component ml fl oz
A/C System 130 4.40
Receiver Drier 70 2.37
Condenser 10 0.34
Evaporator 50 1.69
Compressordrain and measure
the oil from the old
compressor - see
text.
WJPLUMBING 24 - 75