ect LEXUS SC300 1991 Service Repair Manual

DATE:NOVEMBER 29, 1996
TitleALTERNATE REFRIGERANTS AND A/C RETROFITPage 1 of 2
Effective January 1, 1996, the E.P.A. has officially banned the manufacture of Refrigerant 12 (Freon).
As a result, surplus supplies of R±12 will begin to dwindle over the ne\
xt several years until, eventually,
R±12 will no longer be available.
This uncertainty about the availability of R±12 has caused significant concerns for Lexus dealers when
servicing HVAC systems not using R±134a refrigerant. Similarly, the reduced availability of R±12 has
prompted demands for R±134a retrofit kits and/or alternate refrigerants. Thi\
s TSB will clarify Lexus's
current recommendations for servicing and retrofitting HVAC systems on Lexus vehicles using R±12
refrigerant.
ALTERNATE REFRIGERANTS:
Previously, the E.P.A. has endorsed other alternative refrigerants. These endorsements, combin\
ed with
the uncertain future availability of R±12, have lead to a limited accept\
ance of using alternative refrigerants
when servicing or retrofitting R±12 HVAC systems. Use of these refrigerants can lead to several service
related problems, including:
Poor system performance and leak detection capabilities.
Contamination of R±12 and R±134a during refrigerant recovery and r\
ecycling.
Recently the E.P.A. released a statement clarifying that approval of alternative refrige\
rants relates only
to the toxicology, flammability, ozone depletion and global warming characteristics. The approval does
not imply acceptability of alternative refrigerants use with respect to serviceability or performance.
TOYOTA MOTOR SALES, U.S.A. ENDORSES THE USE OF R±134a AS THE ONLY ACCEPTABLE ALTERNATIVE REFRIGERANT FOR VEHICLES USING R±12.
R±12 AVAILABILITY:
It is estimated that existing R±12 supplies will meet market demand i\
n 1996. Beyond that, Lexus will
supply R±12 to it's dealers from a strategic reserve. These strategic reserves are alloca\
ted specifically
for distribution to Lexus dealers for repair of their customers' R±12 H\
VAC systems. TMS projects these
reserves may meet dealer demand through early 1998. After that, we believe R±12 will no longer be re\
adi-
ly available and dealers will begin to retrofit customer vehicles with R\
±134a.
REF: HEATING & AIR CONDITIONING
NO:AC007±96
MODEL:ALL MODELS
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COIL SPRING COMPRESSOR SST # 09727-30020-02Page 1 of 1
Please observe the following procedures each time this tool is used:
SPECIAL SERVICE TOOLS
SS93±001
MARCH 12, 1993
ALL MODELS
Carefully inspect your spring compressor for cracks or other deformation prior to
each use.

Use only on Lexus vehicles. Use on other applications may exceed the tool design
limits.
 Be sure spring is free from its seat (unstuck) prior to compressing.
 Do not compress the coil spring further than needed to facilitate the repair.
When using suspension coil spring compressor be sure to follow the instructi\
ons outlined in
the repair manual as well as the caution label placed on the tool (see illustration below).
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CHANGE IN SUPPLY PARTS FOR INNER REAR VIEW MIRROR (CONT'D)Page 2 of 3
1) Remove Center Visor
a) Remove the visor arm set clip (Figure 1).
b) Remove the two attachment screws.
Figure 1
Figure 2
Figure 3
Figure 4 2) Remove Inner Rear View Mirror
a) Remove mirror set screw (Figure 2).
b) Disconnect the mirror wire harness.
INNER REAR VIEW MIRROR REMOVAL:
Note: To prevent damage to plastic parts,
tape the screwdriver tip before use.
COMPONENT DISASSEMBLY:
a) Using snap ring pliers, remove the spring.
b) Remove the two holders and the spacer (Figure 3).
NOTE: Do not remove the mirror base from the windshield.
COMPONENT ASSEMBLY:
a) Reinstall components by installing the spacer, two holders and spring.
b) Install the spring using snap ring pliers (Figure 4).
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CHANGE IN SUPPLY PARTS FOR INNER REAR VIEW MIRROR (CONT'D)Page 3 of 3
a) Install inner rear view mirror by re±installing
attachment set screw (Figure 5).
INNER REAR VIEW MIRROR & CENTER
VISOR INSTALLATION:
PARTS LOCATION:
Note: Use thread locking compound on
set screw to ensure screw reten-
tion.
b) Re±connect wire harness.
Note: Check review mirror dimming operation before re±installation of
center visor.
c) Install center visor by re±installing two attachment screws.
d) Re±install visor arm set clip.
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REAR SUSPENSION NOISEPage 1 of 2
PREVIOUS PART
NUMBER
48341-24040
48341-24070
Center Support Nut
Projection
New
Rear Spring Bumper
Previous
Rear Spring Bumper
SUSPENSION
SU95±005
OCTOBER 20, 1995
SC 300/400
The rear spring bumper has been changed in production on 1995 SC 300/400 in\
an effort to reduce
clunking/rattling noises.
SERVICE HINT: A similar clunking/rattling type noise can be generated by an
improperly torqued center support nut (27 N m, 280 kgf.cm,
20 ft.lbs).
PRODUCTION EFFECTIVE
:
Starting VINs: JT8UZ30C*S0047966 JT8JZ31C*S0030524
PART NUMBER INFORMATION
: NEW PART NUMBER PART NAME QTY
48341-24071 Bumper, Rear Spring 2
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REAR SUSPENSION NOISEPage 2 of 2
WARRANTY INFORMATION:
OPCODE DESCRIPTION TIME OPN T1 T2
R&R Rear Shock AbsorberAssembly
(both sides including 48341-24040 or
replacement of spring 48341-24070
bumpers and all necessary
adjustments)
Replacement of the rear spring bumper under warranty is limited to correction of a prob\
lem based upon a
customer 's complaint.
482201A 1.8 91 41
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SERVICE HINTS FOR REFRIGERANT LEAK DETECTIONPage 1 of 3
Use of electronic leak detectors for checking A/C systems refrigerant leaka\
ge is the only
method approved by TMS. This type of leak detector is sensitive not onl\
y to refrigerant, but
also sensitive to numerous petrochemical substances (motor oil, gasolin\
e, solvents, etc.)
commonly found in a repair shop environment. Because this sensitivity c\
ould diminish the leak
detector 's capacity for accurate leak detection, some service hints have been pro\
vided to help
increase the accuracy of your diagnosis.
SERVICE HINTS:
1. Visual Inspection: Do a quick visual inspection under the hood for signs of refrigerant
leakage. Check for areas of heavy oil leakage at block and piping joint\
s. Many times
these areas have accumulated road dust and dirt.
2. Inspection with leak detector: NOTE: Make sure the system is fully charged. Operate
the system to increase refrigerant pressure. Shut the system off before inspecting with
leak detector.
A. Checking for leakage at a joint:
Wipe the oil/dirt accumulation off the joint with a
clean rag. Do not use solvents to clean the joint. Refrigerant is heavi\
er than air so
start checking for leaks with the detector wand about 1/4 in. below the \
joint. Move the
wand slowly across and around each joint (see illustration below).
Piping Joint Move detector wand slowly across
and around each joint.
Block Joint
HEATING &
AIR CONDITIONING
AC95±001
MARCH 03, 1995
ALL MODELS
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SERVICE HINTS FOR REFRIGERANT LEAK DETECTIONPage 2 of 3
B.Checking for leakage at the evaporator: The evaporator drain hose provides an
excellent access point to check for refrigerant leakage from the evapora\
tor. Be sure
to raise the vehicle on a lift so that the evaporator is as far as possi\
ble from any
petrochemical source that may be on the shop floor. When leak checking in this area,
turn the system off, pinch off the evaporator drain hose, and wait 10 to 15 minutes to
allow the refrigerant to accumulate in the evaporator case. When the s\
ystem is ready
to check, release the drain hose and hold the leak detector wand about 1\
/4 inch below
the drain opening (see diagram).
NOTE: Do not allow the leak detector tip to come in contact with water from th\
e evaporator.
C. Checking for leakage at front compressor seal:
Front compressor seal leaks are
probably the most difficult leaks to detect accurately. Special diagnostic procedures must be followed
for the best success. Make sure the system is fully charged. Operate the \
system with a pressure gauge
installed and assure that the system has correct system pressures. Shut off the engine. Begin the
leak check by placing the detector probe along the bottom half of the compr\
essor clutch. Move the wand
slowly across the bottom of the compressor clutch. Be careful not to expose t\
he detector wand tip to
any oil residue as this may cause a false leakage reading.
Evaporator
Drain Hose
Verify correct system pressure. Move dectector wand slowly across the
bottom half of the compressor clutch.
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SERVICE HINTS FOR REFRIGERANT LEAK DETECTIONPage 3 of 3
D. Checking for leakage at service valves or pressure switches:
Small accumulations of refrigerant gas under the service valve caps or p\
ressure switch connectors is
normal. When checking for leaks at these points, use the following proc\
edures to assure the highest
accuracy:
1. Remove the service valve cap or pressure switch connector.
2. Allow the service valve or pressure switch to remain uncapped for approx\
imately
20 minutes. This will allow the air to circulate and carry away the acc\
umulated
refrigerant. (This is a good time to leak check other areas of the syst\
em).
3. Do not use compressed air to flush out the service valve or pressure swi\
tch
cavity. Petroleum residue from inline oilers or compressor lubrication may ca\
use
false readings.
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Some SC 300/SC 400 vehicles may have a sunvisor which falls away slightly from the roof
when placed in the full upright position. To improve visor retention, the position of an internal
clip has been modified in production.
BODY
BO92±004
APRIL 24, 1992
SC 300/SC 400
PART NUMBER INFORMATION:
New Part NumberPrev. Part NumberDescriptionSide
NOTE:Before replacing the Sunvisor assembly, ensure that shaft is fully seated into the
sunvisor by pushing the sunvisor further onto the shaft. This may
seat the internal clip into
the groove on the shaft.
PRODUCTION EFFECTIVE:
FROM: November, 1991
VIN: SC 400: JT8UZ30C9N0011202
SC 300: JT8JZ30C9N0002890
Same
º
º
Same
º
º
Same
º
º
Same
º
º Medium Gray
SpruceIvory
SC 300/SC 400 IMPROVED SUNVISOR HINGE RETENTION (REVISED) Page 1 of 1
Medium Gray
SpruceIvory
Medium Gray SpruceIvory
Medium Gray SpruceIvory RH
RH
RH
RH w/Sunroof
RH w/Sunroof
RH w/Sunroof LH
LH
LH
LH w/Sunroof
LH w/Sunroof
LH w/Sunroof
74310±24120±03
74310±24120±07
74310±24120±08
74310±24130±03
74310±24130±07
74310±24130±08
74320±24130±03
74320±24130±07
74320±24130±08
74320±24080±03
74320±24080±07
74320±24080±08
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