LEXUS SC400 1991 Service Repair Manual

DRIVE BELT TENSION
INSPECTION OF DRIVE BELT TENSION
1. INSPECT DRIVE BELT'S INSTALLATION CONDITIONCheck that the drive belt fits properly in the ribbed grooves.
2. INSPECT DRIVE BELT TENSION Check that the tension is within the A range on the auto ten-
sioner scale.
If the tension is not within the A range on the scale, replace
the belt with a new one.
HINT: When replacing the drive belt with a new one, the belt's
tension should be within the B range on the belt tensioner
scale.
IDLE±UP SPEED
INSPECTION OF IDLE SPEED
1. WARM UP ENGINE
2. INSPECT IDLE SPEED
 

Trans±
mission 

Magnetic clutch
condition 

Standard idle
speed (rpm)
 

A/T
(N range) 

No engaged
 

650 rpm
 


 

Engaged 

800 rpm
 M/T No engaged 700 rpm
  Engaged 900 rpm
AC±104±
AIR CONDITIONING SYSTEM Driver Belt Tension, Idle-Up Speed
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REFRIGERANT LINES
TIGHTENING TORQUE OF
REFRIGERANT LINES
ON±VEHICLE INSPECTION
1. INSPECT HOSES AND TUBES FOR LEAKAGEUse a gas leak tester. Replace if necessary.
2. INSPECT HOSE AND TUBE CONNECTIONS FOR LOOSENESS
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AIR CONDITIONING SYSTEM Refrigerant LinesAC±105
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REPLACEMENT OF REFRIGERANT
LINES
1. RECOVER REFRIGERANT IN REFRIGERATION SYSTEMSee page AC±16
2. REPLACE FAULTY TUBE OR HOSE NOTICE: To prevent the intrusion of moisture or dirt, caps
should be placed on hose or tube ends immediately.
3. TORQUE CONNECTIONS TO SPECIFIED TORQUE
NOTICE: Connections should not be torque tighter than the
specified torque.
4. EVACUATE REFRIGERATION SYSTEM AND CHARGE WITH REFRIGERANT
See page AC±17
Specified amount: 950 + 50 g (33.44 + 1.76 oz)
5. INSPECT FOR LEAKAGE OF REFRIGERANT
Using a gas leak tester, check for leakage of refrigerant.
6. INSPECT A/C OPERATION
AC±106
±
AIR CONDITIONING SYSTEM Refrigerant Lines
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A/C UNIT
REMOVAL OF A/C UNIT
1. RECOVER REFRIGERANT IN SYSTEMSee page AC±16
2. REMOVE ENGINE See page EM±118
3. REMOVE WATER VALVE
See page AC±127
4. REMOVE BRAKE TUBES BRACKET MOUNTING BOLTS FROM DUSH PANEL
5. REMOVE EVAPORATOR See page AC±122
6. REMOVE WATER HOSE FROM HEATER RADIATOR
7. REMOVE INSULATOR RETAINER Remove the two bolts and the retainer.
8. REMOVE INSTRUMENT PANEL REINFORCEMENT See page BO±109
9. REMOVE FLOOR CARPET See page BO±118
10. REMOVE REAR AIR DUCTS Remove the nut and the air duct.
11. REMOVE HEATER TO RESISTER NO. 3 DUCT Remove the screw and the duct.
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AIR CONDITIONING SYSTEM A/C UnitAC±107
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12. REMOVE CONNECTOR BRACKET FROM UNDER SIDEOF BLOWER MOTOR
Remove the two screws and the bracket.
13. REMOVE A/C UNIT
(a) Disconnect connectors from the unit.
(b) Remove the six bolts and the A/C unit.
INSTALLATION OF A/C UNIT
1. INSTALL A/C UNIT
(a) Match the standard holes of the A/C unit with those on the vehicle.
HINT:
wV
Pull the drain hose of the A/C unit forward until the
yellow paint on the hose is visible in the engine
compartment.
w V
Insert the drain hose into the engine compartment hose
until the match marks are aligned.
(b) Tighten six bolts.
2. INSTALL CONNECTOR BRACKET
3. INSTALL HEATER TO RESISTER NO. 3 DUCT
4. INSTALL REAR AIR DUCTS
5. INSTALL FLOOR CARPET
6. INSTALL INSULATOR RETAINER
7. INSTALL WATER HOSE TO HEATER RADIATOR
8. INSTALL BRAKE TUBE BRACKET MOUNTING BOLTS
9. INSTALL WATER VALVE See page AC±127
AC±108
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AIR CONDITIONING SYSTEM Troubleshooting
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9. INSTALL EVAPORATORSee page AC±124
10. INSTALL INSTRUMENT PANEL REINFORCEMENT
11. INSTALL ENGINE See page EM±167
12. E V ACUATE AIR IN REFRIGERATION SYSTEM AND
CHARGE WITH REFRIGERANT
See page AC±17
Specified amount: 950 + 50 g (33.44 + 1.76 oz)
13. INSPECT FOR LEAKAGE OF REFRIGERANT
Using a gas leak tester, check for leakage of refrigerant.
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AIR CONDITIONING SYSTEM TroubleshootingAC±109
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COMPRESSOR
INSPECTION OF COMPRESSOR
(Magnetic Clutch)
See page AC±86
(Compressor)
1. INSTALL MANIFOLD GAUGE SET
See page AC±15
2. START ENGINE
3. INSPECT COMPRESSOR FOR METALLIC SOUND Check that there is metallic sound from the compressor when
the A/C switch is turned on.
If a metallic sound is heard, replace the compressor assem-
bly.
4. INSPECT PRESSURE OF REFRIGERATION SYSTEM See ºInspection of Refrigeration System with Manifold
Gauge Setº on page.
5. STOP ENGINE
6. INSPECT VISUALLY FOR LEAKAGE OF REFRIGERANT FROM SAFETY SEAL
If there is any leakage, replace the compressor assembly.
AC±110
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AIR CONDITIONING SYSTEM Troubleshooting
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REMOVAL OF COMPRESSOR
1. RUN ENGINE AT IDLE SPEED WITH A/C ON FORAPPROX. TEN MINUTES
2. STOP ENGINE
3. DISCONNECT NEGATIVE (±) CABLE FROM BATTERY
4. RECOVER REFRIGERANT FROM REFRIGERATION
SYSTEM
5. DISCONNECT DISCHARGE HOSE AND SUCTION HOSE
FROM COMPRESSOR
NOTICE: Cap the open fittings immediately to keep mois-
ture out of the system.
6. DISCONNECT CONNECTOR FROM MAGNETIC CLUTCH
7. REMOVE DRIVE BELT
See step 6 on page EM±118.
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AIR CONDITIONING SYSTEM CompressorAC±111
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8. REMOVE COMPRESSOR(a) Remove under cover.
(b) Remove harness from the clamp.
(c) Remove the earth wire harness set bolt.
(d) R e m o v e t h e n u t , t h r e e b o l t s , b r a c k e t a n d t h ecompressor.
DISASSEMBLY OF MAGNETIC CLUTCH
AC±112±
AIR CONDITIONING SYSTEM Compressor
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1. REMOVE PRESSURE PLATE(a) Using a SST and socket wrench, remove the shaft bolt.SST 07112±76060
(b) Install a SST on the pressure plate. SST 07112±66040
(c) Using a SST and socket wrench, remove the pressure plate.
SST 07112±76060
(d) Remove the shims from the pressure plate.
2. REMOVE ROTOR (a) Using a SST, remove the snap ring.SST 07114±84020
±
AIR CONDITIONING SYSTEM CompressorAC±113
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