vacuum LEXUS SC400 1991 Service Repair Manual

ABBREVIATIONS USED IN THIS
MANUAL
ABS Anti±Lock Brake System J/B Junction Block
A/C Air Conditioner LED Light Emitting Diode
ALR Automatic Locking Retractor LH Left±Hand
APPROX. Approximation LHD Left±Hand Drive
A/T, ATM Automatic Transmission LLC Long Life Coolant (Year Around Coolant)
ATF Automatic Transmission Fluid Max. Maximum
BTDC Before Top Dead Center Min. Minimum
BVSV Bimetal Vacuum Switching Valve MP Multipurpose
CALIF. Vehicles Sold in California N Neutral
CB Circuit Breaker OD, O/D Overdrive
DOHC Double Over Head Cam O/S Oversize
DP Dash Pot P & BV Proportioning and Bypass Valve
ECT Electronic Controlled Transmission PCV Positive Crankcase Ventilation
ECU Electronic Controlled Unit PS Power Steering
EFI Electronic Fuel Injection RH Right±Hand
EGR Exhaust Gas Recirculation RL Rear Left
ELR Emergency Locking Retractor RR Rear Right
EPR Evaporator Pressure Regulator RR, Rr Rear
ESA Electronic Spark Advance SRS Supplemental Restraint System
EVAP Evaporative (Emission Control) SSM Special Service Materials
EX Exhaust (manifold, valve) SST Special Service Tools
Ex. Except STD Standard
FIPG Formed in Place Gasket SW Switch
FL Front Left TDC Top Dead Center
FL Fusible Link TDCL Total Diagnostic Communication Link
FPU Fuel Pressure Up Temp. Temperature
FR Front Right TRAC Traction Control System
FR, Fr Front TWC Three±Way Catalyst
HAC High Altitude Compensation VSV Vacuum Switching Valve
IG Ignition VTV Vacuum Transmitting Valve
IN Intake (manifold, valve) w/ With
INT Intermittent w/o Without
ISC Idle Speed Control
IN±34±
INTRODUCTION Abbreviations Used in This Manual
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12. Observe the following precautions to avoid damage to theparts:
(a) Do not open the cover or case of the ECU unless
absolutely necessary (If the IC terminals are touched, the
IC may be destroyed by static electricity.).
(b) To pull apart electrical connectors, pull on the connectoritself, not the wires (See page BE±2).
(c) Be careful not to drop electrical components, such as sensors or relays. It they are dropped on a hard floor,
they should be replaced and not reused.
(d) When checking continuity at the wire connector, insert the tester probe carefully to prevent terminals from
bending.
(e) To disconnect vacuum hoses, pull on the end, not the middle of the hose.
(f) When steam cleaning an engine, protect the distributor,
coil and air filter from water.
(g) Ne ve r use an imp a ct wre n ch to re mo ve or in sta ll temperature switches or temperature sensors.
(h) When using a vacuum gauge, never force the hose onto
a connector that is too large. Use a step±down adapter
instead. Once the hose has been stretched, it may leak.
13. Tag hoses before disconnecting them: (a) When disconnecting vacuum hoses, use tags to identify
how they should be reconnected.
(b) After completing a job, double check that the vacuum hoses are properly connected. A label under the hood
shows the proper layout.
14. Installation of wheels The wheel assemblies are of the uni±directional type and
must be rotated only between the front and rear as illustrated.
Wheels are marked with turning direction indicators.
When installing the wheels, check the marks carefully and
install the wheel correctly.
15. Bleeding of traction control system When repairing the brake master cylinder or TRAC system,
bleed the air out of the TRAC system (See page BR±7).
CAUTION: Since the fluid is under high pressure, it could
spray out with great force, so be careful.
IN±6
±
INTRODUCTION General Repair Instructions
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R±12 AIR CONDITIONER SYSTEM RETROFIT ± AC001±98 April 3, 1998
Page 4 of 4
E. Replace Receiver
1. Remove original R±12 Receiverand discard.
2. Measure oil and pour 1/2 of specified amount of oil into the
ªOUTº side of new Receiver (see
table on page 1 for amount).
3. Black out the sight glass on block ± joint ± type Receiver with black
paint.
4. Lubricate and install the O±rings on the Receiver connections.
5. Install Receiver.
F. Using R134a Recovery equipment,
evacuate, charge, and leak test the
system (Use equipment
manufacturer 's recommended
procedure).
1. Evacuate for 45 minutes.
2. Vacuum check.
3. If vacuum check is OK, add remaining 1/2 compressor oil using
the recovery equipment.
Using recovery / recycling /
recharging equipment charge
the system with the remaining
½ of the specified amount of oil
from step E2.
4. Charge system with specified amount of R134a. (reference table
on page 1).
5. Perform a gas leak check.
G. Confirm cooling performance of Air Conditioning system.
H. Install retrofit labels:
1. Choose R134a ªUSE ONLYº label
for proper oil type ( ND±OIL 8).
2. Using a ball point pen, enter the proper retrofit refrigerant and oil
charges on the caution label.
3. Cross out unused type of compressor oil on caution label.
4. Affix labels in a prominent location such as radiator support, underside
of hood, or suspension tower area.
5. Remove any R±12 labels.Repair
Procedure
(continued)FF Type
Black out
Replace O±Rings
Retrofit Receiver
BAG type
Replace O±Ring
Retrofit Receiver
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Part No.Part NameNote
07110-58011
(07117-58010)
(07117-78011)
(07117-88013)
(07117-88022)
(07117-88040)
07110-58040
07112-66040
07112-76060
07114-82020
07117-48050
Air Conditioner
Service Tool Set
(Refrigerant Drum
Service Valve)
(Refrigerant
Charging Gauge)
(Refrigerant
Charging Hose)
(Refrigerant
Charging Hose)
(Refrigerant
Charging Hose)
(Stop Valve)
Charging Hose Kit.
w/Stop Valve
Magnetic Clutch
Stopper
Magnetic Clutch
Remover
Snap Ring Pliers
Vacuum Pump Assy
Orange Color
If you require a stop valve, please order this kit.
Rated voltage AC220V
Illustration
IllustrationPart No.Part NameNote
09082-00015TOYOTA
Electrical TesterMeasure voltage currant and resistance
Blue Color
Green Color
PREPARATION
SST (SPECIAL SERVICE TOOLS)
±
AIR CONDITIONING SYSTEM PreparationAC±13
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EVACUATING AIR IN
REFRIGERATION SYSTEM AND
CHARGING WITH REFRIGERANT
HINT: Before charging the system with refrigerant, be sure
carry out a complete evacuation of the system.
1. INSTALL MANIFOLD GAUGE SET TO SERVICE VALVES See page AC±15
2. EVACUATE AIR IN REFRIGERATION SYSTEM (a) Connect the center hose of the manifold gauge set to the vacuum pump.
(b) Open both the high and low hand valves and run the vacuum pump.
HINT: If opening the low pressure hand valve pulls the high
pressure gauge into the vacuum range, there is no blokage
in the system.
(c) After ten minutes or more, check that the low pressure gauge indicates 99.99 kPa (750 mmHg, 29.53 in.Hg) or
more of vacuum.
HINT: If the reading is not 99.99 kPa (750 mmHg, 29.53
in.Hg) or more of vacuum, close both the high and low hand
valves of the manifold gauge set and stop vaccum pump.
Then, check the system for leaks and repair as necessary.
(d) Close both the high and low hand valves and stop the
vacuum pump.
(e) Leave the system in this condition for five minutes or longer and check that there is no change in the gauge
indicator.
3. INSTALL CHARGING CYLINDER NOTICE: When handling the charging cylinder, always
follow the directions given in the instruction manual.
(a) Charge the proper amount of refrigerant in charging cylinder.
(b) Connect the center hose to charging cylinder. NOTICE: Do not open both high and low hand valves of
manifold guage set.
(c) Press on the schrader valve on the side of manifold gauge and expel the air inside of the center hose.
±
AIR CONDITIONING SYSTEM Evacuation Air in Refrigeration
System and Charging with RefrigerantAC±17
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No.Gauge reading kPa (kgf/cm2, psi)ConditionProbable cause Remedy
LO: 1.5 ± 2.0(21 ±28, 147 ±196)
HI: 14.5 ± 15.0(206 ±213, 1422 ±1471)
Normal coolingNormally functioning
system
During operation, pressure at low
pressure side sometimes becomes a
vacuum and sometimes normal.Periodically cools
and then fails to
cool.Moisture present in
refrigeration system.(1). Replace receiver
(2). Remove moisturein system through
repeatedly
evacuating air
Inspection of Refrigeration System with Manifold Gauge Set
This is a method in which the trouble is located by using a manifold gauge s\
et. (See ºInstallation of Manifold
Gauge Setº on page AC±15) Read the manifold gauge pressure when the following conditions are es\
tablished:
(a) Temperature at the air inlet with the switch set at RECIRC is 30±35 °C (86±95 °F).
(b) Engine running at 2,000 rpm.
(c) Blower fan speed control switch set at high speed.
(d) Temperature control switch set at max. cool side.
HINT: It should be noted that the gauge indications may vary slightly due to\
ambient temperature conditions.
NOTICE:
w Always recover refrigerant before removing the parts in the refrigerant \
line and evacuating air.
w Evacuate air and charge proper amount of purified refrigerant after installing th\
e parts in the
refrigerant line.
AC±100
±
AIR CONDITIONING SYSTEM Troubleshooting
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No.Gauge reading kPa (kgf/cm2, psi)ConditionProbable causeRemedy
Vacuum indicated at low pressure
side, very low pressure indicated at
high pressure.
Pressure too high at low pressure
sides, pressure too low at high
pressure side.
Refrigerant does not
circulate
Does not cool(Cools from time
to time in some
cases)

Frost or dew seen
on piping before
and after receiver
or expansion
valve
(1) Check heat sensing
tube for gas
leakage and
replace expansion
If (1) is normal
(2) Clean out dirt in expansion valve by
blowing with air if
not able to remove
dirt replace
expansion valve
(3) Replace receiver
Does not coolInsufficient
compressionRepair or replace
compressor
NOTICE:
w Always recover refrigerant before removing the parts in the refrigerant line a\
nd evacuating air.
w Evacuate air and charge proper amount of purified refrigerant after installing th\
e parts in the
refrigerant line.
AC±102
±
AIR CONDITIONING SYSTEM Troubleshooting
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INSTALLATION OF WATER VALVE
1. INSTALL WATER VALVE(a) Push the water hose for the heater unit onto the pipe until the pipe's markings are hidden.
(b) Install the hose clip in a position where about 1 mm (0.039 in.) of the marking on the hose can bee seen.
(c) Install the water valve with two screws.
2. INSTALL FOLLOWING PARTS TO WATER VALVE wConnector
w Vacuum hose
w Water hose
HINT:
w Push the water hose onto the water valve pipe until the
pipe is completely hidden.
w Install the hose clip in a position where about 1 mm
(0.039 in.) of the marking on the hose can bee seen.
AC±128
±
AIR CONDITIONING SYSTEM Water Valve
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GENERAL DESCRIPTION
BR03E±06
1. Care must be taken to replace each part properly as it could affect the \
performance of the brakesystem and result in a driving hazard. Replace the parts with parts of the same part number or
equivalent.
2. It is very important to keep parts and the area clean when repairing the\
brake system.
3. If the vehicle is equipped with a mobile communication system, refer to the precaution \
in the IN section.
DESCRIPTION
BR03F±03
The service brakes consist of a foot brake which changes rotational energy to therma\
l energy to stop the
vehicle while it is being driven and a parking brake to keep the vehicle from m\
oving while it is parked.
OPERATION
FOOT BRAKE
BR03G±06
When the brake pedal is depressed, a vacuum builds up in the booster whi\
ch amplifies the pedal force,
pressing on the piston in the master cylinder. The piston movement raises the hydraulic pressure in the
cylinder. This hydraulic pressure is then applied to each respective brake cylin\
der, and acts to press the
brake pads against the rotating discs. The resulting friction converts the ro\
tational energy to thermal ener-
gy, stopping the vehicle.
BR±2±
BRAKE SYSTEM OPERATION
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GENERAL DESCRIPTION
BR03E±06
1. Care must be taken to replace each part properly as it could affect the \
performance of the brakesystem and result in a driving hazard. Replace the parts with parts of the same part number or
equivalent.
2. It is very important to keep parts and the area clean when repairing the\
brake system.
3. If the vehicle is equipped with a mobile communication system, refer to the precaution \
in the IN section.
DESCRIPTION
BR03F±03
The service brakes consist of a foot brake which changes rotational energy to therma\
l energy to stop the
vehicle while it is being driven and a parking brake to keep the vehicle from m\
oving while it is parked.
OPERATION
FOOT BRAKE
BR03G±06
When the brake pedal is depressed, a vacuum builds up in the booster whi\
ch amplifies the pedal force,
pressing on the piston in the master cylinder. The piston movement raises the hydraulic pressure in the
cylinder. This hydraulic pressure is then applied to each respective brake cylin\
der, and acts to press the
brake pads against the rotating discs. The resulting friction converts the ro\
tational energy to thermal ener-
gy, stopping the vehicle.
BR±2±
BRAKE SYSTEM OPERATION
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