Lexus SC300 / Lexus SC400. Manual - part 12

Handling Precautions for Gas–Cylinder
Type Gas Leak Tester

1. 

BEFORE USING TESTER MAKE SURE THAT THERE
ARE NO FLAMMABLE SUBSTANCES NEARBY

2. 

BE CAREFUL NOT TO INHALE POISONOUS GAS
If refrigerant gas comes in contact with flame, a poisonous
gas is prodused. During leak tests, do not inhale any gas.

Precautions When Replacing Parts in
Refrigerant Line

1. 

RECOVER REFRIGERANT IN SYSTEM BEFORE
REMOVING PARTS
Using a recovery machine, recover refrigerant in system be-
fore removing the parts.
NOTICE: Do not release refrigerant to atmosphere.

2. 

INSERT PLUG IMMEDIATELY IN DISCONNECTED
PARTS
Insert a plug immediately in the disconnected parts to pre-
vent the entry of moisture and dust.

3. 

DO NOT REMOVE PLUG FROM NEW PARTS UNTIL
IMMEDIATELY BEFORE INSTALLATION

4. 

DO NOT USE BURNER FOR BENDING OR
LENGTHENING OPERATIONS ON TUBE

If the tubes are heated with a burner, a layer of oxidation
forms inside the tube, causing the same kind of trouble as an
accumulation of dust.

5. 

DISCHARGE GAS IN NEW COMPRESSOR FROM
CHARGING VALVE BEFORE INSTALLING IT
If the gas in new compressor is not discharged first, compres-
sor oil will spray out with gas when the plug is removed.

6. 

TIGHTEN CONNECTING PARTS SECURELY
Securely tighten the connecting parts to prevent leaking of
refrigerant gas.

•

Apply a few drops of compressor oil to O–ring fittings for
easy tightening and to prevent leaking of refrigerant
gas.

•

Tighten the nuts using two wrenches to avoid twisting
the tube.

AC–4

–

AIR CONDITIONING SYSTEM

General Description

•

Tighten the O–ring fittings or the bolted type fittings to
the specified torque.

Precautions When Charging Refrigerant

1. 

DO NOT OPERATE COMPRESSOR WITHOUT ENOUGH
REFRIGERANT IN REFRIGERANT CYCLE
If there is not enough refrigerant in the refrigerant cycle, oil
lubrication will be insufficient and compressor burnout may
occur, so take care to avoid this.

2. 

DO NOT OPEN HIGH PRESSURE VALVE OF MANIFOLD
GAUGE WITH COMPRESSOR OPERATING
If the high pressure valve is opened, refrigerant flows in the
reverse direction and could cause the charging cylinder to
rupture, so open and close the low pressure valve only.

3. 

BE CAREFUL NOT TO OVERCHARGE WITH
REFRIGERANT IN SYSTEM
If refrigerant is overcharged, it causes trouble such as insuffi-
cient cooling, poor fuel economy, engine overheating etc.

Electrical Parts

Before removing and inspecting the electrical parts, set the
ignition switch to the LOCK position and disconnect the neg-
ative (–) terminal cable from the battery.
CAUTION: Work must not be started until after at least 20
seconds or longer from the time the negative (–) terminal
cable is disconnected.

SRS Airbag System

Failure to carry out service operations in the correct se-
quence could cause the airbag system to deploy, possibly
leading to a serious accident.
When removal or installation of the parts and the yellow wire
harness and connector for the airbag is necessary, refer to
the precautionary notices in the AB section before perform-
ing the operation.

–

AIR CONDITIONING SYSTEM

General Description

AC–5

DESCRIPTION

FEATURES

The microprocessor controlled automatic air conditioner is a system which controls the the cabin air conditioning
automatically using a microcomputer.
The microcomputer senses the air temperature outside and inside the cabin, the amount of sunlight, the com-
pressor operating condition and temperature setting, etc. and maintains the optimum blower air temperature
and air flow at the intakes and outlets automatically.

PARTS LOCATION

AC–6

–

AIR CONDITIONING SYSTEM

Description

PARTS LOCATION (Cont’d)

–

AIR CONDITIONING SYSTEM

Description

AC–7