Lexus RX300 (MCU15). Manual — part 4

INTRODUCTION

– Handling Precautions on Related Components

IN-9

3.

BRAKE SYSTEM

The brake system is one of the most important safety components. Always follow the directions and
notes given in section BR of the repair manual for the relevant model year when handling brake sys-
tem parts.

NOTICE:

When repairing the brake master cylinder or TRAC system, bleed the air out of the TRAC

system.

4.

DRIVE TRAIN AND CHASSIS

The drive train and chassis are components that can have great effects on the running performance
and vibration resistance of the vehicle. After installing components in the sections listed in the table
below, perform alignments to ensure correct mounting angles and dimensions. Particularly accurate
repair of the body must also be done to ensure correct alignment.

HINT:

Correct procedures and special tools are required for alignment. Always follow the directions

given in the repair manual for the relevant model year during alignment and section DI of this manual.

Component to be aligned

Section of repair manual

for relevant model year

Front Wheels

Suspension and Axle (SA) section

Rear Wheels

Suspension and Axle (SA) section

Propeller Shaft

Propeller Shaft (PR) section

5.

ECU (ELECTRONIC CONTROL UNIT)

Many ECUs are mounted in this vehicle.
Take the following precautions during body repair to prevent damage to the ECUs.
D

Before starting electric welding operations, disconnect the negative (–) terminal cable from the bat-
tery.
When the negative (–) terminal cable is disconnected from the battery, memory of the clock and audio
systems will be cancelled. So before starting work, make a record of the contents memorized by each
memory system. Then when work is finished, reset the clock and audio systems as before.
When the vehicle has tilt and telescopic steering, power seat and outside rear view mirror, which are
all equipped with memory function, it is not possible to make a record of the memory contents.
So when the operation is finished, it will be necessary to explain this fact to the customer, and request
the customer to adjust the features and reset the memory.

D

Do not expose the ECUs to ambient temperatures above 80

_C (176_F).

NOTICE:

If it is possible the ambient temperature may reach 80

_ (176_F) or more, remove the ECUs

from the vehicle before starting work.

D

Be careful not to drop the ECUs and not to apply physical shocks to them.

INTRODUCTION –

General Repair Instructions

IN-10

SAFETY
Never stand in direct
line with the chain
when using a puller on
the body or frame, and
be sure to attach a
safety cable.

VEHICLE PROTECTION
When welding, protect the
painted surfaces,windows,
seats and carpet with heat-
resistant, fire-proof covers.

SAFETY
1. Before performing repair work, check

for fuel leaks. If a leak is found, be
sure to close the opening totally.

2. If it is necessary to use a frame in the

area of the fuel tank, first remove the
tank and plug the fuel line.

HAND TOOLS
Keeping your hand tools
in neat order improve
your work efficiency.

SAFETY WORK CLOTHES
In addition to the usual mechanic’s wear, cap and safety shoes,
the appropriate gloves, head protector, glasses, ear plugs, face
protector, dust-prevention mask, etc. should be worn as the
situation demands.

WRONG

Glass Cover

Safety Cable

Seat Cover

WRONG

Dust-
Prevention
Mask

Body
Tools
Stand

Face
Protector

Eye
Protector

Safety
Shoes

Welder’s
Glasses

Ear
Plugs

Head
Protector

Welder’s
Gloves

GENERAL REPAIR INSTRUCTIONS

Work Precautions

INTRODUCTION –

General Repair Instructions

IN-11

PRE-REMOVAL MEASURING
Before removal or cutting
operations, take measurements
in accordance with the dimen-
sion diagram. Always use a
puller to straighten a damaged
body or frame.

NUMBER OF SPOT WELDS AND PANEL POSITIONS
The number of spot welds and the panel positions
to be removed are shown for your reference.
HINT:

See ”Symbols” on page IN-4,5.

REMOVAL OF ADJACENT COMPONENTS
When removing adjacent components,
apply protective tape to the surrounding
body and your tools to prevent damage.
HINT:

See ”Handling Precautions on

Related Components” on page IN-6.

PRECAUTIONS FOR DRILLING OR
CUTTING
Check behind any area to be drilled or
cut to insure that there are no hoses,
wires, etc., that may be damaged.
HINT:

See ”Handling Precautions on

Related Components” on page IN-6.

CUTTING AREA
Always cut in a straight
line and avoid reinforced area.

WRONG

Cutting Okay

Reinforcement

Corners

Proper and Efficient Work Procedures

REMOVAL

INTRODUCTION –

General Repair Instructions

IN-12

When welding panels with
a combined thickness of
over 3 mm (0.12in.), use a
MIG (Metal Inert Gas)
welder for plug welding.
HINT:

Spot welding will

not provide sufficient
durability for panels over
3 mm (0.12in.) thick.

Remove the paint
from the portion of
the new parts and
body to be welded,
and apply weld-
through primer.
HINT:

See ”ANTI-

RUST TREATMENT”
on page AR-2.

ROUGH CUTTING OF
JOINTS
For joint areas, rough
cut the new parts,
leaving 20 – 30 mm
(0.79 – 1.18in.) overlap.

MAKING HOLES FOR PLUG WELDING
For areas where a spot welder cannot
be used, use a puncher or drill to make
holes for plug welding.

SAFETY PRECAUTIONS FOR
ELECTRICAL COMPONENTS.
When welding there is a dan-
ger that electrical compo-
nents will be damaged by the
electrical current flowing
through the body.
Before starting work discon-
nect the negative terminal of
the battery and ground the
welder near the welding loca-
tion of the body.

Less than
3 mm

Overlap

Air Saw

Puncher

20 – 30 mm

Parts Name

Parts Number

Spot Sealer

08839-00070

The above SSM
or equivalent

PREPARATION FOR INSTALLATION

SPOT WELD POINTS

APPLICATION OF WELD-THROUGH PRIMER
(SPOT SEALER)

REFERENCE:

mm (in.)

Thickness of

Size of plug hole

welded portion

Size of plug hole

1.0 (0.04) under

5 (0.20) ø over

1.0 (0.04) – 1.5 (0.06)

6.5 (0.26) ø over

1.5 (0.06) over

8 (0.31) ø over