Isuzu N-Series. Manual - part 544

6F-6   Exhaust System

Torque Specifications

N6A6434E

Exhaust System   6F-7

Exhaust System

Service Precautions

Offset in position of the exhaust system during
assembly may sometimes cause vibrations or rattling
noise. Therefore, temporarily tighten the bolts until all
the parts have been positioned, and sequentially
tighten from the engine side to the rear pipe side.

Explanations on Functions and Operation

The exhaust brake assembly operates the auxiliary
brakes by adjusting the exhaust pressure. The tail pipe
has a built-in post silencer. (S-spec only) This improves
the silencing effect.
The main parts consist of the front exhaust pipe, center
exhaust pipe, exhaust brake unit, silencer, extension
pipe, and tail pipe.

Legend

1. Front Exhaust Pipe A
2. Exhaust Brake Assembly
3. Front Exhaust Pipe B

4. Silencer
5. Extension Pipe
6. Tail Pipe

 

Functional Check

• During check or repairs of the exhaust system,

confirm that the clearance between the body and
the floor is adequate.

• Adequate care should be taken to prevent damage

due to heating or vibrations in the body panel as it
may lead to exhaust gas entering the cabin.

• Check for loose or damaged connectors and

leakage of exhaust gas.

• Check for degradation, cracks or damage to the

clamp or rubber.

• If the pipe or silencer is damaged or has a dent

then repair or replace it.

• Check for dents, damage, holes or cracks due to

corrosion, and abnormal noise during operation.

List of Abnormal Phenomena

• Vibration or rattling noise from the exhaust system
• Clogging of the exhaust system
• Exhaust leakage or noise

1

2

3

6

4

5

N6A6435E

6F-8   Exhaust System

Trouble Shooting

Vibration or rattling noise from the exhaust system

Clogging of the exhaust system

Exhaust leakage or noise

Condition

Possible Cause

Correction

Vibration or rattling noise from the
exhaust system

Loose or misaligned components

Match the joints and then re-tighten.
Or, check for damage in the hanger,
mounting brackets and clamps.

Condition

Possible Cause

Correction

Clogging of the exhaust system

The exhaust brake is in the ON
status.

Refer to Section 6E, check the
electric system and repair if there
are abnormalities.
Check if the shaft movement in the
exhaust brake throttle valve moves
is jerky and replace if there is an
abnormality.

Clogging or deformation of the
exhaust piping

Repair or replace the exhaust
piping.

Condition

Possible Cause

Correction

Exhaust leakage or noise

Defect or misalignment in mounting

Match the joints and then re-tighten.

Damage or burn-out of exhaust
piping or silencer

Replace the damaged parts.

Defective components in the
exhaust system (clamps, pipes,
silencer)

Replace the defective parts.

Internal damage to silencer

Replace the silencer.

Exhaust System   6F-9

Exhaust Pipe

Removal

1. Remove the silencer fixing nut.
2. Remove the silencer brackets.
3. Remove the silencer.
4. Remove the front exhaust pipe B.
5. Remove the exhaust brake assembly.
6. Remove the front exhaust pipe A.

• Remove the clamps and then the front exhaust

pipe.

Inspection

• Adequate care should be taken to prevent damage

due to heating or vibrations in the body panel as it
may lead to exhaust gas entering the cabin.

• Check for loose or damaged connectors and

leakage of exhaust gas.

• Check for degradation, cracks or damage to the

clamp or rubber.

• Check for dents in the pipes or silencer and also

for cracks due to corrosion, and repair or replace in
case of damage.

Installation

Caution:

• Offset in the position of the exhaust system during

assembly may sometimes cause vibrations or
rattling noise. Therefore, temporarily tighten the
bolts until all the parts have been positioned and
then tighten sequentially from engine side to the
tail pipe side.

• Do not reuse the removed gasket or nuts.

1. Mount the front exhaust pipe A.

• Assemble the gasket, mount the front exhaust

pipe in the turbo charger, and tighten to the
specified torque.

Tighten:
Nut to 67 N

⋅m (6.8 kg⋅m/49 lb⋅ft)

• Clamp the front exhaust pipe.

Tighten:
M10 bolt to 41 N

⋅m (4.2 kg⋅m/30 lb⋅ft)

Caution:
Tighten the front exhaust pipe evenly and take care to
avoid gas leakage.

2. Mount the exhaust brake assembly.

• Assemble the gasket, connect the front exhaust

pipe and the front exhaust pipe B, and tighten.

Tighten:
Bolt to 17 N

⋅m (1.7 kg⋅m/12 lb⋅ft)

3. Mount the silencer.

• Assemble the gasket, mount to the front

exhaust pipe B, and tighten to the specified
torque.

Tighten:
Nut to 24 N

⋅m (2.4 kg⋅m/17 lb⋅ft)

4. Mount the silencer brackets.

• Mount the silencer in the brackets.

Tighten:
Nut to 34 N

⋅m (3.5 kg⋅m/25 lb⋅ft)

N6A6436E

N6A6437E