Isuzu KB P190. Manual — part 337

EXHAUST SYSTEM 6F – 15

TURBOCHARGER

MAIN DATA AND SPECIFICATIONS

Engine 4JA1T(L)

4JA1TC

4JH1TC

Model

IHI RHF4H

IHI RHF4H

IHI RHF5

Turbine type

Mixed type

Compressor type

Backword & rake type

Maximum permissible speed rpm

190,000

190,000

180,000

IHI : Ishikawajima Harima Heavy Industries., Ltd.

6F – 16 EXHAUST SYSTEM

GENERAL DESCRIPTION

036LV002

The turbocharger internal mechanism consists of the turbine wheel, the compressor wheel, and the radial bearings.
These parts are supported by the bearing housing.

The turbocharger external mechanism consists of the compressor housing air intake port and the turbine housing
air exhaust port.

The turbocharger increases air intake efficiency. This results in increased engine power, reduced fuel consumption,
and minimal engine noise.

The turbocharger operates at very high speeds and temperatures. Part materials have been carefully selected and
machined to extremely high precision.

Turbocharger servicing requires great care and expertise.

If reduced performance is noted, check the engine for damage or wear. If there is no apparent engine damage or
wear, trouble with the turbocharger is indicated.

EXHAUST SYSTEM 6F – 17

INSPECTION AND REPAIR

Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during
inspection.

Turbocharger pressure check

1. Remove the hose between the waste gate and the

compressor outlet pipe.

2. Connect the pressure gauge. To compressor outlet

pipe.

3. Start the engine and gradually increase the engine

speed (the vehicle must be stationary with no load
applied to the engine).

4. Check to see that turbocharger pressure rises to

approximately 141.3 Kpa (1060 mmHg).
Pressure Gauge : 5-8840-0075-0

150RY00030

Waste gate operation check

1. Remove the hose between the waste gate and the

compressor outlet pipe.

2. Connect the pressure gauge. To waste gate actuator.

3. Check to see that the rod begins to move when a

pressure of approximately 118 Kpa (885 mmHg) is
applied to the waste gate.

Note:

Do not apply a pressure greater than 150Kpa (1125
mmHg) to the waste gate during this check.

150RY00031

Unit Inspection (Remove Turbo. from engine)

Check to see the pressure required to move the control
rod 2 mm is within the limits shown below.

Kpa/mmHg

4JH1TC 134.8/1011

4JA1TC 147.7/1108

150RY00032

Contact the “ISUZU MOTORS LIMITED” Dealer service
department or “IHI SERVICE FACILITY” for major repairs
and maintenance.

Important wheel shaft end play and bearing clearance
standards and limits are included below for your reference.

6F – 18 EXHAUST SYSTEM

Wheel Shaft End Play

Use a dial indicator to measure the wheel shaft end play.
Apply a force of 1.2 kg (2.6 lb/11.8N) alternately to the
compressor wheel end and the turbine wheel end.

Wheel Shaft End Play

mm (in)

Standard Limit

0.03 - 0.06

(0.001 - 0.002)

0.09 (0.004)

150RY00034

Wheel Shaft and Bearing Clearance

Use a dial indicator to measure the wheel shaft and
bearing clearance.

Wheel Shaft and Bearing Clearance

mm (in)

Standard Limit

0.056 - 0.127

(0.0022 - 0.0050)

0.127 (0.0050)

150RY00036