Isuzu KB P190. Manual — part 381

ENGINE COOLING (4JK1/4JJ1) 6B-1

SECTION 6B

ENGINE COOLING

TABLE OF CONTENTS

Main Data and Specifications. . . . . . . . 6B-2

General Description. . . . . . . . . . . 6B-3

Coolant Flow . . . . . . . . . . . . ... 6B-3

Water Pump . . . . . . . . . . . . . 6B-4

Thermostat . . . . . . . . . . . . . .. 6B-4

Radiator. . . . . . . . . . . . . . ... 6B-5

Antifreeze Solution . . . . . . . . . . .. 6B-5

Diagnosis. . . . . . . . . . . . . . . 6B-6

Draining and Refilling Cooling System . . . ... 6B-7

Water Pump . . . . . . . . . . . . . ... 6B-8

Removal . . . . . . . . . . . . . . .. 6B-8

Inspection and Repair . . . . . . . . . . 6B-9

Installation . . . . . . . . . . . . . ... 6B-9

Thermostat . . . . . . . . . . . . . . . 6B-11

Removal . . . . . . . . . . . . . . .. 6B-11

Inspection and Repair . . . . . . . . . . 6B-11

Operating Test of Thermostat . . . . . . . 6B-11

Installation . . . . . . . . . . . . . ... 6B-12

Radiator. . . . . . . . . . . . . . . .. 6B-13

Radiator and Associated Parts. . . . . . 6B-13

Removal . . . . . . . . . . . . . . .. 6B-14

Inspection and Repair . . . . . . . . . . 6B-15

Radiator Cap . . . . . . . . . . . . ... 6B-15

Radiator Core. . . . . . . . . . . . .. 6B-15

Flushing the Radiator . . . . . . . . . .. 6B-15

Cooling System Leakage Check . . . . . . 6B-15

Installation . . . . . . . . . . . . . ... 6B-16

Engine Coolant Change . . . . . . . . .. 6B-16

Fan Clutch with Cooling Fan . . . . . . . .. 6B-17

Inspection and Repair . . . . . . . . . . 6B-17

Special Tools. . . . . . . . . . . . ... 6B-18

6B-2 ENGINE COOLING (4JK1/4JJ1)

Main Data and Specifications

Description

Item

M/T A/T

Cooling system

Water pump type

Pump to crankshaft speed ratio

(To 1)

Delivery volume

lit (US/UK gal)/min

Pump speed at 5600 rpm

Water temperature at 30

°C (86°F)

Pump bearing type

Thermostat type

Valve initial opening temperature

°C (°F)

Valve full opening temperature

°C (°F)

Valve lift at fully open position

mm (in)

Engine coolant forced circulation

Centrifugal impeller type

1.25

240 (63.1/53.3)

Double row shaft

Wax pellet with jiggle valve

85 (185)

100 (212)

10 (0.39)

Radiator

Tube type corrugated

Heat radiation capacity

kW (kcal/h)

93 (80.2)

Heat radiation area

m

2

(ft

2

) 11.63

(125.2)

Radiator front area

m

2

(ft

2

) 0.28

(3)

Radiator dry weight

N (kg/lb)

52

53

Radiator cap valve opening pressure kPa (kg/cm

2

/psi)

93.3 - 122.7 (0.95 - 1.25/13.5 - 17.8)

Engine coolant capacity

lit (U.S pint)

4.0 (8.5)

4.0 (8.5)

Engine coolant total capacity

lit (U.S pint)

8.7 (18.4)

8.6 (18.2)

ENGINE COOLING (4JK1/4JJ1) 6B-3

General Description

Coolant Flow

RTW76BLF000301

The engine cooling system consists of the radiator, the
water pump, the cooling fan, and the thermostat.

To quickly increase cold engine coolant temperature for
smooth engine operation, the coolant is circulated by
the water pump and thermostat through the bypass pipe
and back to the cylinder body.

The coolant does not circulate through the radiator.

When the coolant temperature reaches the specified
value, the thermostat will begin to open and a gradually
increasing amount of coolant will circulate through the
radiator.

The thermostat will be fully open when the coolant
temperature reaches the specified value. All of the
coolant is now circulating through the radiator for
effective engine cooling.

6B-4 ENGINE COOLING (4JK1/4JJ1)

Water Pump

RTW56BSF000101

A centrifugal type water pump forcefully circulates the
coolant through the cooling system.

The water pump is not a disassembled type.

Thermostat

RTW56BSF000201

A wax pellet type thermostat is used.