Isuzu KB P190. Manual - part 528

6B-8  ENGINE COOLING 

 
 
 
 

 

 
 
 

 

 
 

•  Crack in the water pump body 
•  EC leakage from the seal unit 
•  Play or abnormal noise in the bearing 
•  Cracks or corrosion in the impeller 

Installation 

1. Before installing water pump, coat sealing surface with

silicon grease. 

2. Install water pump assembly and tighten bolts to the

specified torque. 

 

Torque: 25 N

⋅⋅⋅⋅m (2.5 kgf⋅⋅⋅⋅m) 

3. Timing belt 

•  Install timing belt, refer to timing belt installation step in

"Timing Belt" in this manual. 

4.  Connect radiator hose and replenish EC. 

5.  Connect battery ground cable. 

 

ENGINE COOLING  6B-9 

Thermostat 

 
 

 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 

 

 
 
 
 
 
 

Removal 

1.  Disconnect battery ground cable. 

2.  Drain engine coolant from the radiator and engine. 

3.  Disconnect radiator hose from the inlet pipe. 

4.  Remove thermostat housing. 

5.  Remove thermostat from thermostat housing. 

Inspection 

Suspend the thermostat in a water-filled container using thin 
wire. Place a thermometer next to the thermostat. 
Do not directly heat the thermostat. 
Gradually increase the water temperature. Stir the water so 
that the entire water is same temperature. 
Confirm the temperature when the valve first begins to open. 

  Valve opening temperature 92

°°°°C (197.6°°°°F) 

Confirm the temperature when the valve is fully opened. 

  Valve full open temperature 107

°°°°C(224.6°°°°F) 

Make necessary repair and parts replacement if extreme wear 
or damage is found during inspection. 

Installation 

1. Before installing thermostat, coat sealing surface with 

silicon grease. 

2. Install O-ring. 

3.  Install thermostat housing and tighten bolts to the specified

torque. 

 

Torque: 15 N

⋅⋅⋅⋅m (1.5 kgf⋅⋅⋅⋅m) 

4.  Installation rubber hose. 

5.  Replenish engine coolant (EC). 

6.  Start engine and check for EC leakage. 

 

 

 

 

 

 

 

 

 

 
 
 
 
 

Fan Clutch with Cooling Fan 

Inspection and Repair 

Make necessary correction or parts replacement if wear, 

damage or any other abnormal condition are found through 

inspection. 

 

Visually inspect for damage, leak (silicon grease) or other 

abnormal conditions. 

1. Inspection (on-vehicle) 
  1)  Turn the fan clutch by hand when in a low temperature 

condition before starting the engine, and confirm that it 
can be turned readily. 

  2)  Start the engine to warm it up until the temperature at the 

fan clutch portion gets to around 80

°C. Then stop the 

engine and confirm that the fan clutch can be turned with 
considerable effort (clutch torque) when turned by hand.
 

6B-10  ENGINE COOLING 

   

If the fan clutch rotates more readily, however, this 
indicates that the silicon grease is leaking internally. 
Replace the fan clutch with a new one. 

 

2.  Inspection (in unit) 

 

Warm up the bimetal of the fan clutch by using the heat gun

until the temperature gets to about 80

°C when measured 

with the thermistor. Then confirm that the fan clutch can be

turned with considerable effort (clutch torque). 

  If the fan clutch retates more readily at this time, this

indicates that the silicon grease is leaking internally. 

 

Replace the fan clutch with a new one. 

 

ENGINE COOLING  6B-11 

Radiator 

Radiator and Associated Parts 

 
 

 

Legend 

1 Radiator Hose 
2 Drain Plug 
3 Fan Guide, Lower 
4 Fan Guide 
5 Bracket 

6 Reserve Tank Hose 
7 Reserve Tank 
8 Radiator Cap 
9 Radiator Assembly 

 

 

 

Removal 

1.  Disconnect battery ground cable. 

2.  Loosen a drain plug to drain engine coolant (EC). 

3.  Disconnect radiator inlet hose and outlet hose. 

4.  Disconnect the reserve tank hose from radiator. 

5.  Lift out the radiator assembly, taking care not to damage

the radiator core.