Isuzu KB P190. Manual - part 379

6A-156  ENGINE MECHANICAL (4JK1/4JJ1) 

Oil Pump 

Components 

 

 

 

 

 

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 1. Bolt 

 

 2. Oil 

Pump 

Assembly 

 

Removal 

1.  Drain the engine coolant. 

2.  Remove the radiator upper hose. 

3.  Remove the upper fan shroud. 

4.  Remove the fan and fan clutch. 

•  Loosen the fan clutch nuts. 
•  Remove the fan together with the fan clutch.

Take care not to damage the radiator core. 

5.  Remove the fan drive belt and pulley. 

•  Loosen the tension adjust bolt on the generator

and A/C. 

•  Remove the fan drive belt with the fan pulley. 

6.  Remove the lower fan shroud. 

7.  Disconnect the power steering pump. 

•  Disconnect the bracket of the power steering oil

hose clip (1). 

 

 

 

 

 

 

 

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ENGINE MECHANICAL (4JK1/4JJ1)  6A-157 

8.  Remove the vacuum pump. 

•  Remove the vacuum pipe bracket and vacuum

pipe. 

•  Remove the oil pipe (feed side and return side)

of vacuum pump. 

9.  Remove the noise cover (1). 

 

 
 
 

 

 

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10.  Remove the crank pulley. 

11.  Remove the front cover. 

 

 

 

 

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12. Remove the oil pump (1). 

 

 

 

 

 

 

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Disassembly 

1.  Remove the spring pin. 

2.  Remove the spring seat. 

3.  Remove the spring. 

4.  Remove the valve. 

 

6A-158  ENGINE MECHANICAL (4JK1/4JJ1) 

Reassembly 

1.  Install the valve.  

2.  Install the spring. 

3.  Install the spring seat. 

4.  Install the spring pin. 

 

 
 
 
 
 

 

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Legend 

 1. Spring 

Pin 

 2. Spring 

Seat 

 3. Spring 

 4. Valve 

 

Inspection 

NOTE:  
Think to match direction of ditch of gear when
assembling it. 

1. Measure the clearance between the driven

gear/drive gear shaft and the bush. 
•  Measure the outside diameter of the driven

gear shaft using a micrometer. 

  Outside diameter of the driven gear shaft/drive 

gear shaft 

mm (in)

Standard 

15.989 - 16.000 (0.62949 - 0.62992) 

Limit 15.900 

(0.62598) 

 

 

 

 

 

 

 

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•  Measure the inside diameter of the bushes of 

the cylinder block using the dial gauge. 

•  If the clearance between the driven gear 

shaft/drive gear shaft and bush exceeds the 

limit, replace the oil pump assembly. 

  Clearance between the driven gear shaft/drive gear 

shaft and bush 

mm (in)

Standard 

0.04 - 0.07 (0.0016 - 0.0028) 

Limit 0.20 

(0.0079) 

 
 

 

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2. Measure the clearance between the gear side 

surface and the gear side surface of the oil pump 

housing. 
•  Measure the width size the driven gear/drive 

gear. 

  Width size the driven gear/drive gear 

mm (in)

Standard 14.5 

(0.5709) 

 

ENGINE MECHANICAL (4JK1/4JJ1)  6A-159 

 
  

 

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•  Measure the Depth size of the gear case

housing surface and the oil pump housing gear

case side. 

  Depth size the gear case housing surface and the oil 

pump housing gear case side 
 mm 

(in)

Standard 

14.500 - 14.527 (0.5709 - 0.5719) 

 
  

 

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  Clearance between the gear side surface and the 

gear side surface of the oil pump housing 

mm (in)

Standard 

0.063 - 0.027 (0.0025 - 0.0011) 

Limit 0.20 

(0.0079) 

 

 

Installation 

1.  Install the oil pump. 

•  Apply engine oil to the oil pump attachment 

gearbox. 

•  Tighten the bolts to the specified torque. 

Tightening torque: 25 N

⋅⋅⋅⋅m (2.5 kg⋅⋅⋅⋅m / 18 lb ft) 

•  Installed pump gear should be smooth to 

rotate. 

2.  Install the gear case cover. 

•  Apply the liquid gasket (Threebond TB-1207B 

or equivalent) mount within 5 minutes. 

 

 

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Legend 

  1.  Apply the liquid gasket in area