300.9D VPS Mini Hydraulic Excavator Machine Systems Fuel Injection Nozzle - Test Caterpillar

Testing the Injection Nozzles

1. Remove the injection line and the injection nozzle.
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   Illustration 1	g02481897
   Nozzle tester

2. Connect the injection nozzle to the high-pressure line of the nozzle tester.

3. Slowly increase the pressure until the nozzle ejects fuel. Use the pressure gauge to determine the pressure.

4. If the injection pressure is lower than 118 - 128 bar (1711 - 1856 psi), then replace the spacer in the nozzle with a thicker spacer. If the injection pressure is higher than 118 - 128 bar (1711 - 1856 psi), then replace the spacers in the nozzle with a thinner spacer.

   Spacer thickness of 0.1 mm (0.004 inch) corresponds to a modification of 6.9 - 9.8 bar (100 -142 psi).

5. Check the injection nozzle for drips after fuel has been injected.

6. Create a pressure of approximately 20 bar (290. psi) below the recommended injection pressure range. Check for fuel escaping the nozzle.

Checking the Nozzle Jet

1. Remove the injection lines and the injection nozzles.

2. Connect the injection nozzle to the high-pressure line of the nozzle tester.

3. Quickly increase pressure until the nozzle ejects fuels 3 or 4 times.
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   Illustration 2	g02481998
   Correct shape of nozzle jet spray.

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   Illustration 3	g02482438
   Incorrect shapes of nozzle jet spray.

4. Hold a white sheet of paper approximately 30 cm (12 inch) away form the nozzle. Eject fuel and observe the shape of the spray.