Test Sequence for Capsule Type Fuel Nozzles{0782} Caterpillar

Machine Engines: 3304 3306 3406

Engine:

1673 (S/N: 70B1-UP)

1673C (S/N: 76R1-UP)

3306 (S/N: 23C740-UP)

3406 (S/N: 90U1-UP; 91U1-UP; 92U1-UP)

3408 (S/N: 28V1-4749; 67U1-UP; 78Z1-1143; 99U1-4603)

3408B (S/N: 28V4750-UP; 60M1-5160; 78Z1144-4866; 99U4604-7598)

3408C (S/N: 60M5161-UP; 78Z4867-UP; 99U7599-UP)

3412 (S/N: 38S1-UP; 81Z1-UP)

D320 (S/N: 63B1-UP)

D330 (S/N: 82B1-UP)

D330A (S/N: 57B1-UP; 86B1-UP)

D330C (S/N: 02B1-UP; 04B1-UP; 05B1-UP)

D333 (S/N: 59B1-UP; 80B1-UP)

D333C (S/N: 23C1-739; 66D1-UP; 67D1-UP)

D342 (S/N: 31B1-UP; 32B1-UP)

D342C (S/N: 49B1-UP; 50B1-UP)

D353 (S/N: 46B1-UP)

D353C (S/N: 47B1-UP)

D379 (S/N: 68B1-674; 69B1-823)

D379B (S/N: 34Z1-UP; 68B675-UP; 69B824-UP)

D398 (S/N: 66B1-2048; 67B1-919)

D398B (S/N: 35Z1-UP; 66B2049-UP; 67B920-UP)

D399 (S/N: 35B1-UP; 91B1-UP; 36Z1-UP)

Introduction

This Special Instruction has been written in order to provide procedural information for testing capsule type fuel nozzles.

There is an extensive amount of information that relates to the setup and the calibration of the tools that will be used to test the fuel nozzles.

Additionally, there is information on the setup and operation of the cleaning equipment that is necessary in order to properly clean the fuel nozzles.

There is also a publication that provides record sheets. These record sheets can be used for recording and correlating the test data that is accumulated. The following information will summarize the related documentation.

• For information on the setup, operation, and the calibration of the test equipment, refer to Tool Operating Manual, SEHS7292, "Using the 5P-4150 Nozzle Testing Group".

• For information that relates to the setup and operation of the tools that are used to clean fuel nozzles, refer to Special Instruction, SEHS8627, "Using the 8S-2245 Nozzle Cleaning Tool Group".

• Use the Special Instruction, SEHS8144, "Engine Nozzle Test Record" in order to record the results while you are testing each fuel nozzle. These record sheets are available through normal channels for literature distribution. The record sheets are available in pads that contain 50 sheets.

Note: The publications that are mentioned above may contain information that must be referenced in order to test the fuel injection nozzles.

Testing Capsule Type Fuel Nozzles

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Ensure that you wear eye protection at all times during testing. When fuel injection nozzles are tested, test fluids travel through the orifices of the nozzle tip with high pressure. Under this amount of pressure, the test fluid can pierce the skin and cause serious injury to the operator. Always keep the tip of the fuel injection nozzle pointed away from the operator and into the fuel collector and extension.

Note: Prior to starting this test procedure, the 5P-4150 Nozzle Testing Group must be equipped with a 8T-0860 Pressure Gauge . Replace the original 8T-0859 Pressure Gauge with the 8T-0860 Pressure Gauge . Refer to Tool Operating Manual, SEHS7292, "Using the 5P-4150 Nozzle Testing Group" for information that relates to the replacement of the pressure gauge.

Visual Inspection of the Fuel Nozzle

Perform a visual inspection of the fuel nozzle. Inspect each fuel nozzle for any sign of damage that may contribute to the improper operation of the fuel nozzle. Check for signs of damage that may have been caused by any of the following conditions:

• Engine overheating (discolored fuel nozzles)

• Improper cleaning (use of a wire brush for cleaning)

• Fuel nozzles that are deformed or bent

• Cracking or splitting of the nozzle tip

• Damage to the fuel nozzle's inlet screen

• Other obvious damage

Note: If there are signs of engine overheating, all of the fuel nozzles must be replaced.

If any of these forms of damage has been found, do not use the damaged fuel nozzle.

Install the Fuel Nozzle onto the Test Fixture

Note: Use the 5P-8744 Adapter and the 5P-4721 Tube to test capsule type fuel nozzles for precombustion chamber engines and for direct injection engines. Be sure to check the test fixture for leaks prior to performing this test procedure. Refer to Tool Operating Manual, SEHS7292, "Using the 5P-4150 Nozzle Testing Group" for information that is related to the operation of the nozzle testing group.

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Illustration 1	g00943801

1. Position the fitting (1) of the adapter assembly (2) onto the tube assembly (3) and tighten the fitting.

2. Install the fuel nozzle into the valve holder of the adapter assembly.

3. Close the ON/OFF valve on the test stand.

4. Open the pump isolator valve for one-half turn.

5. Place the 8S-2270 Fuel Collector and the 1U-8857 Extension Tube under the fuel nozzle.

Bleed the Air from the Nozzle Assembly

1. Open the gauge protector valve that is appropriate for the type of fuel nozzle that is being tested.
   • For precombustion chamber fuel systems, open the gauge protector valve (0 to 6000 kPa (0 to 870 psi) gauge) for one-half of a turn.

   • For direct injection fuel systems, open the gauge protector valve (0 to 40,000 kPa (0 to 5,800 psi) gauge) for one-half of a turn.

2. Loosen the fitting on the bottom part of the valve holder for one-half turn.

3. Operate the pump handle until test fluid that is free of air bubbles flows from the threads of the adapter.

4. Tighten the fitting on the bottom part of the valve holder.

Pressure Loss Test

Note: In order to obtain test results that are consistent, check the test fixture for leakage prior to performing this test. Check for leaks at each fitting and at the adapter assembly. Repair any leaks that are discovered.

For precombustion chamber fuel systems, use this procedure:

1. Open the gauge protector valve (0 to 6,000 kPa (0 to 870 psi) gauge) for an additional one-half of a turn.

2. Pump the tester until a pressure of 2,070 kPa (300 psi) is attained on the pressure gauge. Close the pump isolator valve.

   Note: The pump isolator valve should be used to adjust the tester to the correct test pressure. Do not place excessive pressure on the nozzle assembly during this test.

3. Record the pressure loss that occurs during a 30 second time interval. Open the pump isolator valve in order to release the pressure on the fuel nozzle when the test is completed.

   Compare the test results to the specifications that are in Table 1.

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   Table 1

   Specifications for Pressure Loss Precombustion Chamber Fuel Systems
   Nozzle pressure must not drop below a gauge reading of 690 kPa (100 psi) during a 30 second time interval.

Illustration 2	g00933420

If the fuel nozzle is not within specifications, stop the test and do not use the fuel nozzle.

For direct injection fuel systems, use this procedure:

1. Open the gauge protector valve (0 to 40,000 kPa (0 to 5800 psi) gauge) for an additional one-half of a turn.

2. Pump the tester until a pressure of 15,200 kPa (2200 psi) is attained on the pressure gauge. Close the pump isolator valve.

   Note: The pump isolator valve should be used to adjust the tester to the correct test pressure. Do not place excessive pressure on the nozzle assembly during this test.

3. Record the gauge reading after a 5 second time interval. Compare the test results to the specifications that are in Table 2.

4. Record the gauge reading after an additional 25 second time interval. Open the pump isolator valve in order to release the pressure on the fuel nozzle when the test is completed.

   The time interval for this portion of the test should be a total of 30 seconds. Compare the test results to the specifications that are in Table 2.

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   Table 2

   Specifications for Pressure Loss Direct Injection Fuel Systems
   Nozzle pressure must not drop below a gauge reading of 3450 kPa (500 psi) during a 5 second time interval.
   Nozzle pressure must drop below a gauge reading of 1380 kPa (200 psi) after an additional 25 second time interval. (1)

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   ( 1 )

   A gauge reading of 0 kPa (0 psi) is acceptable after the first 5 second time interval has elapsed.

Illustration 3	g00923167

If the fuel nozzle is not within specifications, stop the test and do not use the fuel nozzle.

Valve Opening Pressure Test

1. Slowly increase the pressure until fluid begins to flow from the tip of the fuel nozzle. Record this pressure as the VOP of the fuel nozzle.

2. Compare the test results to the specifications for the type of fuel nozzle that is being tested. Refer to Table 3, or Table 4.

For precombustion chamber fuel systems, use these specifications:

Illustration 4	g00934108

If the VOP is not within specifications, stop the test and do not use the fuel nozzle.

For direct injection fuel systems, use these specifications:

Illustration 5	g00923174

If the VOP is not within specifications, stop the test and do not use the fuel nozzle.

Tip Leakage Test (Direct Injection Fuel Systems)

Note: Fuel nozzles for precombustion chamber fuel systems can not be tested for tip leakage accurately. Do not perform this test on fuel nozzles for a precombustion chamber fuel system.

1. Close the gauge protector valve (0 to 40,000 kPa (0 to 5800 psi) gauge).

2. Flush the fuel nozzle that is being tested by pumping the tester for 3 full strokes.

3. Open the gauge protector valve (0 to 40,000 kPa (0 to 5800 psi) gauge).

4. Use a clean towel to wipe the tip of the fuel nozzle dry.

5. Slowly place a test pressure of 3450 to 6900 kPa (500 to 1000 psi) on the fuel nozzle.

6. Close the pump isolator valve.

7. Hold this test pressure for 30 seconds.

8. Open the pump isolator valve in order to release the pressure on the fuel nozzle when the test is completed.

   Compare the test results with the specifications that are in Table 5.

   Note: Ensure that any test fluid that collects on the tip of the fuel nozzle is not fluid leakage from the test fixture.

If the tip leakage for the fuel nozzle is not within specifications, stop the test and do not use the fuel nozzle.

Test the Fuel Nozzle for Plugged Orifices (Direct Injection Fuel Systems)

Note: Fuel nozzles for precombustion chamber fuel systems can not be tested for correct fuel atomization accurately. Do not perform this test on fuel nozzles for a precombustion chamber fuel system.

1. Close the gauge protector valve (0 to 40,000 kPa (0 to 5800 psi) gauge).

2. Rapidly increase the pressure on the fuel nozzle until fluid sprays from the tip of the fuel nozzle.

   Note: For this test, each full stroke of the pump should be performed in less than one second.

3. As the test fluid exits the tip of the fuel nozzle, observe the spray pattern of the fluid.

4. Compare the spray pattern to the spray pattern that is shown in Illustration 6.

Illustration 6	g00923173

If an orifice is plugged or the pattern is distorted, clean the fuel nozzle's orifice(s) and repeat this test. Refer to Special Instruction, SEHS8627, "Use of 8S-2245 Nozzle Cleaning Tool Group" for instructions on tool usage and cleaning procedures.

Damage to the fuel nozzle's orifice(s) can cause the engine to have a large change in horsepower. A spray pattern that is distorted can cause the engine to run rough. If an acceptable spray pattern can not be obtained, the fuel nozzle that is damaged must be replaced.