Introduction
This Special Instruction has been written in order to provide procedural information for testing pencil 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.
Note: The publications that are mentioned above may contain information that must be referenced in order to test the fuel injection nozzles.
Testing Pencil Type Fuel Nozzles
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. |
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NOTICE |
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Always ensure that the test fixture is in proper working order. Check that the fluid reservoir contains clean test fluid. Failure to do so may damage the fuel nozzles that you are testing and will reduce the life of the test equipment. |
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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:
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
Remove the Cap from the Fuel Nozzle
The cap must be removed from the fuel nozzle in order to prevent hydraulic lock during the testing procedure. Use the following steps in order to remove the fuel nozzle's cap.
Install the Fuel Nozzle onto the Tester
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Illustration 1 | g00935081 |
Note: 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.
Bleed the Air from the Nozzle Assembly
Test for Internal Return Leakage
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.
Refer to the information that is provided in Table 1 in order to evaluate the results of the test.
Specifications for Internal Return
Leakage (Leakage within 30 seconds after two drops of test fluid are allowed to drip from the tip of the nozzle.) | ||
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Nozzle Assembly | Minimum | Maximum |
1W-5829 | (1) | (1) |
4W-1819 | ||
4W-8483 | ||
7E-3969 | ||
7N-0449 | ||
7W-3710 | ||
7W-8043 | ||
9N-3979 | ||
101-0060 | ||
115-3354 | ||
122-9007 | ||
9L-7883 | 1 drop | 10 drops |
9L-9263 | ||
9N-2366 | ||
9L-6969 | 2 drops | 30 drops |
9N-3299 | ||
9N-3700 |
( 1 ) | No minimum or maximum specification |
If the fuel nozzle is not within specifications, stop the test and do not use the nozzle.
Valve Opening Pressure Test
Specifications for Valve Opening Pressure | |
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Nozzle Assembly | Valve Opening Pressure |
1W-5829 | 10300 to 17690 kPa (1500 to 2505 psi) |
4W-1819 | |
4W-8483 | |
7E-3969 | |
7N-0449 | |
7W-3710 | |
7W-8043 | |
9N-3979 | |
101-0060 | |
115-3354 | |
122-9007 | |
9L-7883 | 16560 to 17990 kPa (2400 to 2600 psi) |
9L-9263 | |
9N-2366 | |
9L-6969 | 13090 to 19900 kPa (1900 ± 2900 psi) |
9N-3299 | |
9N-3700 |
If the fuel nozzle is not within specifications, stop the test and do not use the nozzle.
Check for Tip Leakage
Use the fuel nozzle's valve opening pressure, that has been previously recorded, in order to calculate the test pressure for the nozzle that is being tested.
Refer to the information that is provided in Table 3 in order to evaluate the results of the test.
Note: Ensure that any test fluid that collects on the tip of the fuel nozzle is not fluid leakage from the test fixture.
Specifications for Tip Leakage
(Leakage within 15 seconds after the test pressure is applied to the nozzle.) | |
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Nozzle Assembly | Maximum Leakage |
1W-5829 | 20 drops (1) |
4W-1819 | |
4W-8483 | |
7E-3969 | |
7N-0449 | |
7W-3710 | |
7W-8043 | |
9N-3979 | |
101-0060 | |
115-3354 | |
122-9007 | |
9L-7883 | 3 drops (1) |
9L-9263 | |
9N-2366 | |
9L-6969 | 30 drops (1) |
9N-3299 | |
9N-3700 |
( 1 ) | No minimum specification |
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
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Illustration 2 | g00923165 |
Spray patterns for pencil type fuel nozzles. |
Note: For this test, each full stroke of the pump should be performed in less than one second.
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.
Reinstall the Cap onto the Fuel Nozzle
Note: Do not apply excessive torque when the cap is being installed. This could cause damage to the cap and to the fuel nozzle.
Cap Leakage Test
Note: 15 to 20 strokes may be required to reach the test pressure. A hydraulic lock can prevent the nozzle from opening when the cap is completely full of test fluid.
Test fluid should not leak from the cap of the nozzle. If leakage is present and the fuel nozzle cannot be repaired, do not use the nozzle.
For fuel nozzles that have completed the testing successfully, install a new compression seal and a new carbon dam seal prior to returning the fuel nozzle to service.