5_108.bk Page 199 Thursday, October 4, 2001 11:45 AM
REPAIR INSTRUCTIONS 5. Remove injection pump from holding fixture.
The recess in the drive hub is now in position to clear the camshaft gear during installation. 266
Injector Nozzle Inspection and Cleaning Injector nozzles (with six spray holes) are a Valve Covering Orifice (VCO) configuration and are hydroground for proper fuel flow and atomization. When servicing nozzle holder assemblies, cleaning of nozzle tips may be necessary. Special care must be taken when cleaning nozzle tips to avoid damaging nozzle spray holes. r
Preferred cleaning method: ultrasonic cleaning
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Acceptable cleaning method: brass brush/ wire wheel
ULTRASONIC CLEANING METHOD Ultrasonic cleaning is the preferred method for cleaning the fuel injector nozzles. Ultrasonic cleaning units, such as J 29653-A, use sound waves or mechanical vibrations approximately 55,000 cycles per second above human hearing range. The sound waves are generated by the transducer, which changes high-frequency electrical energy into mechanical energy. Figure 266 — Removing Injection Pump from Fixture
Do not rotate pump during or after removal from fixture. Hub would not be properly aligned for installation into engine.
BRASS BRUSH/WIRE WHEEL METHOD Cleaning the fuel injector nozzles with a brass brush or wire wheel may be acceptable under some conditions, but it is not recommended. The nozzles will be damaged if a steel wire wheel is used for cleaning. Damage can also occur if an improper size brass-wire wheel and/or improper speed is used.
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