TM 5-3895-382-24
Cleaning Of Fuel Injector Nozzles
Before a fuel injector nozzle is tested, remove any loose
carbon from the tip of the fuel injector nozzle.
1.
Fasten the fuel injector nozzle in a holder or a vise with
brass jaws. Release the pressure on the nozzle holder
spring by loosening the adjusting screw. Remove the
nozzle cap nut and the nozzle with the correct size of
wrench.
Illustration 51
(8) Fuel inlet
(9) Cap nut
(10) Fuel return
(11) Pressure adjusting screw
(12) Spring for pressure adjusting screw
(13) Body
(14) Spindle for spring
(15) Retaining nut for fuel injector nozzle
(16) Valve needle
(17) Nozzle
(18) Seat washer
(19) Orifices
2.
Remove the valve needle (16) from the nozzle body.
Use the Brass Wire Brush in the 8S-2245 Cleaning Tool
Group in order to remove any carbon that may be on the
body (13).
3.
Clean the seat of the valve needle (16) and the fuel
reservoir with a Scraper. The Scraper is in the 8S-2245
Cleaning Tool Group.
NOTE: Use extra care not to break a wire of the brass
wire brush in an orifice (18) or passage in the fuel
injector nozzle. Removal of a broken wire is very
difficult. Removal of a broken wire may damage
the fuel injector nozzle.
4.
Clean the orifices (19) in the nozzle tip with a cleaning
wire. If the size is not known, carefully try different sizes
of wires in order to find the correct wire. Insert the wire
into the orifice. Slowly rotate the wire in order to clean
the orifice.
NOTE: Extra care must be used in handling the valve
needle (16) in order to prevent scratches or burrs
on the needle. Scratches and burrs could cause
leakage through the valve and spray distortion.
Pressure Test And Adjustment
Make sure 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.
Illustration 52
5P-4150 Nozzle Testing Group.
(1) 5P-7448 Adapter
(2) Fuel injector nozzle
(3) 6V-2170 Tube Assembly
(4) 1U-8857 Extension
(6) 8S-2270 Fuel Collector
(7) 8T-5313 Filter
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