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Back High-Pressure Test | Up Construction Mechanic Advanced - Construction methods and practices | Next Cummins Pressure Time Fuel Injection System |
in the comparator (fig. 5-32), and seal the injector firmly
by tightening the handwheel. Pull the injector rack out
to the NO-FUEL position and start the comparator.
After the comparator has started, push the injector rack
to the FULL-FUEL position. Let the injector run for
approximate y 30 seconds to purge air in the system.
After 30 seconds, press the fuel flow start button to start
the flow of fuel into the vial. The comparator will
automatically stop the flow of fuel after a thousand
strokes. After the fuel has stopped flowing into the vial,
pull the injector rack out to the NO-FUEL position.
Turn the comparator off, reset the counter, and observe
the reading on the vial. Refer to the chart on the
comparator and see if the injector fuel output falls within
its specified limits. If the quantity of fuel in the vial does
not fall within the specified limits, refer to the
manufacturers manual for the cause and remedy. Any
injector that has been disassembled and rebuilt must be
tested again before being placed in service.
Injector Disassembly, Cleaning and Inspecting,
and Reassembly
To disassemble an injector, you should place it in an
injector assembly fixture. Now, you are ready to remove
the falter caps, springs, filter elements, and gaskets.
Discard the falter elements and gaskets and replace them
with new components during reassembly. Follow the
manufacturers repair and maintenance manual when
disassembling injectors.
While you disassemble an injector, put the injector
and its parts together in a separate receptacle containing
a cleaning solvent or clean diesel fuel oil.
Wash all the parts and dry them. Do not use rags for
cleaning. Clean out all passages, drilled holes, and slots
in all of the injector parts.
You should soak injector spray tips in a suitable
solvent for approximately 15 minutes. This loosens the
Figure 5-32.-Comparator used to check injector fuel output.
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