This week's project was to remove the
fuel injectors off of our FLD Freightliner. These injectors are N2
single-actuated EUIs (electronic unit injectors), which are bulkier than the newer N3 injectors.
In order to get the
valve cover off, removal of the air filter housing and the radiator
inlet hose off of the top of the valve cover was necessary.
Afterwards we removed the valve cover, jake brake assemblies, rocker
arm assemblys, and finally the injectors themselves. We removed the front 3 injectors from cylinders 1-3 (which I unfortunately did not remember to take pictures of)
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| Jake brake and rocker arm assemblies. |
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| Valves and injector on cylinder #1. |
Some thoughts on what I learned this
week:
Care must be taken when removing the
injectors as it is possible to spill fuel in the injector bore onto
the piston. This can cause hydrostatic lock (too much
non-compressible liquid in the cylinder which has no way to escape as
the piston moves to top dead center on the compression stroke) and cause serious damage to
vital engine components such as bending the connecting rod.
To prevent this, service literature recommends draining all the fuel from the cylinder head by removing both inlet and outlet lines at their fittings at the rear of the cylinder head and blowing low-pressure compressed air through the inlet fitting until all fuel has been purged from the cylinder head.
-Erik Miehrig
Excellent post, Erik! The attention to "hydrostatic lock" applies to the piston as well as the bolt holes for the rocker assemblies. I just looked at the service manual and they advocate draining fuel from the lines at the back of the head. That is the procedure that you have to lay on top of the engine, with your face just inches away from the firewall, to remove the fuel.
ReplyDeleteExcellent use of the English language. Keep up the good work!