Diagnosing Oil Leak on Ford's 7.3L Super Duty Truck Diesel Engine - Engine Builder Magazine

Diagnosing Oil Leak on Ford’s 7.3L Super Duty Truck Diesel Engine

Some 1998-2003 E-Series, 1999-2003 Super Duty, 2000-’03 Excursion and
2000-’03 F-650/750 vehicles equipped with a 7.3L diesel engine may
exhibit an oil leak at the high-pressure oil pump outlet fittings
and/or end plug.

According
to Ford, this type of leak may appear to be a rear main crankshaft
seal, oil pan gasket or other engine oil leak due to the drain hole
machined in the crankcase valley which allows any oil in the valley to
run down the back of the engine (see Figure 1).

High-pressure
oil pump leaks at the outlet fittings and/or end plug can be serviced
without removing the pump assembly. Replace the

O-rings on the
fillings and the end plug using kit 2C3Z-9G804-AA. All three O-rings
should be replaced. Apply liquid thread sealer (included in the kit)
prior to reinstallation.

Note: Do not remove the bottom plug — it is sealed in a different manner.
Figure 1

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