Basic Engine
FIG. 19 Typical Bearing Failures
Inspection
OIL PAN
After the block has been thoroughly cleaned, check it for
Cleaning
cracks. Minute cracks not visible to the naked eye may be
Scrape any dirt or metal particles from the inside of the
detected by coating the suspected area with a mixture of 25%
pan. Scrape all old gasket material from the gasket surface.
kerosene and 75%7 light engine oil. Wipe the part dry and
Wash the pan in a solvent and dry it thoroughly. Be sure all
immediately apply a coating of zinc oxide dissolved In wood
foreign particles are removed from below the baffle plate.
alcohol. If cracks are present, the coating will become
discolored at the defective area. Replace the block if it is
Inspection
cracked.
Check the pan for cracks. holes, damaged drain plug
Check all machined gasket surfaces for burrs, nicks.
threads, and a loose baffle or a damaged gasket surface.
scratches and scores. Remove minor imperfections with an oil
Inspect for damage (uneven surface) at the bolt holes caused
stone.
by over-torquing the bolts. Straighten surfaces as required.
Replace all expansion-type plugs that show evidence of
Repair any damage, or replace the pan if repairs cannot be
leakage.
made satisfactorily.
Inspect the cylinder walls for scoring, roughness, or other
signs of wear. Check the cylinder bore for out-of-round and
OIL PUMP
taper. Measure the bore with an accurate bore gauge
Cleaning
following the instructions of the manufacturer. Measure the
Wash all parts in a solvent and dry them thoroughly with
diameter of each cylinder bore at the top, middle and bottom
compressed air. Use a brush to clean the inside of the pump
with the gauge placed at right angles and parallel to the
housing and the pressure relief valve chamber. Be sure all dirt
centerline of the engine (Figure 20).
Use only the
and metal particles are removed.
measurements obtained at 90 degrees to the engine
centerline when calculating the piston to cylinder bore
Inspection
clearance.
Refer to the specifications for clearances and wear limits.
Refinish cylinders that are deeply scored and/or when out-
Check the inside of the pump housing and the outer race
of-round and/or taper exceed the wear limits. If the cylinder
and rotor for damage or excessive wear.
walls have minor surface imperfections, but the out-of-round
Check the mating surface of the pump cover for wear. If
and taper are within limits, it may be possible to remove such
the cover mating surface is worn, scored or grooved, replace
damage by honing the cylinder walls and installing new service
the cover.
piston rings providing the piston clearance is within specified
Measure the outer race to housing clearance (Figure 21).
limits.
Then check the clearance between the outer race and the
rotor lobes.
FIG 21. Checking Outer Race to Housing Clearance
FIG. 20 Cylinder Bore Out-of-Round and Taper
1-11
