Various factors such as the type of operation of the
In many cases, a serviceman is justified in replacing
engine, hours in service and next overhaul period must
parts with new material rather than attempting repair.
be considered when determining whether new parts are
However, there are times where a slight amount of
installed or used parts are reconditioned to provide
reworking or reconditioning may save a customer
considerable added expense. Crankshafts, cylinder
liners and other parts are in this category. For example,
For convenience and logical order in disassembly and
if a cylinder liner is only slightly worn and within usable
assembly, the various sub-assemblies and other related
limits, a honing operation to remove the glaze may
parts mounted on the cylinder block will be treated as
make it suitable for reuse, thereby saving the expense
separate items in the various sections of the manual.
of a new part. Exchange assemblies such as injectors,
fuel pumps, water pumps and blowers are also desirable
only a few items need replacement, it is not always
Before any major disassembly, the engine must be
necessary to mount the engine on an overhaul stand.
drained of lubricating oil, water and fuel.
Parts removed from an individual engine should be kept
together so they will be available for inspection and
To perform a major overhaul or other extensive repairs,
assembly. Those items having machined faces, which
the complete engine assembly, after removal from the
might be easily damaged by steel or concrete, should be
engine base and drive mechanism, should be mounted
stored on suitable wooden racks or blocks, or a parts
on an engine overhaul stand; then the various sub-
assemblies should be removed from the engine. When
Solvent Tank Cleaning
Before removing any of the sub-assemblies from the
engine (but after removal of the electrical equipment),
A tank of sufficient size to accommodate the largest part
the exterior of the engine should be thoroughly cleaned.
that will require cleaning (usually the cylinder block)
Then, after each sub-assembly is removed and
should be provided and provisions made for heating the
disassembled, the individual parts should be cleaned.
cleaning solution to 180-200 °F (82-90 °C).
Thorough cleaning of each part is absolutely necessary
before it can be satisfactorily inspected. Various items
Fill the tank with a commercial heavy-duty solvent which
of equipment needed for general cleaning are listed
is heated to the above temperature. Lower large parts
directly into the tank with a hoist. Place small parts in a
wire mesh basket and lower them into the tank.
The cleaning procedure used for all ordinary cast iron
Immerse the parts long enough to loosen all of the
parts is outlined under Clean Cylinder Block in Chapter
grease and dirt.
2; any special cleaning procedures will be mentioned in
the text wherever required.
Provide another tank of similar size containing hot water
for rinsing the parts.
A steam cleaner is a necessary item in a large shop and
Parts may be dried with compressed air. The heat from
is most useful for removing heavy accumulations of
the hot tanks will quite frequently complete the drying of
grease and dirt from the exterior of the engine and its
the parts without the use of compressed air.