INSERT (EXHAUST) 9M6495 - Caterpillar

Scheduling a Top End Overhaul
Top end overhauls are scheduled according to the recession of the exhaust valve stems. This measurement provides an accurate indication of the rate of valve wear. This measurement can be used to predict when a cylinder head requires replacement. For more information, see this Operation and Maintenance Manual, "Valve Stem Projection - Measure/Record" topic.Note: The generator or the driven equipment may also require service when the engine overhaul is performed.Top End Overhaul Information
A top end overhaul involves servicing the cylinder heads and turbochargers. Also, some other engine components are inspected.Top end overhauls require more tools than preventive maintenance. The following tools are needed for restoring the engine to factory specifications:
Torque wrenches
Dial indicators
Accurate measurement tools
Cleaning equipment
Rebuilding equipmentCaterpillar dealers are equipped with these tools. Caterpillar dealers can provide a flat rate price for a top end overhaul.Unexpected problems may be found during a top end overhaul. Plan to correct these problems, if necessary.
Build up in the cylinders from excessive oil consumption
Build up in the cylinders from contamination of the fuel
Plugging of the aftercooler from coolant that is poorly maintained
Plugging of the aftercooler from contamination of the inlet air
Degradation of the oil cooler from hydrogen sulfide in the fuelInspect the following components according to the instructions that are in Caterpillar reusability publications. Refer to Guidelines for Reusable Parts and Salvage Operations, SEBF8029, "Index of Publications on Reusability or Salvage of Used Parts".Your Caterpillar dealer can provide these services and components. Your Caterpillar dealer can ensure that the components are operating within the appropriate specifications.If you elect to perform an overhaul without the services of a Caterpillar dealer, be aware of the following recommendations.Replacing of Components
Note: The cylinder head may be rebuilt, when possible.Replace the following components during a top end overhaul.
Alternator and fan drive belts
Cylinder heads and gaskets
Hoses and clamps
Rod ends for the control linkage of the actuator
Spark plugs
Spark plug wires
Water temperature regulatorRebuilding of Components
Rebuild the following components during a top end overhaul:
Carburetor
Gas regulator
Magneto
Starting motor
Turbocharger
Water pumpsNote: Periodic inspection of the turbocharger is recommended for determining when the turbocharger will require an overhaul. In a few applications, the turbocharger may require rebuilding prior to the top end overhaul. An example is an application with loads that vary frequently. In these cases, rebuilding the turbocharger normally occurs separately from rebuilding the cylinder heads. Some applications can operate longer before the turbocharger requires rebuilding. Only experience can determine the actual need.Inspecting of Components
Clean the following components. Pressure test the components. Replace the components, if necessary:
Aftercooler core (if equipped)
Oil cooler coreNote: If proper maintenance of the cooling system is not performed, the aftercooler core can be difficult to clean.Note: This procedure may be used for cleaning both the aftercooler core and the oil cooler core.
Remove the core. For the procedure, see the Service Manual, "Disassembly and Assembly" module.
Turn the core upside-down in order to remove debris.
Do not use a high concentration of caustic cleaner to clean the core. A high concentration of caustic cleaner can attack the internal metals of the