0211182 JOHNSON OWNERS MAN., Ev.

Top End Overhaul Information
A top end overhaul involves servicing the cylinder heads, pistons, rings, cylinder liners, and turbochargers. Also, 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 equipmentCat dealers are equipped with these tools. Cat 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 fuelThe following definitions explain the terminology for the services that are performed during an overhaul:Inspect - Inspect the components according to the instructions that are in Cat reusability publications. Refer to Guidelines for Reusable Parts and Salvage Operations, SEBF8029, "Index of Publications on Reusability or Salvage of Used Parts". The guidelines were developed to help Cat dealers and customers to avoid unnecessary expenditures. New parts are not required if the existing parts can still be used, reconditioned, or repaired. If the components are not in the reusability guidelines, refer to the Service Manual, "Specifications" module.Rebuild - The component can be reconditioned to comply with reusability guidelines.Replace - The service life of the part is exhausted. The part may fail before the next maintenance interval. The part must be replaced with a part that meets functional specifications. The replacement part may be a new part, a CAT remanufactured part, a rebuilt part, or a used part. Some worn components may be exchanged with your Cat dealer. Consult your Cat dealer about repair options for your engine.If you elect to perform an overhaul without the services of a Cat dealer, be aware of the recommendations in Table 1. Your Cat dealer can provide these services and components. Your Cat dealer can ensure that the components are operating within the appropriate specifications.
Table 1
Top End Overhaul
Clean Oil suction screen
Clean
Inspect
Test Aftercooler core
Oil cooler core
Inspect
Rebuild
Replace Bypass valve
Pistons
Transformers
Inspect
Replace Oxygen sensors
Rebuild Exhaust bypass
Prelube pump
Starting motor
Turbochargers
Water pumps
Replace Cylinder head assemblies
Cylinder liners
Insulation (heat shielding)
Oil temperature regulators
Piston rings
Solenoid (Cam Phasers)
Water temperature regulators Cleaning and Inspection of Components
Aftercooler and Oil Cooler
Clean the aftercooler core and the oil cooler core. Perform component pressure tests. Replace the components, if necessary.Note: If the cooling system is not properly maintained, cleaning of the aftercooler can be difficult. The tank that is opposite of the inlet port and the outlet port cannot be removed for cleaning.Note: This procedure may be used for cleaning both the aftercooler core and the oil cooler core.
Remove the core.
Turn the core upside-down 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 core and cause leakage. Only use the recommended concentration of cleaner.
Back flush the core with cleaner.Caterpillar recommends the use of Hydrosolv liquid cleaner. Consult your Cat dealer for part numbers and sizes of containers.Use a 2 to 5 percent concentration of the cleaner at temperatures up to 93°C (200°F).
Steam clean the core to remove any residue. Flush the fins of the core. Remove any other trapped debris.
Wash the core with hot, soapy water. Rinse the core thoroughly with clean water.
Personal injury can result from air pressure.Personal injury can result without following proper procedure. When using pressure air, wear a protective face shield and protective clothing.Maximum air pressure at the nozzle must be less than 205 kPa (30 psi) for cleaning purposes.
Dry the core with compressed air. Direct the air in the reverse direction of the normal flow.Note: The test pressure for the oil cooler is 790 kPa (115 psi). The maximum differential pressure of water for the aftercooler is 44 kPa (6 psi). The maximum differential pressure of air for the aftercooler is 5.1 kPa (0.74 psi).
Inspect the core to ensure cleanliness. Perform a pressure test on the core. Many shops that service radiators are equipped to perform pressure tests. If necessary, repair the core.
Install the core.For more information on cleaning the cores, consult your Cat dealer.Oil Suction Screen
Hot oil and components can cause personal injury.Do not allow hot oil or components to contact skin.
Clean the oil suction screen after the engine oil pan has been drained.Note: Approximately 1 L (1 qt) of engine oil will remain in the housing after the sump has been drained. This engine oil will pour out of the housing when cover (1) is removed. Prepare to catch the engine oil in a pan. Clean up any spills with absorbent towels or pillows. DO NOT use absorbent particles.