0398768 JOHNSON CARBURETOR ASSY.

Replacement of Components
Replace the following components during the major overhaul.
Connecting rod bearings
Crankshaft seals
Crankshaft vibration damper
Electronic fuel injectors
Main bearings
Piston rings
Nonmetallic fuel lines (if equipped)
Clean emissions moduleInspection, Reconditioning, or Exchanging of Components
Inspect the following 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".Recondition the worn components or exchange the components, if necessary. Your Cat dealer can provide these services and components.
Camshaft followers
Connecting rods
Cylinder head assembly
Cylinder liners
Engine wiring harness
Exhaust bellows
Fuel transfer pump
Oil pump
Pistons
Piston pins
Prelube pump
Spacer plate
TurbochargersInspection of Components
Inspect the following 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".
Camshaft
Camshaft bearings
Crankshaft
Crankshaft thrust washers
Driven equipment (alignment)
Engine control module
Front gear train
Gear train bushings and bearings
Rear gear trainInspect the camshaft for damage to the journals and the lobes. Inspect the following components for signs of wear and/or for signs of fatigue:
camshaft bearings
camshaft followersInspect the crankshaft for any of the following conditions:
deflection
damage to the journals
bearing material that has seized to the journalsCheck the journal taper and the profile of the crankshaft journals. Check these components by interpreting the wear patterns on the following components:
rod bearing
main bearingsNote: If the crankshaft or the camshaft are removed for any reason, use the magnetic particle inspection process to check for cracks.Replace the crankshaft vibration damper if any of the following conditions occur:
Engine failure due to a broken crankshaft
Excessive wear of the front bearing for the crankshaft
Excessive wear of the gear train that is not caused by a lack of lubricationInspect the gears of the gear train and inspect the gear train bushings for the following conditions:
Worn gear teeth
Unusual fit
Unusual wearIn addition to the inspection of components, inspect the alignment of the driven equipment. See the Application and Installation Guide for the engine or see the literature that is provided by the OEM of the driven equipment.Cleaning of Components
Clean the oil cooler core and the aftercooler core. Then, pressure test both of these cores. For instructions on cleaning the cores, see this Operation and Maintenance Manual, "Aftercooler Core - Clean/Test" topic.Clean the oil suction screen. Also, remove side covers in order to clean the oil sump. For instructions on removal and installation of components, see the Service Manual, "Disassembly and Assembly" module.Obtain a Coolant Analysis
For conventional heavy-duty coolant or antifreeze, check the concentration of supplemental coolant additive (SCA) regularly. The concentration of SCA can be checked with an S O S coolant analysis (Level One). A more detailed coolant analysis is recommended periodically.For example, considerable deposits are found in the water jacket areas on the external cooling system, but the concentrations of coolant additives were carefully maintained. The coolant probably contained minerals which were deposited on the engine over time.A coolant analysis can be conducted in order to verify the condition of the water that is being used in the cooling system. A full water analysis may be obtained from the following sources:
Cat dealer
Local water utility company
Agricultural agent
Independent laboratoryCaterpillar recommends an S O S coolant analysis (Level Two). This analysis is a comprehensive chemical evaluation of the coolant. This analysis is also a check of the overall condition of the inside of the cooling system. The following services are provided:
Full Level One analysis
Identification of the source of metal corrosion and of contaminants
Identification of buildup of the impurities that cause corrosion
Identification of buildup of the impurities that cause scaling
Determination of possible electrolysis within the engines cooling systemA report of the results of the analysis is provided. Maintenance recommendations are based on the results.For more information about S O S coolant analysis, consult your Cat dealer.