D353 INDUSTRIAL & MARINE ENGINES Caterpillar


Systems Operation

Usage:



Fuel System


SCHEMATIC OF THE FUEL SYSTEM
1. Fuel priming pump. 2. Fuel transfer pump. 3. Fuel injection pump. 4. Precombustion chamber. 5. Fuel supply line. 6. Primary fuel filter. 7. Bypass valve for fuel transfer pump. 8. Air vent valve. 9. Fuel filters. 10. Fuel manifold.

This engine has a pressure type fuel system. There is a single injection pump and injection valve for each cylinder. The injection pumps (3) are in the pump housing on the right side of the engine. The injection valves are in the precombustion chambers (4) in the top left side of the cylinder head.

The transfer pump (2) sends fuel from the fuel tank to the primary fuel filter (6). The primary fuel filter (6) removes the larger dirt particles from the fuel. Fuel goes from the primary fuel filter (6) to the fuel filters (9). The fuel filters (9) remove the smaller dirt particles from the fuel. Fuel goes from the fuel filters (9) to the fuel manifold (10) in the pump housing. This manifold is the source of fuel supply for each injection pump (3). The injection pumps (3) send fuel through high pressure fuel lines to the injection valves. The injection valves change the fuel to the correct fuel characteristic (spray pattern) for good combustion in the cylinders.

The transfer pump (2) can supply more fuel than is necessary for injection, so a bypass valve (7) is used to control the pressure of the fuel in the fuel system.

An air vent valve (8) in the fuel system is used to remove air from the fuel system. Air is removed by opening the air vent valve and putting pressure to the fuel system with the priming pump (1). Put pressure to the fuel system until a flow of fuel, free of air bubbles, comes from the vent line.

Fuel Injection Pump Operation

Injection pump plungers (3) and lifters (6) are lifted by cams on camshaft (7) and always make a full stroke. The force of springs (5) hold the lifters (6) against the cams of the camshaft.

Fuel from fuel manifold (1) goes through inlet passage (2) in the barrel and then into the chamber above plunger (3). During injection, the camshaft cam moves plunger (3) up in the barrel. This movement will close inlet passage (2) and push the fuel out through the fuel lines to the injection valves.

The amount of fuel sent to the injection valves is controlled by turning plunger (3) in the barrel.


CROSS SECTION OF THE HOUSING FOR THE FUEL INJECTION PUMPS
1. Fuel manifold. 2. Inlet passage in pump barrel. 3. Pump plunger. 4. Gear segment. 5. Spring. 6. Lifter. 7. Camshaft.

When the governor moves the fuel rack, the fuel rack moves gear segment (4) that is fastened to the bottom of plunger (3).

Mechanical Governor


MECHANICAL GOVERNOR-LEFT SIDE VIEW (Typical Example)
1. High idle adjustment screw. 2. Low idle adjustment screw. 3. Stop. 4. Roller. 5. Spring. 6. Plunger. 7. Adjustment screw. 8. Lower housing. 9. Oil passage. 10. Weight. 11. Governor drive spindle.

The governor control, is connected to the control lever on the engine governor. The governor controls the amount of fuel needed to keep the engine at the desired rpm.

The governor has weights (10), which are driven by the engine. The force of the weights (10) on sleeve (14), bearing (13) and cage (12), puts force against force of spring (5). These two forces move the fuel rack through lever (15) to control the engine rpm.

The governor control, controls only the compression of governor spring (5). Compression of the spring always pushes to give more fuel to the engine. The centrifugal force (rotation) of weights (10) is always pulling to get a reduction of fuel to the engine. When these two forces are in balance, the engine runs at the desired rpm (governed rpm).


MECHANICAL GOVERNOR (FRONT VIEW)
5. Spring. 7. Adjustment screw. 8. Lower housing. 10. Weight. 11. Governor drive spindle. 12. Cage. 13. Bearing. 14. Sleeve assembly. 15. Lever.

When the load on the engine goes up, there is a reduction in engine rpm and the rotation of governor weights (10) will get slower. (The governor weights will move toward each other). Governor spring (5) moves the rack by way of bearing (13), cage (12) and lever (15) to give the engine more fuel.

Engine rpm goes up until rotation of the governor weights is fast enough to be in balance with the force of the governor spring.

When there is a reduction in engine load, there will be an increase in engine rpm and the rotation of governor weights (10) will get faster. This will move lever (15) and it pushes the fuel rack, by way of bearing (13), cage (12) and lever (15). There is now a reduction in the amount of fuel to the engine. Engine rpm goes down until the centrifugal force (rotation) of the governor weights is in balance with the force of the governor spring. When these two forces are in balance, the engine will run at the desired rpm (governed rpm).

When engine rpm is at LOW IDLE, a spring-loaded plunger (6) comes in contact with the bottom of roller (4) on the adjustment screw for low idle. To stop the engine, pull back on the governor control. This will let the spring-loaded plunger move over the roller on the low idle adjusting screw.

Oil from the engine enters the governor through passage (9) and gives lubrication to the governor flexible spindle (11) and upper parts of the governor. The upper parts of the governor get lubrication from "splash-lubrication" (oil thrown by other parts). Oil from the governor runs back into the timing gear housing through an oil return hole at the rear of the drive housing for the governor.

Hydra-Mechanical Governor

An oil pump gear (10), part of shaft assembly (11), provides immediate pressure oil for the servo portion of the governor. A sump in body assembly (12) provides immediate supply for the pump. A bypass valve (B), in the body assembly, maintains correct pressure for servo supply oil.

When the engine is operating, pressure oil from the pump is directed through passage (6) in cylinder (5), to a space around sleeve (7) and through an oil passage in piston (9) to a groove around valve (8). When revolving weights (2) slow down (occurring when engine load increases), the weights move in allowing governor spring (1) to move valve (8) downward. When the valve moves downward, the oil passage in piston (9) opens to the pressure oil in the groove around valve (8) and pressure oil is now at the large area end of piston (9) and pushes the piston, valve (8) and shaft (15) downward. Shaft (15) pushes lever (13), moving fuel rack (14) forward thus increasing the amount of fuel to the engine.

With more fuel, engine rpm increases until the revolving weights (2) again rotate fast enough to balance the force of the governor spring. The passage in piston (9) will be between the oil pressure groove and the oil drain groove in valve (8). The movement of piston (9), valve (8), shaft (15), lever (13) and fuel rack (14) stops and the engine rpm is the same as before. When engine load decreases, revolving weights (2) speed up and toes on the weights move valve (8) upward opening oil passage in piston (9) to the drain groove around valve (8). Oil pressure between sleeve (7) and piston (9) pushes the piston, valve (8) and shaft (15) upward which moves fuel rack (14) to decrease the amount of fuel to the engine and the rpm of the engine (and revolving weights) decreases. When revolving weight force again balances governor spring force, the rpm of the engine is the same as before.


GOVERNOR CROSS SECTION
1. Governor spring. 2. Flyweights. 3. Thrust bearing. 4. Seat. 5. Cylinder. 6. Oil passage. 7. Sleeve. 8. Valve. 9. Piston and valve assembly. 10. Gear. 11. Shaft assembly. 12. Body assembly. 13. Lever. 14. Fuel rack. 15. Shaft. A. Speed limiter (engines so equipped). B. Bypass valve.

The engine is stopped by pushing the governor control past detent.

An oil passage through the center of valve (8) has a small oil outlet near the top end of the valve to lubricate thrust bearing (3) under seat (4). The bearing surface of revolving weight assembly (2) drive gear receives lubricating oil from the oil around sleeve (7) through an opening in cylinder (5).

Governor action will change if there is a loss in lubricating oil pressure; however, the governor still offers protection against engine overspeeding because the weight assembly is mechanically connected to the fuel rack. The mechanical connections make it possible to move the fuel rack to the SHUTOFF position by using the controls normally used to stop the engine.

When the engine is started, speed limiter plunger (A) restricts the movement of the governor control linkage. When operating oil pressure is reached, the plunger in the speed limiter retracts and the governor control can be moved to the HIGH IDLE position.

Fuel Ratio Control (Hydraulic Activated)

The hydraulic activated fuel ratio control automatically causes a restriction to the amount of travel of the rack in the "fuel on" direction, until the air pressure in the inlet manifold is high enough to give complete combustion. The fuel ratio control keeps engine performance high so that black exhaust gases are not seen.


FUEL RATIO CONTROL (HYDRAULIC ACTIVATED)
1. Valve. 2. Oil inlet passage. 3. Passage for inlet air pressure. 4. Oil outlet passage. 5. Large oil passage. 6. Oil drain. 7. Spring. 8. Diaphragm. 9. Valve.

The hydraulic activated fuel ratio control has two valves (1) and (9). Engine oil pressure works against valve (1) to control the movement of the fuel rack. Air pressure from the inlet manifold works against diaphragm (8) to move valve (9) to control oil pressure against valve (1).

When the engine is stopped, there is no pressure no either valve. Spring (7) moves both valves to the ends of their travel. In this position, the fuel rack travel is not restricted. Also in this position, an oil outlet passage (4) is open to let oil away from valve (1).

When the engine is started, the open oil outlet passage (4) prevents oil pressure against valve (1) until air pressure from the inlet manifold is high enough to move valve (9) to close the large oil passage (5). Engine oil pressure then works against valve (1) to move this valve into its operating position. The control will operate until the engine is stopped.

When the governor control is moved toward the full load position with the engine running, the head on the stem of valve (1) will cause a restriction to the travel of the fuel rack, until the air pressure in the inlet manifold has an increase. As there is an increase in the air pressure in the inlet manifold, this pressure works against diaphragm (8) to cause valve (9) to move to the left. The large oil passage (5) becomes open to let oil pressure away from valve (1), toward spring (7), and out to drain (6). As there is a decrease in oil pressure, valve (1) moves to the left to let the fuel rack open at a rate equal to (the same as) the air available for combustion.

Fuel Injection Valve

Fuel, under high pressure from the injection pumps, is sent through the injection lines to the injection valves. When fuel under high pressure goes into the nozzle assembly, the check valve inside the nozzle opens. This permits the fuel to get into the precombustion chamber with the correct characteristics (spray pattern).


FUEL INJECTION VALVE AND PRECOMBUSTION CHAMBER CROSS SECTION
1. Fuel injection line. 2. Nut. 3. Glow plug. 4. Body. 5. Nozzle assembly.

Timing Gears

The timing gears are in a compartment at the rear of the cylinder block. Their cover is the front face of the flywheel housing. The timing gears keep the rotation of the crankshaft, camshaft, fuel pump and governor drive in the correct relation to each other. The timing gears are driven by a gear in front of the rear flange of the crankshaft.

The crankshaft gear (10) turns the gear (5) for the accessory drive. This gear turns the idler gear (2) for camshaft and governor drive. The crankshaft gear (10) also turns the idler gear (8). The idler gear (8) turns the water pump gear (4) and charging unit or auxiliary drive gear (6).


TIMING GEARS
1. Governor drive. 2. Idle gear for camshaft and governor drive. 3. Camshaft gear. 4. Water pump gear. 5. Gear for accessory drive. 6. Charging unit or auxiliary drive gear. 7. Spur gear. 8. Idler gear. 9. Gear to drive oil pump. 10. Crankshaft gear.

Air Inlet And Exhaust System


AIR INLET AND EXHAUST SYSTEM
1. Exhaust manifold. 2. Inlet manifold. 3. Aftercooler. 4. Engine cylinder. 5. Turbocharger impeller. 6. Turbocharger turbine wheel. 7. Air inlet. 8. Exhaust outlet.

The air inlet and exhaust system components are: air cleaner, inlet manifold, cylinder head, valves and valve system components, exhaust manifold, turbocharger, and muffler.

The air cleaner cleans the air before it gets into the turbocharger and inlet manifold. The turbocharger gives air boost to the inlet air for the engine. Changes in load on the engine and the injection of fuel will cause a change in rpm of the turbocharger turbine wheel and impeller. When the load on the engine goes up the rpm of the turbocharger will increase to give more air to the engine.

When the turbocharger gives a pressure boost to the inlet air, the temperature of the air goes up. A water-cooled aftercooler (3) is installed between the turbocharger and the air inlet manifold to cylinders. The aftercooler will cool the hot air from the turbocharger.

Aftercooler

Water flow through the aftercooler, lowers the temperature at the inlet air from the turbocharger. With cooler air, an increase in weight of air will permit more fuel to burn. This gives an increase in power. The aftercooler can be changed to use sea water as the coolant. Sea water must not be used in fresh water cores.

Turbocharger

The turbocharger is installed at the rear of the exhaust manifold. All the exhaust gases from the diesel engine go through the turbocharger.

The exhaust gases go through the blades of the turbine wheel. This causes the turbine wheel and compressor wheel to turn.

Clean inlet air from the air cleaner is pulled through the air inlet of the compressor housing by the compressor wheel. The compressor wheel causes a compression of the air. The air goes to the aftercooler and then to the inlet manifold of the engine.

When the load on the engine goes up, more fuel is put into the engine. This makes more exhaust gases and will cause the turbine and compressor wheels of the turbocharger to turn faster. As the turbocharger turns faster it gives more inlet air and makes it possible for the engine to burn more fuel and will give the engine more power.

Maximum rpm of the turbocharger is controlled by the rack setting, the high idle speed setting and the height above sea level at which the engine is operated.

------ WARNING! ------

If the high idle rpm or the rack setting is higher than given in the RACK SETTING INFORMATION (for the height above sea level at which the engine is operated), there can be damage to engine or turbocharger parts.

--------WARNING!------


CROSS SECTION OF TURBOCHARGER
1. Compressor wheel. 2. Compressor housing. 3. Lubrication inlet port. 4. Turbine housing. 5. Thrust bearing. 6. Turbine wheel. 7. Air inlet. 8. Exhaust outlet. 9. Sleeve. 10. Shaft journal bearings. 11. Seals. 12. Exhaust inlet.

The turbocharger bearings use engine oil under pressure for lubrication. The oil comes in through port (3) and goes through passages for lubrication of the thrust bearing (5), rings and the bearings (10). Oil from the turbocharger goes through an opening in the bottom of the center section and to the engine sump.

The adjustment of the fuel rack is done at the factory for a specific engine application. The governor housing and turbocharger are sealed to prevent not needed changes in the adjustment of the rack and the high idle speed.

Valves And Valve Mechanism (Earlier)


VALVE AND VALVE MECHANISM
1. Rocker arm. 2. Locks. 3. Retainer. 4. Push rod. 5. Spring. 6. Valve rotator. 7. Guide. 8. Valve lifter. 9. Valve.

The valves and valve mechanism control the flow of air and exhaust gases in the cylinder during engine operation.

The intake and exhaust valves are opened and closed by movement of these components: crankshaft, camshaft, valve lifters (cam followers), push rods, rocker arms, and valve springs. Rotation of the crankshaft causes rotation of the camshaft. The camshaft gear is driven by, and timed to, a gear on the crankshaft. When the camshaft turns, the cams on the camshaft also turn and cause the valve lifters (cam followers) to go up and down. This movement makes the push rods move the rocker arms. The movement of the rocker arms will make the intake and exhaust valves in the cylinder head open and close according to the firing order (injection sequence) of the engine. A valve spring for each valve helps to hold the valves in the closed position.

Valve rotators cause the valves to have rotation while the engine is running. This rotation of the valves keeps the deposit of carbon on the valves to a minimum and gives the valves longer service life.

Valves And Valve Mechanism (Later)


VALVE AND VALVE MECHANISM
1. Rocker arm. 2. Locks. 3. Retainer. 4. Push rod. 5. Springs. 6. Valve rotator. 7. Guide. 8. Valve lifter. 9. Valve.

The valves and valve mechanism control the flow of air and exhaust gases in the cylinder during engine operation.

The intake and exhaust valves are opened and closed by movement of these components: crankshaft, camshaft, valve lifters (cam followers), push rods, rocker arms, and valve springs. Rotation of the crankshaft causes rotation of the camshaft. The camshaft gear is driven by, and timed to, a gear on the crankshaft. When the camshaft turns, the cams on the camshaft also turn and cause the valve lifters (cam followers) to go up and down. This movement makes the push rods move the rocker arms. The movement of the rocker arms will make the intake and exhaust valves in the cylinder head open and close according to the firing order (injection sequence) of the engine. Two valve springs for each valve help to hold the valves in the closed position.

Valve rotators cause the valves to have rotation while the engine is running. This rotation of the valves keeps the deposit of carbon on the valves to a minimum and gives the valves longer service life.

Lubrication System


SCHEMATIC FLOW DIAGRAM OF THE LUBRICATION SYSTEM
1. Oil pressure gauge. 2. Oil line to fuel injection pump. 3. Oil passage in rocker arm shaft. 4. Oil passage in governor lower housing. 5. Supply tube from camshaft oil manifold to rocker arm shaft. 6. Camshaft oil manifold. 7. Oil filter. 8. Oil cooler. 9. Turbocharger oil drain tube. 10. Turbocharger oil supply tube. 11. Oil manifold. 12. Oil pump outlet line. 13. Unfiltered oil line to turbocharger lubrication valve. 14. Turbocharger lubrication valve. 15. Scavenge oil line. 16. Piston cooling spray tubes. 17. Filtered oil line to turbocharger lubrication valve. 18. Oil pump (two section). 19. Suction bell. 20. Oil sump.

Main Lubrication System

Oil from the oil sump (20) goes through oil cooler (8), filter (7) and into manifold (11) for distribution.

A regulating valve in the oil pump controls the maximum pressure of the oil from the pump (18). A valve in the filter housing lets oil go around the oil filter elements when cold oil causes a reduction to flow. When the oil is warm, only clean (filtered) oil goes to the engine bearings. Restriction in the oil filter elements causes the filter valve to open. This sends the flow to the oil distribution manifold.

The manifold for oil distribution sends oil through connecting passages and lines to the inside and outside components of the engine.

Lubrication of Outside Component

The turbocharger, governor, fuel injection pump housing and the drive for the governor and fuel pump get oil from the oil manifold (11).

A turbocharger lubrication valve (14) is on the right side of the engine under the oil filter. When the engine is started, there is a restriction, for a moment, of the oil flow through the cooler (8) and filter (7). The lubrication valve opens and oil flow is to the turbocharger. When pressure restriction through the cooler and filter is removed, the turbocharger lubrication valve closes to send filtered oil to the turbocharger.

Lubrication of Inside Components

The manifold (11) sends oil through passages and tubes to: oil spray tubes (16) for pistons, crankshaft bearings, connecting rod bearings and to oil manifold (6) for the camshaft.

The oil manifold (6) for the camshaft sends oil to the shaft (3) for the valve rocker arm and camshaft bearings.

Timing Gears

Oil under pressure goes to the thrust bearing for the camshaft. The gears get lubrication oil from the oil manifold (6). The points of lubrication are shown in the lubrication diagram of the timing gears.


LUBRICATION DIAGRAM OF THE TIMING GEARS
1. Passage. 2. Tube. 3. Passage. 4. Bearing for the idler gear for the camshaft. 5. Passage. 6. Manifold. 7. Rear bearing for the camshaft. 8. Groove. 9. Tube. 10. Gauge for oil pressure. 11. Rear bearing for the camshaft, fuel pump and governor drive shaft. 12. Water pump bearing. 13. Opening. 14. Junction block. 15. Drilled passage. 16. Charging unit rear bearing. 17. Idler gear bearing. 18. Idler gear bearing. 19. Rear main bearing. 20. Bearing for the drive gear for the oil pump.

Lubrication for most of the points are from pressure oil in the system. The points not supplied with pressure oil are: bearing (12) for the water pump, bearing (20) for the oil pump drive shaft and the gear driven charging unit rear bearing (16). Lubrication of the bearing (12) for the water pump and bearing (20) for the drive of the oil pump is with oil thrown from other parts.

The bearing (16) for the rear of the gear driven changing unit is filled with grease and must be disassembled for refilling.

The opening (13) permits oil passage back to the crankcase from the drive housing for the fuel pump and governor drive.

Cooling System

The water pump (8) is installed on the right side of the engine on the front face of the timing gear housing. The water pump is gear driven. An extension of the water pump shaft through the timing gear housing makes an auxiliary drive.

Water pump inlet pipe (11) is fastened to the radiator or expansion tank outlet. Coolant from the pump (8) goes through the piping to oil cooler (10).

On engines equipped with attachments that have heat exchanger type oil cooler for a marine gear, which should use fresh water, there is a connection of the small heat exchanger between the engine oil cooler (10) and the cylinder block (9).

The coolant then goes around the cylinder block (9) around the cylinder liners and upward through the cylinder heads (3). Where the water cooled exhaust manifold is used, coolant goes from the cylinder heads to the water cooled exhaust manifolds.

The coolant goes forward to the housing for the temperature regulators at the front of the engine.

Water temperature regulators, positioned in the housing, control coolant flow to the radiator (5), keel cooling coils (14) or heat exchanger (13) to control the temperature in the cooling system.

There is a bypass line (7) from the inlet side of the temperature regulator housing to the inlet side of the water pump at (8). When the temperature of the coolant is not high enough to open the regulators, coolant bypasses the radiator, keel cooling coils or heat exchanger to circulate through engine, for quick warm-ups. None of the coolant goes through the bypass lines when the engine is working full load.


FLOW OF COOLANT IN KEEL COOLING SYSTEM
1. Aftercooler. 2. Water cooled exhaust manifold. 3. Cylinder head. 4. Temperature regulator housing. 6. Expansion tank. 7. Bypass line. 8. Water pump. 9. Cylinder block. 10. Oil cooler. 11. Inlet pipe. 12. Marine gear oil cooler. 14. Keel cooling coils.

Basic Block

Vibration Damper

The twisting of the crankshaft, due to the regular power impacts along its length, is called twisting (torsional) vibration. The vibration damper is installed on the front end of the crankshaft. It is used for reduction of torsional vibrations and stops the vibration from building up to amounts that could cause damage.

The damper is made of a steel ring (1) bonded to disc (3) by rubber core (2). Disc (3) is fastened with bolts to the crankshaft flange (4). The force of rotation from the crankshaft is sent (transfered) to the ring (1). The power impacts sent thru the rubber core (2) are reduced with delay, to the ring. This acts as a pull against the power impacts to cause a reduction of vibrations of the crankshaft.


CROSS SECTION OF VIBRATION DAMPER
1. Ring. 2. Rubber core. 3. Disc. 4. Crankshaft flange.

Electrical System

The electrical system has three separate circuits: the charging circuit, the starting circuit and the low amperage circuit. Some of the electrical system components are used in more than one circuit. The battery (batteries), circuit breaker, ammeter, cables and wires from the battery are all common in each of the circuits.

The charging circuit is in operation when the engine is running. An alternator makes electricity for the charging circuit. A voltage regulator in the circuit controls the electrical output to keep the battery at full charge.

The starting circuit is in operation only when the start switch is activated.

The starting circuit can have a glow plug for each cylinder of the diesel engine. Glow plugs are small heating units in the precombustion chambers. Glow plugs aid ignition of the fuel when the engine is started in temperatures that are low.

The low amperage circuit and the charging circuit are both connected to the same side of the ammeter. The starting circuit connects to the opposite side of the ammeter.

System Components

Alternator

The alternator is a three phase self-rectifying charging unit. The alternator is driven from an accessory drive pulley by a V-type belt.

The only part in the alternator assembly which has movement is the rotor. The rotor is held in position by ball bearings at both ends.


ALTERNATOR COMPONENTS
1. Brushes. 2. Stator. 3. Fan. 4. Slip rings. 5. Shaft nut. 6. Bearings. 7. Bearings. 8. Rotor.

Alternator Regulator

The regulator controls the alternator output according to the needs of the battery and the other components in the electrical system.


ALTERNATOR REGULATOR
1. Plug. 2. Connector.

Starting Motor

Two starting motors are used to turn the engine flywheel fast enough to get the engine running.


STARTING MOTOR
1. Field. 2. Solenoid. 3. Clutch. 4. Pinion. 5. Commutator. 6. Brush Assembly. 7. Armature.

Each starting motor has a solenoid. When the start switch is activated, electricity from the electrical system will cause the solenoid to move the starter pinion to engage with the ring gear on the flywheel of the engine. The starter pinion will engage with the ring gear before the electric contacts in the solenoid close the circuit between the battery and the starting motor. When the start switch is released, the starter pinion will move away from the ring gear of the flywheel.

Solenoid

A solenoid is a magnetic switch that uses low current to close a high current circuit. The solenoid has an electromagnet with a core (6) which moves. There are contacts (4) on the end of core (6). The contacts are held in the open position by spring (5) that pushes core (6) from the magnetic center of coil (1). Low current will energize coil (1) and make a magnetic field. The magnetic field pulls core (6) to the center of coil (1) and the contacts close.


SCHEMATIC OF A SOLENOID
1. Coil. 2. Switch terminal. 3. Battery terminal. 4. Contacts. 5. Spring. 6. Core. 7. Component terminal.

Magnetic Switch

A magnetic switch (relay) is used for each starter solenoid. Its operation electrically, is the same as the solenoid. Its function in the starter circuit is to reduce the low current load on the start switch and control low current to the solenoid.

Wiring Diagrams

A number of electrical systems can be used with these engines. Some systems have two starting motors. Other systems without electric starting motors are used with air starting and hydraulic starting.

Negative Ground Systems

These systems are used in applications where it is not necessary to prevent radio distortion and/or electrolysis of grounded components.

Insulated Systems

These systems are used in applications where removal of radio distortion is needed or where conditions can cause grounded components to be destroyed from electrolysis.

Caterpillar Information System:

D353 INDUSTRIAL & MARINE ENGINES Shut-Off Solenoids<BR> 3L2871 24V or 32V (Delco-Remy Number 1119817)
D353 INDUSTRIAL & MARINE ENGINES Alternator Regulators
D353 INDUSTRIAL & MARINE ENGINES Alternators<BR> 6L6590 and 6L6591 32V 45A (Delco-Remy Number 1117773)
D353 INDUSTRIAL & MARINE ENGINES Starter Solenoid<BR> 5L8595 32V (Delco-Remy Number 1119836); 6N5123 24V (Delco-Remy Number 1115544)
D353 INDUSTRIAL & MARINE ENGINES Starting Motor
D353 INDUSTRIAL & MARINE ENGINES Flywheel Housing Bore
D353 INDUSTRIAL & MARINE ENGINES Flywheel Housing Runout
D353 INDUSTRIAL & MARINE ENGINES Flywheel Runout
D353 INDUSTRIAL & MARINE ENGINES Flywheel Housing
D353 INDUSTRIAL & MARINE ENGINES Vibration Damper
D353 INDUSTRIAL & MARINE ENGINES Flywheel
D353 INDUSTRIAL & MARINE ENGINES Crankshaft
D353 INDUSTRIAL & MARINE ENGINES Testing And Adjusting
D353 INDUSTRIAL & MARINE ENGINES Introduction
D353 INDUSTRIAL & MARINE ENGINES Governor Drive<BR> (Part of 2N5892 for UG-8 Governor and 1N5403 for EG-3P Actuator)
D353 INDUSTRIAL & MARINE ENGINES Governor Drive<BR> (Part of 5L7789 for UG-8 Governor and 4N5404 for EG-3P Actuator)
D353 INDUSTRIAL & MARINE ENGINES Governor Linkage Adjustment For UG-8 Governor
D353 INDUSTRIAL & MARINE ENGINES Governor Air Actuator<BR> (2L6745)
D353 INDUSTRIAL & MARINE ENGINES Actuator Linkage Adjustment For EG-3P Actuator
D353 INDUSTRIAL & MARINE ENGINES Shutoff Solenoid<BR> 3L2871 24V or 32V (Delco-Remy Number 1119817)
D353 INDUSTRIAL & MARINE ENGINES Starting Motor<BR> 8L5939 32V (Delco-Remy Number 1109625)
D353 INDUSTRIAL & MARINE ENGINES Starter Solenoid<BR> 5L8595 32V (Delco-Remy Number 1119836)
D353 INDUSTRIAL & MARINE ENGINES Starting Motor (Early Automatic Start/Stop Systems)<BR> 8L5938 32V (Delco-Remy Number 1109953)
D353 INDUSTRIAL & MARINE ENGINES Starter Magnetic Switch (Early Automatic Start/Stop Systems)<BR> 5L5891 24V (Delco-Remy Number 1119867)
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