PERFORMANCE SCREEN 2 OF 2

PERFORMANCE SCREEN 1 OF 2

After the warning screens have been acknowledged the "Performance 1 of 2" screen will then appear on the display (illustration 21). This is the default screen. Pressing the right ARROW button will display the "Performance 2 of 2" screen (illustration 22).

Using the left and right ARROW buttons allows the operator to switch back and forth between the two Performance screens. Vital information about the machine's major systems may be easily monitored using these two screens and the in-dash Instrument Cluster.

- Hydraulic Oil Temperature

- Torque Converter Oil Temperature - Engine Oil Pressure

- Air Inlet Temperature - Fuel Level

- System Voltage

The Home Menu may displayed from any screen by pressing the HOME button.

INSTRUCTOR NOTE: For more detailed information about the new monitoring system and Advisor and how to access and use all of the options, refer to SERV1790,

"Caterpillar Monitoring and Display System with Advisor™ for Track-type Tractors."

ENGINE

The C15 ACERT™ technology engine is new for the D8T Track-type Tractor. The engine is equipped with Mechanical Electronic Unit Injection (MEUI), an Air To Air

AfterCooler (ATAAC), and a new electro-hydraulic demand fan system. The C15 engine also utilizes the A4 Engine Electronic Control Module (ECM), which is air cooled. The C15 is rated at 231.6 net kW (310 net horsepower) at 1850 rpm. The D8T uses a "constant net" power strategy. This means that at rated speed, and under full load, the tractor always delivers 231 kW (310 hp) at the flywheel, except during derates. When the demand fan is at maximum speed, the Engine ECM increases gross power to 259 kW (347 hp). At minimum fan speed, the Engine ECM maintains gross power at 243 kW (326 hp). This strategy maintains a constant net power regardless of fan requirements and provides fuel consumption benefits during low

ambient conditions.

The C15 engine is an in-line six-cylinder arrangement, with a displacement of 15.2 liters. Most of the service points for the C15 are located on the left side of the engine.

The C15 engine meets U.S. Environmental Protection Agency (EPA) Tier III Emissions Regulations for North America and Stage III European Emissions Regulations.

The C15 is functionally similar to the 3406E engine used in the D8R Series II. However, the Engine ECM and its software, the cam, the injectors, the crankshaft, the piston rods, the pistons, and a few other components are re-engineered, reflecting the change to ACERT technology. An electro-hydraulic demand fan is standard equipment for the D8T. The D8T may also be

equipped with an automatic/manual fan reversing feature for some applications.

The C15 ACERT technology engine specifications for the D8T Track-type Tractor are:

-Serial No. Prefix: LHX

-Performance Spec: 0K4648 (for North America), and 0K4147 (for E.U.) -Max Altitude: 3810 m (12,500 ft.) without derate

-Gross Power: 259 kW (347 hp) -Net Power: 231 kW (310 hp) -Full Load rpm: 1850

-High Idle rpm (full throttle, neutral): 2200 ± 10 (for North America), 2070 ± 10 (for E.U.) -Low Idle rpm: 700

NOTE: The C15 engine uses a "Ground Speed Governor" engine software strategy to reduce the potential for engine overspeed and to maintain a constant speed in downhill and uphill situations when there is little or no load on the blade. The Engine ECM constantly monitors engine speed and torque converter output speed to make the following adjustments.

- If the engine is at high idle while the machine is traveling downhill, the Engine ECM will automatically lower engine rpm to maintain the correct torque converter output speed. In uphill situations, the Engine ECM will automatically increase engine rpm to maintain the correct torque converter output speed, up to a maximum of 2200 rpm.

- If the engine is in an overspeed condition (2600+ engine rpms), the Power Train ECM will automatically apply the brakes (up to 8% of brake capacity) in an effort to slow the

machine. If this auto-braking strategy does not lower engine rpms to an acceptable level, Advisor will warn the operator to change the operating mode (downshift or manually apply the brakes).

- If the operator has set an intermediate engine speed using the decelerator and the high-low idle switch, this strategy is ignored in uphill situations.

On machines built for the E.U., the torque converter output speed target is

approximately 5% lower than those built for North America, due to more stringent noise requirements. Accordingly, the ground speed target is a bit slower, also. This will result in slightly slower speeds when "roading" the machine and when backing up.

Major service points accessible from the left side of the engine are:

1. coolant sampling port (S•O•S) 2. engine oil fill tube

3. engine oil filter and associated service points (discussed later in this presentation) 4. air filter access cover

5. engine oil dipstick

6. primary fuel filter and water separator and electric fuel priming pump

7. secondary fuel filter and associated sensors (discussed later in this presentation) 8. A4 Engine ECM

9. starter

10. prelube motor and pump (if equipped)

11. high-speed oil change connectors for engine oil and power train oil 1

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Major service points accessible from the right side of the engine are:

1. turbocharger

2. air conditioning compressor

3. thermostat (temperature regulator) housing 4. alternator

5. coolant flow switch 6. external engine oil cooler 7. power train oil cooler 8. block heater element

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Located on the left side and toward the rear of the engine is the 10-micron primary fuel filter (1).

The primary fuel filter contains a water separator which removes water from the fuel. Water in a high pressure fuel system can cause premature failure of the fuel injectors due to lack of

lubricity and corrosion.

Fuel is drawn from the primary fuel filter by the fuel pump (shown later) and is then returned to the 2-micron secondary fuel filter (2). The secondary fuel filter removes all contaminants that could damage the fuel injectors. Fuel filters should be replaced regularly, according to the guidelines on the D8T Operation and Maintenance Manual (SEBU7763) to ensure that clean fuel is always delivered to the fuel injectors.

The electric fuel priming pump (4) is integrated into the primary fuel filter base. It is activated by pushing the electric fuel priming pump switch (5). Also shown is the fuel system air purge valve (3), which is used to purge the priming pump of any air that might be introduced after changing the fuel filters. The fuel priming pump is used to fill the fuel filter housings after the filter elements have been replaced. The fuel priming pump is capable of forcing the air from the entire fuel system.

After the fuel filters have been replaced, activate the priming pump and then open the air purge valve. (Always place a suitable container under the purge valve outlet to catch any fuel that escapes through the valve.)

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produces enough pressure to force fuel past the bypass valve in the fuel transfer pump and past the fuel pressure regulator (check valve). Also note that the main disconnect switch must be turned to the ON position and the key start switch must be in the OFF position for the fuel priming pump to run.

Also visible in the illustration above is the block heater receptacle (6). 120V and 240V versions of the block heater are available.

Also shown is the auxiliary start receptacle (7), which may be used to supplement the batteries when the temperatures are extremely cold or the batteries are low.

The ether aid solenoid (8) is also shown in illustration 26 (the ether canister is not installed).

When the ether aid solenoid is energized, ether is injected into the intake manifold inlet tube (9).

The Engine ECM controls ether injection when the conditions warrant its use. The Engine ECM monitors the intake air temperature sensor and the coolant temperature sensor to determine when to inject ether. If the temperature of the engine coolant or the intake air is less than 0°C (32°F), AND the engine speed is greater than 35 rpm, but less than low idle speed (700 rpm), then ether injection will be activated. Once the engine starts and the low idle speed is attained, the Engine ECM then looks to the ether injection map (contained in the engine software) to determine how long to provide ether injection.

The status of the ether aid solenoid may be viewed through the Advisor Panel (Engine System Status screens) or by using Cat ET.

Installed in the top of the secondary fuel filter base are the following fuel system components:

1. fuel temperature sender

2. fuel pressure regulator (check valve) 3. fuel pressure sensor

4. secondary fuel filter bypass switch (differential pressure switch)

The status of the fuel temperature, the fuel pressure, and the state of the secondary fuel filter bypass switch may be viewed through the Advisor panel (Engine System Status screens) or through Cat ET.

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The fuel transfer pump (1) is located at the front left of the engine, near the bottom of the

engine. The fuel transfer pump is driven by the front gear train. Fuel is drawn from the primary fuel filter and water separator through the upper fuel line (2) by the fuel transfer pump and is returned to the secondary fuel filter through the lower fuel line (3).

The primary (crankshaft) engine speed/timing sensor (4) is located just below the fuel transfer pump. The crankshaft speed/timing sensor provides crankshaft speed and position information to the Engine ECM. This information is also shared with the Power Train ECM as engine speed information. The C15 engine has no engine output speed sensor at the flywheel housing. This is a change from the D8R Series II, which had an engine output speed sensor installed in the flywheel housing which provided engine speed information to the Power Train ECM.

The timing calibration probe adapter (7X1171) is threaded into the timing calibration port (5), after removing the plug. The timing calibration probe, or transducer (6V2197), is then inserted into the adapter. Maintain a 1 mm (.040") air gap between the end of the probe and the

machined surface of the crankshaft counterweight when positioning the probe. The probe will sense a notch that is machined in the crank counter-weight. Cable 7X1695 is used to connect the probe to the timing calibration connector (illustration 31).

The engine pre-lube pump (1) is driven by an electric motor (2). (The pre-lube pump is no longer driven by the starter motor.) If the machine is equipped with pre-lube, the pre-lube pump and motor are installed on the left side of the engine, just above the oil pan. Engine pre-lube is used to ensure that there is sufficient oil pressure throughout the engine oil system before allowing the starter to engage and start the engine. This strategy prevents premature wear of critical engine components. When the key start switch is moved to the START position, the prelube pump may run for a short time before the starter engages.

The Engine ECM determines when to activate the pre-lube pump by monitoring the engine oil pressure sensor. If the oil pressure is less than 30 kPa (4.4 psi) the Engine ECM will activate the pre-lube pump until the oil pressure reaches 30 kPa (4.4 psi), or for up to 45 seconds, whichever occurs first. To override this strategy, turn the key switch to the START position. Then cycle the key start switch to the OFF position and then back to the START position again within one second. This action will allow the starter to engage without cycling the pre-lube pump.

The ecology drain (3) for engine oil is located on the left side of the oil pan. The steel tube (4) to the rear of the pre-lube pump connects to the Quick-Evac connector for engine oil.

NOTE: When the lube cycle is activated, Advisor will inform the operator that pre-lube is activated and to keep the key start switch in the "START" position until the engine is running.

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The atmospheric pressure sensor (1) and the engine oil pressure sensor (2) are installed in a block that is located on the lower left side of the engine, between the pre-lube pump and the starter.

The status of these two pressure sensors may be viewed through the Advisor panel (Engine System Status screens) or through Cat ET. Engine oil pressure may also be viewed on the Performance Screen 2 of the Advisor display.

The starter (1) is located on the left side of the engine, and is mounted to the front side of the flywheel housing.

Just above the starter is the air cooled A4 Engine ECM (2). The timing probe connector (3) is fastened to the wiring harness coming from the J2/P2 connector (4). The J1/P1 connector (5) is a 70-pin connector and the J2/P2 connector is a 120-pin connector.

The hydraulic hose and fitting (6) supplies lube oil to the flywheel housing. The other end of the hose is connected to a fitting on the side of the torque converter oil inlet port, at the left rear of the torque converter housing. A small amount of power train oil flows through the hose to provide lubrication for the flywheel and pump drive gears. The power train scavenge pump returns the oil from the bottom of the flywheel housing to the power train main sump.

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Also accessible from the left side of the engine, and located just above the starter, is the cover for inserting the engine turning tool (1). Removing this cover allows the serviceman to insert the 9S9082 engine turning tool to manually turn the engine.

To find Top Dead Center (TDC) of cylinder number one, remove the plug in the TDC port (2), then insert the longer bolt from the cover (1) into the port (2). While applying light pressure to the bolt, turn the engine in the direction of engine rotation until the bolt drops into the hole machined in the front face of the flywheel. A spring-loaded timing pin (136-4632) may also be used to find TDC, instead of the long bolt from the cover.

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The intake air temperature sensor (1) is located on the left side of the engine, just below the primary fuel filter and water separator. The status of this pressure sensor may also be viewed through the Advisor panel (Engine System Status or Performance screen) or through Cat ET.

The "Crank-Without-Inject" connector (2) is fastened to the wiring harness just below and in front of the intake manifold. Removing the plug (3) from the "Crank-Without-Inject"

connector (2) and inserting the plug (4) at the left will electronically disable the fuel injectors.

This allows the engine to be turned (cranked) using the starter, but without the engine starting.

No fuel will be injected into the cylinders in this mode so that the engine cannot start and run.

The status of the "Crank-Without-Inject" feature may be viewed through the Advisor panel (Engine System Status screens) or through Cat ET.

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Located at the left front of the engine, are the following service points:

1. engine oil filter 2. engine oil filler tube

3. engine oil sampling port (S•O•S port) 4. engine oil pressure port

5. engine oil dipstick

NOTE: The engine oil pressure port tests the engine oil pressure after the oil is filtered.

The engine oil sampling port is positioned upstream of the oil filter so an oil sample reflects the cleanliness of the oil before the filter.

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The intake manifold air (boost) pressure sensor (1) is located at the upper left, and at the front of the engine, just ahead of the engine oil filter.

Also located here, and installed in the rear of the timing gear cover, is the secondary (camshaft) engine speed/timing sensor (2).

The status of the intake manifold pressure sensor may be viewed through the Advisor panel (Engine System Status screens) or through Cat ET.

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The coolant temperature sensor (1) is installed at the right front corner of the engine, in front of the water pump (2). The status of the coolant temperature sensor may be viewed through the Advisor panel (Engine System Status screens or Performance screen) or through Cat ET.

The water pump (2) is located behind and below the alternator, at the right front of the engine.

Just above the water pump is the thermostat (coolant temperature regulator) housing (3). Two thermostats are contained in the housing. The shutoff valve for the cab heater return line (4) and the shutoff valve for the cab heater supply line (5) are located to the rear of the thermostat housing. The coolant flow switch (6) is situated outboard from the thermostat housing and installed in the cast tube exiting the water pump.

The status of the coolant flow switch may be viewed through the Advisor panel (Engine System Status screens) or through Cat ET.

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Also accessible at the right front of the engine is the alternator (1) and the air-conditioning compressor (2). Just to the rear of the air-conditioning compressor is the turbocharger (3).

The turbocharger on the C15 ACERT technology engine uses a standard wastegate (4), which is operated by a vacuum line (5). The wastegate acts as a bypass valve for exhaust gasses. When the wastegate opens it allows some of the exhaust gasses to bypass the turbocharger. The wastegate limits boost pressure, which in turn, limits the maximum engine cylinder pressure.

The center section of the turbocharger is water cooled (line not visible) and is lubricated with engine oil, which is supplied through the hard steel tube (6).

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The oil-to-water type engine oil cooler (1) is located along the lower right side of the engine.

Oil from the oil filter enters the cooler at the oil inlet (2) and passes through tubes surrounded by engine coolant. The cooled oil then exits the cooler at the oil outlet (4) and enters the engine block at port (5).

When the engine is started and the oil is cold, some of the oil bypasses the engine oil cooler through the cooler bypass tube (3).

Coolant enters the engine oil cooler at the front (right, above) of the cooler and exits at the rear, where it then enters the power train oil cooler (6). After flowing around the oil filled tubes in the power train oil cooler, the coolant enters the right side of the engine block through a port (not visible) behind the power train oil cooler.

NOTE: When troubleshooting the cooling system it must be understood that both the engine oil cooler and the power train oil cooler are heat sources that raise the

temperature of the coolant before it enters the engine block.

The turbo inlet pressure sensor (1) is installed at the outlet of the air filter canister and is accessible from the right side of the engine.

The turbo inlet air pressure sensor is used to determine air filter restriction. The Engine ECM compares the turbo inlet air pressure to the atmospheric air pressure and calculates a pressure differential between the two pressures. If the pressure differential is too great, it can indicate that the air filter is clogged and needs to be replaced.

Also visible in this illustration is the dust ejector tube (2) that connects the intake air precleaner to the muffler.

The status of the turbo inlet air pressure sensor may be viewed through the Advisor panel (Engine System Status screens) or through Cat ET.

Fuel System

Fuel is drawn from the fuel tank through the primary fuel filter (10-micron) and water separator by a gear-type fuel transfer pump. The fuel transfer pump then directs the fuel through the secondary fuel filter (2-micron).

From the secondary fuel filter,the fuel is then directed to the cylinder head and into the fuel gallery, where it is made available to each of the six MEUI fuel injectors. Any excess fuel not injected leaves the cylinder head. From the cylinder head, the fuel is directed back to the fuel tank through the fuel pressure regulator, which maintains fuel pressure of 558 ± 50 kPa (81 ± 7 psi). The fuel pressure regulator is a check valve that is installed in the secondary fuel filter base.

From the fuel pressure regulator, the excess fuel flow returns to the fuel tank. The ratio of fuel between combustion and fuel returned to tank is approximately 3:1 (i.e. four times the volume

In document Serv 1789 (Page 31-61)