Usage:
Gauges And Indicators
Oil Pressure Gauge
Oil pressure is normally greater after starting. As the oil warms, oil pressure decreases. As engine speed decreases, oil pressure decreases. At low idle, hot oil should register near the middle range of the gauge scale. Stop the engine and determine the cause if there is no oil pressure, or if the indicator fluctuates.
If the gauge reading fluctuates after the load is stable:
- 1. Remove the load.
- 2. Reduce engine speed to low idle.
- 3. Observe the oil level. Maintain the oil level between the ADD and FULL mark on the dipstick. If the reading continues to fluctuate when the oil level is correct, stop engine and call your Caterpillar dealer.
Engine Jacket Water Temperature Gauge
Operating temperature is maintained by water temperature regulators and radiator shutters. High coolant temperatures results when the cooling system does not dissipate engine heat properly. If overheating occurs, have the cooling system and radiators inspected.
If the operating temperature is below the opening temperature of the water temperature regulators, have the regulators checked.
The engine should operate within the NORMAL (green) range. If the engine is operating in the (red) range and steam becomes apparent:
- 1. Reduce the load and engine RPM.
- 2. Inspect for coolant leaks.
- 3. Determine if the engine must be shut down immediately; or if the engine can be safely cooled by reducing the load.
See COOLING SYSTEM MAINTENANCE INSTRUCTIONS.
| NOTICE |
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Do not add cold water to a hot engine: Cracking of engine components may occur. Allow the engine to cool, then add coolant. |
If the temperature gauge reading continuously registers in or near the cold range (white) while operating under load, have the following checks made:
- 1. Have the water temperature gauge checked for accuracy.
- 2. Have the temperature regulators removed and checked for proper temperature range. Replace regulators if necessary.
See COOLING SYSTEM MAINTENANCE INSTRUCTIONS.
Fuel Pressure Gauge
The fuel pressure gauge indicates pressure of the fuel pumped to the engine injection pumps. As the filters collect dirt, the fuel pressure drops until the gauge registers in the OUT range and engine performance decreases. When this occurs, clean the primary fuel filter. If low fuel pressure is still indicated, replace the fuel filter elements.
See the FUEL SYSTEM MAINTENANCE INSTRUCTIONS.
Ammeter
The ammeter should register in the charging range when the engine is running above low idle. If the gauge registers a discharge with an increase in engine speed, shut off the engine and determine the cause.
Air Cleaner Service Indicator
When the gauge indicator locks in the red range, service the air cleaner. With the engine stopped; see AIR INDUCTION AND EXHAUST SYSTEM MAINTENANCE INSTRUCTIONS.
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Shut the engine down if work on or around the engine is required. |
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Safety Alarms And Shutoff Devices
Electric Safety Alarm Operation
When a fault condition occurs-either high water temperature or low oil pressure-a microswitch in the sensing unit is actuated and completes a circuit to either a light, a bell or a horn. The light or sound warns the operator the engine must be stopped to prevent damage to the engine.
The high water temperature alarm switch is located in the regulator housing. The sensor must be in contact with the coolant in order to operate. A low coolant level will not actuate the switch.
The oil pressure alarm is energized when the oil pressure falls below the safe operating limits. For this reason, it may be desirable to turn the alarm to the OFF position when stopping the engine. The alarm must be turned to the OFF position before starting in order to allow the engine to start. The knob will move by itself to the RUN position after normal oil pressure is reached.
Mechanical Safety Shutoff
The mechanical safety shutoff device is mechanically driven and shuts off the fuel when either an overspeed or a low oil pressure condition exists. The shutoff mounts in the vee of the engine to the rear of the governor.
To protect the engine against operating with insufficient oil pressure, a gear driven slide is held from the engine driven worm shaft by normal oil pressure. If oil pressure drops below safe limits, the slide engages the revolving worm shaft and is propelled against a latching mechanism. The latch disengages, a spring-loaded rod strikes against the fuel rack and moves the fuel rack to the fuel off position. The engine will stop.
If sufficient oil pressure does not develop after starting, the engine will run approximately 7 seconds at operating speed and then will shut down. Therefore, check the oil pressure gauge reading immediately after starting.
1. Slide
2. Overspeed Carrier
3. Worm Shaft
4. Latch
5. Spring-loaded Rod
MECHANICAL SHUTOFF CROSS SECTION
To protect the engine against overspeeding, a spring-loaded weight, rotated by an engine gear train, is forced outward by centrifugal force. The weight strikes the latch mechanism discussed above. The latch disengages, the spring-loaded rod strikes against the rack and moves it to the fuel off position. The engine will stop.
By pressing the emergency stop button, the overspeed weight is released, the weight strikes the latch mechanism, and the spring-loaded rod strikes the rack, and moves it to the fuel off position; stopping the engine.
Safety Shutoff Reset Controls
After either mechanical shutoff device has stopped the engine, the shutoff controls must be reset before the fuel rack can be moved from the shutoff position and the engine started. First, push down on the reset button, then push the reset lever until the safety mechanism latches.
PUSHING RESET BUTTON
PUSHING RESET LEVER
If the reset lever does not return to its original position after latching the safety mechanism, check the cable for kinks or other internal resistance. The cable must move freely.
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DO NOT use any emergency shutoff control for normal shut down. The emergency shutoff controls are for emergencies only. |
Safety Shutoff Testing
Shutoff devices operate only when an abnormal condition exists, therefore, it is impossible to know if they are in working condition during normal operation. Since it is important that they will operate when necessary, have the shutoff devices checked every 6 months by your Caterpillar dealer or authorized personnel.
Do not use these shutoff devices for normal engine stopping. Such use may cause failure of these parts.
Determining Cause For A Shutdown
Anytime the engine is shut down by the safety circuit, the cause must be determined and corrective measures must be taken before starting the engine.
High Water Temperature
- 1. Determine if the locomotive is overloaded in relation to tonnage being pulled. High altitude or hot air entering the radiator can create an over-heated engine condition for an otherwise normal load.
- 2. Check the radiator fan drive.
- 3. Check the water level. Low water level will not shut the engine down, but may contribute to other failures.
- 4. Check shutter operation. Dirt or objects may prevent the shutters from properly opening.
- 5. Check the objects obstructing air flow through the radiator.
- 6. Check for faulty water pump operation, collapsed hoses, failed shut temperature regulators, or dirty cooling system.
Low Oil Pressure
- 1. Check the oil level. With the engine stopped, the oil level must be between the ADD and FULL mark. If oil level is low, determine the cause.
- 2. Check for new, wet oil accumulations at all gasketed joints. Check for leaks.
- 3. If visual checks cannot determine the cause, crank the engine with fuel off. If hard cranking or unusual noises are heard, immediately stop cranking. Have internal checks made on the engine.
- 4. Check for excessive smoke in the exhaust gasses.
- 5. Check for excessive blow-by.