Usage:
Proper operation and maintenance are key factors in obtaining the maximum life and economy of a truck engine. Follow the directions in this guide for trouble-free, economical truck engine operation.
After the engine starts, allow it to idle 3 to 5 minutes, or until the water temperature has begun to rise.
Select the lowest gear for a smooth, easy start without slipping the clutch. Rapid engine acceleration causes high fuel consumption and heavy exhaust smoke, with no increase in vehicle performance. For the best performance, do not skip gears when loaded.
Shift early in the RPM rise. When the engine speed approaches 80% of rated RPM, shift into the next highest gear.
Continue to upshift until cruising speed is reached. For the best fuel economy, use the highest gear that will pull the load. The governor will maintain a constant speed without accelerator pedal correction.
On upgrades, begin downshifting when the engine RPM starts to approach peak torque speed (1200 RPM). Fuel economy will be best if you let the engine lug back to around this speed before you downshift. Downshift until a gear is reached in which the engine will pull the load. For best performance, downshift when the engine RPM falls to 60% of rated RPM. Allow the engine to lug down if you can make it to the top of a hill without downshifting. Modern Caterpillar engines are not damaged by lugging.
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On a downgrade, do not coast or put the transmission in neutral. Select the correct gear to keep the engine speed below high idle, and use the BrakeSaver and/or brakes to limit the speed of the vehicle. A simple rule to follow is to select the same gear that would be used to go up the grade. Do not allow the engine speed to exceed high idle. |
Cold Weather Operation
If the engine is in good mechanical condition, and the precautions necessary for cold weather operation are taken, ordinary cold weather will not cause difficulty in starting, or loss of efficiency.
If the engine fails to start, and smoke is coming from the exhaust, turn the switch to the heat position for a longer period. If no smoke is coming from the exhaust, prime the fuel system.
LUBRICANTS: When it becomes necessary to start the engine in temperatures below 32°F, engine lubricants of lower viscosity should be used.
COOLANT: When the temperature is below freezing, use sufficient antifreeze solution in the cooling system to prevent freezing.
ELECTRICAL EQUIPMENT: During cold weather, give more attention to the condition of the battery. Test it frequently to assure sufficient power for starting. All switches and connections in the electrical system should be inspected, and kept in good condition, to prevent losses through improper contacts.
FUEL: Cloud point is the temperature at which wax crystals become visible, which is generally above the pour point of the fuel. To keep the fuel filter elements from plugging with wax crystals, the cloud point should be no higher than the lowest atmospheric temperature at which the engine must start.
Fuel heaters are available which will permit the use of fuel with a higher than recommended cloud point.
Altitude Operation
Turbocharger speed is determined by the fuel rack setting; the high idle speed and the altitude at which the engine is operated. The rack and high idle speed settings have been established to permit the engine to be operated at the altitude marked on the information plate.
If the engine is operated above the specified altitude, turbocharger damage can result.
The governor housing and turbocharger are sealed for your protection. Changes to the fuel rack setting, or high idle speed, should be made only by an authorized Caterpillar engine dealer.
Jacobs Engine Brake
Operation
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The Jacobs Engine Brake should not be used as a primary or service brake. |
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The Jacobs Engine Brake is a hydraulic engine attachment that converts a diesel engine into an air compressor. When converted to a power absorbing air compressor, the engine becomes an effective vehicle retarder. This will result in less wear on brake drums and linings.
Operating Controls
The Jacobs Engine Brake consists of a dash switch, a clutch switch and a throttle switch. These three switches must be closed in order to transfer power to the engine brake housing (operate the brake). Vehicles equipped with automatic transmissions may be equipped with a variation of this control system.
On some applications a multiposition switch is used to provide variable retarding capability. Operators should become familiar with the controls used on their vehicles.
NOTE: The Jacobs Engine Brake reacts quickly. It should activate or deactivate in less than 1/4 of a second.
Since the Jacobs Engine Brake is most effective at rated engine speeds, gear selection is very important. Gearing down the vehicle, within the limits of rated engine speed, makes the engine brake a more effective retarder. Maximum retarding occurs with the selection of the lowest gear that does not exceed rated engine speed.