ENGINE AR-PRIMARY 1791789 - Caterpillar

Machine Appearance
The appearance of the machines is being standardized to display a common marking scheme for all 300 Family Excavators. The model numbers, corporate design and striping are uniform for all models regardless of manufacturing source.
Cab Improvements
The following operator comfort details will be included across the listed models in the 300 Family line.
* Improved radio "On/Off" switch location if radio equipped.* Relocation of the heater/ air conditioning control.* Replace the heater/ air conditioner with an improved unit to provide increased heating/ cooling capability.* New implement control levers (1) with integral three-button switches in each lever. These are only used with auxiliary circuits (attachment).* Improved appearance and easy-to-grasp hydraulic activation control lever (2).* Added a second service meter for the one-way circuit to provide a way to measure true operating hours for hydraulic hammers. This service meter is located on the control panel where the heater control was previously positioned.
Illustration 1. View of cab improvements. (1) Implement control levers. (2) Hydraulic activation control lever.With the introduction of the three-button switch in the implement control levers, the auxiliary (third) pedal will not be used to activate the one-way circuit.
The buttons may be used to control the actuation and speed of the hydraulic hammer, the actuation of the rotator circuit, or to pressurize the auxiliary circuits on the boom, if equipped. The horn switch is now relocated to the lower button in the left implement control lever and the manual low idle switch is located on the lower button in the right implement control lever.
Illustration 2. Implement control levers with three button switches in each lever.Maintainability
Maintenance improvements for the 320 Excavators include adding a drain-cock on the engine oil reservoir, improved drain for the water separator (also 322 and 325), and relocation of the batteries to provide more utility storage. The addition of a suction connection line for the auxiliary pump is now on all listed machines. The 320 Excavators have a latchable radiator door for easier access.
Illustration 3. Addition of engine oil drain cock.
Illustration 4. Relocated water separator for easier draining.Convenience and Practical Improvements
All machines will provide for automatic prevention of high engine rpm during start-up, adoption of a Power Mode Switch/Work Mode Switch (PMS/WMS) code memory, a fold-type mirror for easy transportation, and reduced rattling of bucket teeth.
New software in the EPC will prevent the governor from providing the required fuel to the engine until it is adequately lubricated. Before, if the engine was stopped and restarted with the governor selector dial at position "10" and the "One Touch Low Idle" function activated, the engine would return to the high idle "10" speed.
A memory incorporated into the Electronic Power Control (EPC) will retain the previous Work Mode and Power Mode settings when the machine was stopped. Previously, work and power modes were reset to default levels ("PM2" and "Boom Priority"). The electronic monitor is changed to display pictograms instead of words.
Improvements with the listed machines include an overload warning device as an attachment option or when the machines are