Milton CAT 312D L User Manual

312D/312D L

Hydraulic Excavators

®

Engine

Engine Model Cat
Net Power (SAE J1349) 67 kW 90 hp
Gross Power 72 kW 97 hp

®

C4.2 ACERT™

Weights

Operating Weight – Standard Undercarriage 12 920 kg 28,480 lb
Operating Weight – Long Undercarriage 13 450 kg 29,650 lb

Features

Comfortable Operator Station

Spacious and quiet, this world class cab
lets the operator focus on performance
and production.

Industry-Leading Performance

The 312D with a Cat® C4.2 ACERT™ engine
and overall system efficiency delivers
industry-leading productivity.

Maximum Versatility

Easily configure a large variety of work tools
with the Cat Tool Control System.

Proven Reliability

Caterpillar® design and manufacturing
techniques provide maximum uptime with
outstanding durability and service life.

Low Emissions Engine

Move material using less fuel with the
Cat 4.2 ACERT engine. It meets Tier 3 and
EU Stage IIIA emissions while maintaining
the power and performance expected
from Caterpillar.

Contents

Operator Station . . . . . . . . . . . . . . . . . . . . .3

Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Hydraulics . . . . . . . . . . . . . . . . . . . . . . . . . .5

Undercarriage and Structures . . . . . . . . .6

Front Linkage . . . . . . . . . . . . . . . . . . . . . . . .6

Versatility . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Serviceability. . . . . . . . . . . . . . . . . . . . . . . .8

Technology Products . . . . . . . . . . . . . . . . .9

Customer Support. . . . . . . . . . . . . . . . . . .10

Specifications . . . . . . . . . . . . . . . . . . . . . .11

Standard and Optional Equipment. . . . .21

Achieve high productivity and lower operating costs with
the Cat

®

312D Hydraulic Excavator. Unmatched versatility,
improved controllability, easy operation and a comfortable,
redesigned operator station help make the 312D an
industry-leading performer.

Operator Station

Enhanced comfort, operation and visibility

Experience a spacious, quiet and comfortable operator station.
The cab is pressurized to 50 Pa to reduce the amount of dust
that enters the cab, keeping the operator comfortable the entire
shift, while assuring high productivity during long work days.

• The comfortable seat adjusts to suit the operator’s size and
weight. Available as an option is the air suspension seat.

• Standard air conditioning with automatic climate control
adjusts temperature and airflow.

• Low effort joystick controls are designed to match the
operator’s natural wrist and arm position. Joysticks can be
operated with arms on the adjustable armrests. The horizontal
and vertical strokes are designed to reduce fatigue.

Prestart Check and Monitor Display

Prior to starting the machine, the system checks for low engine
oil, hydraulic oil and engine coolant fluid levels and warns the
operator through a color Liquid Crystal Display (LCD) monitor.
The LCD monitor displays vital operating and performance
information, in 28 different languages, for operator convenience.

Cab Exterior

The 312D provides a new cab design that allows the Falling
Object Guard System (FOGS) to be bolted directly to the cab,
at the factory or as an attachment, enabling the machine to meet
specifications and job site requirements. The cab shell is attached
to the frame with viscous rubber cab mounts that dampen
vibrations and sound levels to enhance operator comfort.

Machine Security System

An optional Machine Security System (MSS) utilizes a
programmable key, deterring theft, vandalism and unauthorized
usage. MSS uses electronically coded keys selected by the
customer to limit usage by individuals or time parameters.

3

Engine

Delivering the most work per liter/gallon of fuel consumed

The Cat® C4.2 engine with ACERT™ Technology optimizes performance and meets U.S. EPA Tier 3 and EU Stage IIIA regulations.
In conjunction with integrated electronics, ACERT Technology reduces emissions during the combustion process by using advanced
technology in the air and fuel systems. The Cat C4.2 engine delivers exceptional power, allowing more hydraulic pressure to drive
productivity and reduce your cost per ton of material moved.

Automatic Engine Control and Fuel Delivery

A two-stage control with one-touch command maximizes fuel efficiency and reduces sound levels. Fuel delivery is managed by the
ADEM™ A4 Engine Controller for the best performance per liter (gallon) of fuel used. Flexible fuel mapping allows the engine to
respond quickly to varying application needs.

Crankshaft and Pistons

A forged, one-piece, induction hardened crankshaft enhances balance, decreases vibration and improves abrasion resistance.
Heat resistant, aluminum alloy pistons have a short compression height for greater efficiency and longer life.

Economy Mode

Available as standard, economy mode allows you to balance the demands of performance and fuel economy while maintaining
the breakout forces and lift capacity enjoyed at standard power.

4

Hydraulics

Low effort and precise control for highly efficient performance

Outstanding Performance

With two percent more hydraulic pressure for additional lift
and breakout forces, the 312D hydraulic system is designed
for high efficiency and performance. Auxiliary hydraulic and
electrical lines are routed to the boom foot making installation
of hydraulic circuits much easier. This compact design utilizes
short tubes and lines, reducing friction and pressure drops,
resulting in a more efficient use of power.

• Hydraulic snubbers at the rod end of the boom cylinders and
both ends of the stick cylinders cushion shock, reduce sound
and increase cylinder life.

• Flow is reduced to a minimum when controls are in neutral
to reduce fuel consumption and extend component life.

• Electronic Under Speed Control electronically adjusts pump
output to not exceed engine power, preventing the need to
reserve engine power to avoid engine stalls.

• Hydraulic Cross-Sensing System uses two hydraulic pumps up
to 100 percent of engine power under all operating conditions,
improving productivity with faster implement speeds and
quicker, stronger pivot turns.

Boom and Stick Regeneration Circuit

The boom and stick regeneration circuit saves energy during
boom-down and stick-in operation, increasing efficiency and
lowering operating costs.

Easy Operation

Work mode and power mode switches have been eliminated
making full power available at all times. Operators do not need
to learn different modes, an automatic boom and swing priority
function automatically selects the best mode based on joystick
movement.

5

Undercarriage and Structures

Strong, stable and easy to maneuver

Caterpillar uses advanced engineering and software to analyze
all structures, creating a durable, reliable machine for the
toughest applications. More than 70 percent of the structural
welds are robotic and achieve additional penetration over
manual welds. These structural components and undercarriage
are the backbone of the machine’s durability.

Carbody Design

X-shaped, box section carbody provides excellent resistance to
torsional bending. Robot-welded track roller frames are press­formed, pentagonal units that deliver exceptional strength and
service life. Idler and center guards (standard for LC option)
are available to help maintain track alignment when traveling
or working on slopes.

Grease Lubricated Track

Grease lubricated track seals protect the track link and deliver
long track link pin and bushing inner wear.

Front Linkage

Reliable, durable and versatile

Built for performance and long service life, Cat booms and
sticks are welded, box-section structures with thick multi­plate high strength steel fabrications. Service intervals are
extended with self-lubricating bearings that resist corrosion
and galling for superior durability.

Boom

The boom is designed for maximum digging capability and
is robotic welded to ensure consistent quality. This allows
excellent all-around versatility and a large working envelope.

Travel Motors

Travel motors with automatic speed selection let the 312D
automatically change up and down from high and low speeds
in a smooth, controlled manner.

Stick

Three stick options are available to meet your application
needs and increase performance and productivity. A new

2.8 m (9'2") intermediate stick is available to provide long
reach and increased digging and lifting capability.

Versatility

More options for more work

Work Tools

Caterpillar offers a variety of work tools, including hammers,
thumbs, grapples, multi-processors, shears, pulverizers and
vibratory compactors to fit your application needs. Additionally,
a wide range of buckets are available to optimize machine
performance.

Auxiliary hydraulic and electrical lines are routed to the
boom foot for easier installation of auxiliary hydraulic circuits,
therefore reducing time, parts and cost required to add a
work tool.

Hydraulic Pin Grabber

An optional hydraulic pin grabber is available to pick up a
wide variety of work tools without having to leave the cab,
thus maximizing productivity.

Enhanced Systems

Work tool functionality has increased the versatility of the
machine with the enhancement of the following:

• An optional Combined System enables one or two pump flow
in one or two directions. With this system, only one hydraulic
circuit is required.

• The Tool Control System stores up to 10 different tool settings
through the in-cab display monitor. Cat Work Tools are
selectable with preset flows and pressures.

• Offered as an option, the Priority Flow System provides
one-way or two-way hydraulic work tools, such as a mower,
priority for hydraulic flow.

• Medium Pressure Circuit is available as an attachment for
work tools requiring moderate hydraulic flow, such as a
rotating bucket or shears.

7

Serviceability

Simplified service and maintenance saves time and money

Designed with the service technician in mind, many service locations are at ground level so critical maintenance can be done quickly
and efficiently. Longer maintenance intervals reduce cost and increase machine availability.

• LCD monitor has the capability to memorize working hours for filters, fluids, components and work tools. Working time histories
and recommended change intervals can be displayed.

• Oil level gauge, fuel filter and priming pump are conveniently located on engine structure for easy maintenance.

• An optional electronic fuel water sensor is available to alert the operator when the water level is high.

• Product Link assists with fleet management by tracking hours, location and product health.

• New anti-skid plates over the top of the storage box and upper structure help prevent slipping and mud from falling into the
upper structure.

Sampling Ports

Equipped with S·O·SSM sampling ports and test ports for hydraulics, engine oil and coolant for quick diagnostics. A test connection
for the Cat Electronic Technician (Cat ET) service tool is now located in the cab.

Air Cleaner

A double-layered filter core in the radial seal air filter gives more efficient filtration. A warning is displayed on the monitor when
dust accumulates above a preset level. This filter is conveniently located in the compartment behind the cab. An optional pre-cleaner
is also available to extend filter life and reduce maintenance costs.

Capsule Filter

Capsule-type, hydraulic return filter is accessible from outside the tank and prevents contaminants from entering the system when
changing the hydraulic oil.

Radiator Compartment

Horizontal air conditioner condenser swings out for easy cleaning. Removable screens are located in front of the radiator and
hydraulic cooler, reducing cleaning time and effort.

8