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Mini Excavators

Caterpillar serves all regions of the world so we build many different configurations of hydraulic excavators. Your Cat® dealer has exact machine specifications available in your area to help you choose what will best meet your needs.

304E CR Hydraulic Excavator

The Cat 304E CR delivers high performance in a compact radius design to help you work in the tightest applications.

  • Specification Summary

  • Engine ModelCat® C2.4
  • Net Power30.0 kW
  • Gross Power31.2 kW
  • Operating Weight3854.0 kg
  • Operating Weight with Cab4009.0 kg
  • Product Brochure


Product Details


Engine Model Cat® C2.4
Net Power 30.0 kW
Gross Power 31.2 kW


Operating Weight 3854.0 kg
Operating Weight with Cab 4009.0 kg


Max digging depth - standard stick 3130.0 mm
Max reach ground level - standard stick 5350.0 mm
Height over cab 2500.0 mm
Max cutting height - long stick 5070.0 mm
Max cutting height - standard stick 4980.0 mm
Max dump height - long stick 3690.0 mm
Max dump height - standard stick 3590.0 mm
Max horizontal reach - long stick 5470.0 mm
Max horizontal reach - standard stick 5220.0 mm
Max vertical dig depth - long stick 2560.0 mm
Max vertical dig depth - standard stick 2420.0 mm
Shipping Height 2500.0 mm
Shipping Length 4820.0 mm
Track Shoe Width 350.0 mm
Transport Width 1950.0 mm

Engine Dimensions

Bore 87.0 mm
Stroke 102.4 mm
Displacement 2.4 L

Travel System

Max traction force - high speed 16.8 kN
Max traction force - low speed 30.8 kN
Travel Speed - High 4.6 km/h
Travel Speed - Low 2.6 km/h

MSC Comments

MSC Spec Date 3/06

Hydraulic System

Operating Pressure - Equipment 245.0 bar
Digging Forces - Stick (standard) 21.6 kN
Digging Force - Stick (long) 19.5 kN
Digging Force - Bucket 37.8 kN
Operating Pressure - Travel 245.0 bar
Operating Pressure - Swing 181.0 bar
Auxiliary circuit - primary 60.0 L/min
Auxiliary circuit - secondary 27.0 L/min

Swing System

Machine Swing Speed 9.0 RPM
Boom swing - left (without stop) 80.0 Degrees
Boom swing - left (with stop) 55.0 Degrees
Boom Swing - Right 50.0 Degrees


Width 1950.0 mm
Height 325.0 mm
Dig Depth 470.0 mm
Lift Height 400.0 mm

Service Refill Capacities

Cooling System 6.4 L
Engine Oil 9.5 L
Hydraulic Tank 42.3 L
Fuel Tank 46.0 L
Hydraulic System 65.0 L


Complete Operation, Maintenance, Performance And Security System.

COMPASS Display Panel

Unlock the new features and experience the value of the exclusive COMPASS control panel on the new E series Excavators. The brand new Complete Operation, Maintenance, Performance and Security System on the Caterpillar E series mini hydraulic excavators was specifically designed by Caterpillar for compact excavators. It adds several new features to the machines increasing the amount of customer value:
  • A Standard Anti-theft Security System
  • Adjustable Work Tool Auxiliary Flow Control
  • Continuous Flow
  • Economy Mode - save up to 20% fuel while maintaining high productivity with the push of a button.

Operator Station

Superior comfort to keep you productive throughout the work day.

Comfortable Working Environment

Spacious and comfortable operator station with excellent visibility and legroom keeps the operator comfortable and reduces fatigue. Standard features include:
  • Reclining suspension seat with adjustable wrist rests.
  • Pilot operated controls on all services including travel levers and dozer functions.
  • Two post canopy design for better visibility to the work area.
  • A pattern control changer (not available in all regions) is accessible from the cab to switch between excavator and backhoe style controls.
  • Ample storage space under the seat that can be locked for added security.

Optional Enclosed Cab

For even greater operator comfort, an enclosed cab is available as an option and features:
  • Sealed cab with heat and optional air conditioning to keep you comfortable in a wide range of conditions.
  • Radio ready with speakers and easy radio installation.
  • Removable lower front window and sliding windows for excellent overall visibility.
  • Gas assisted front window slides up with minimal effort.
  • Sliding door system offers good access and maintains the machine’s compact dimensions, reducing the risk of damage.

Joystick Controls

The boom swing and auxiliary hydraulic functions are located at your fingertips providing smooth, easy operation. These joystick mounted controls deliver more productivity through precise movement of the boom swing and auxiliary functions. They also eliminate foot pedals and free up the floor for more room for the operator’s feet. 100% pilot controls provide consistent flow and pressure throughout the life of the machine. This also allows all controls to be locked out while starting the machine and when the safety lockout bar is in the up position.


Powerful digging with precise control.


All four E Series models feature increased stability, while maintaining the compact radius design. This increased stability leads to more productivity and versatility through the use of heavier work tools and the optional long stick.

Fast, Powerful Digging with Load Sensing Hydraulics

High digging forces and fast cycle times deliver the productivity that your job demands. Load sensing hydraulics optimize flow for smooth, powerful performance and increased fuel efficiency.


High performance power train provides optimized engine horsepower and strong performance. Engine meets U.S. EPA Tier 4 Interim and EU Stage IIIA emissions requirements. Automatic engine idle automatically lowers engine revolutions when not in use to conserve fuel and lower environmental noise and emissions. The E-Series models feature an engine kill switch conveniently located in the cab and accessible from ground level.

Automatic Two Speed

With the standard automatic two speed feature, the machine will automatically balance high speed and torque travel requirements based on the conditions to give the operator the optimum speed and control. The machine can be put in low gear if slower travel is desired while in tight conditions.

200 Degree Bucket Rotation

Industry leading bucket rotation of over 200 degrees provides greater material retention during truck loading. It also allows for easier vertical wall digging without having to reposition the machine.

Zero Tail Swing

Work in the tightest areas.

Zero Tail Swing

The E Series compact radius design features a zero tail swing where the radius of the upper body stays entirely within the width of the undercarriage.

Coupler and Work Tool Options

New coupler design and multiple work tools increase versatility.


The E-Series is available with a mechanical pin-grabber or a hydraulic pin-grabber quick coupler option. The coupler design uses a wedge to keep the tool secure to the coupler, reducing wear and maintaining a tight fit through the life of the coupler. The hydraulic coupler allows the operator to change tools without leaving the comfort of the cab.

Wide Range of Work Tools

A wide range of Cat Work Tools have been designed specifically for the Cat Mini Hydraulic Excavators to maximize machine performance. Available work tools include:
  • Buckets (heavy duty and heavy duty capacity)
  • Tilting, Ditch Cleaning Buckets
  • Hydraulic Hammers
  • Augers
  • Thumbs (not available in all regions)
  • Vibratory Compactors
  • Quick Coupler

Standard Thumb Ready Sticks (optional in Europe)

Machines come standard with stick mounted brackets, ready to fit a hydraulic thumb for even greater machine versatility. A factory installed bracket and relief valve make hydraulic thumb installation simple and cost-effective.

Standard Auxiliary Lines and Accumulator

One-way and two-way auxiliary lines (combined function), including quick connections, are fitted as standard equipment so the machine comes ready to work. A standard accumulator allows for auxiliary pressure to be released, making connecting and disconnecting work tools safer and easier.

Dozer Blade

Standard dozer blade maximizes productivity.

Simple Dozer Control with Float Function

The dozer function is pilot controlled from inside the cab, providing smooth, proportional operation. The standard float function is enabled by pushing the lever fully forward into the detent position. Cleanup and backfilling is easier since the operator does not have to adjust the blade height during travel.

Excellent Blade Visibility

Visibility to the blade is excellent in any position, allowing the blade to be positioned behind the operator and away from the front linkage for better access when back dragging and finishing in tight areas.

Angle Blade Option

Increase machine versatility with the Cat angle dozer blade. Built for strength and durability, the hydraulic angle blade features a hardened steel wear edge and good protection to cylinders and hydraulic lines. The angle blade can be positioned straight ahead or angled up to 25 degrees to the left or right. This reduces the number of times required to back up and reposition when backfilling so you can finish the job faster. All functions of the blade are controlled with one joystick using a proportional roller switch for the angle function.


Stability and durability.

Rubber Track

The standard rubber track lets you work on multiple surfaces such as grass, pavement or stone without damaging the surface or machine.


Simplified service and maintenance save you time and money.

Easy Service

Convenient service features make maintenance easy, reducing your downtime:
  • Lifting side hood allows access to air filter, main implement valve, 1-way/2-way auxiliary flow selector, accumulator, fuel filter and hydraulic tank. This eliminates the need to lift the cab when maintaining and servicing the machine.
  • Swing out rear door provides access to major components and service points including engine oil check and fill, vertically mounted engine oil filter, starter motor and alternator.
  • Easy access to the radiator and oil cooler results in simplified cleaning and reduced maintenance times.
  • SOSSM oil sampling valve allows easy sampling of the hydraulic fluid for preventative maintenance.
  • 500 hour engine oil and filter change period reduces operating costs and machine downtime.

Customer Support

Support you can count on.

Superior Dealer Services

Your Cat dealer is ready to assist you with your purchase decision and everything after.
  • Financing packages are flexible to meet your needs.
  • Unmatched parts availability keeps you working.
  • Make comparisons of machines, with estimates of component life, preventative maintenance and cost of production.
  • Your Cat dealer can evaluate the cost to repair, rebuild and replace your machine.
  • For more information on Cat products, dealer services and industry solutions, visit www.cat.com.
  • 1-way and 2-way (combined function) auxiliary hydraulic lines
    • Adjustable wrist rests
      • Alternator
        • Automatic engine idle
          • Automatic swing park brake
            • Automatic two speed travel
              • Auxiliary line quick disconnects
                • Boom cylinder guard
                  • Cab mounted work light
                    • Canopy with FOPS ISO 10262 (Level 1) and Tip-Over Protection (TOPS) ISO 12117
                      • Coat hook
                        • Cup holder
                          • Control pattern changer (not available in Europe)
                            • Dozer blade with float function
                              • Floor mat
                                • Foot travel pedals
                                  • Gauges or indicators for fuel level engine coolant temperature, hour meter, engine oil pressure, air cleaner, alternator and glow plugs, service interval
                                    • Horn
                                      • Hydraulic oil cooler
                                        • Lifting eye on bucket linkage (optional in Europe)
                                          • Lockable storage box
                                            • Low maintenance linkage pin joints
                                              • Maintenance free battery
                                                • Rubber track
                                                  • Seatbelt, 76 mm (3 in) wide, retractable (optional in Europe)
                                                    • Standard stick
                                                      • Suspension seat, vinyl covered
                                                        • "Thumb ready" stick (standard equipment in all regions except Europe)
                                                          • Travel alarm (optional in Europe)
                                                            • Air conditioning
                                                              • Angle dozer blade with float function
                                                                • Beacon socket for canopy machines
                                                                  • Boom check valve (Europe only)
                                                                    • Boom mounted light
                                                                      • Cab, radio ready with FOPS ISO 10262 (Level 1), Tip-Over Protection (TOPS) ISO 12117, heater/defroster, interior light and windshield wiper/washer
                                                                        • Ecology drain valve for hydraulic tank
                                                                          • Ecology drain valve for engine oil
                                                                            • Fan and sun blind installation
                                                                              • Front screen guard for cab and canopy
                                                                                • High back suspension seat, fabric covered
                                                                                  • Hydraulic quick coupler lines
                                                                                    • Long stick
                                                                                      • Mechanical quick coupler
                                                                                        • Mirrors for cab and canopy
                                                                                          • Secondary auxiliary hydraulic lines

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