304 Mini Excavator



Technical Specifications
Benefits and Features
360 View

The Cat® 304 Mini Excavator delivers power and performance in a compact size to help you work in a wide range of applications.

Net Power 45 HP
Engine Model C1.7 Turbo
Gross Power - 2,400 rpm - SAE J1995:2014 48.4 HP
Bore 3.3 in
Emissions Meets U.S. EPA Tier 4 Final and EU Stage V emission standards.
Stroke 3.9 in
Displacement 101 in³
Net Power - 2,400 rpm - ISO 9249, 80/1269/EEC 45 HP
Note Net power advertised is the power available at the flywheel when the engine is at rated speed and rated power when the engine is installed with the factory configured fan, air intake system, exhaust system, and alternator with a minimum alternator load.
Operating Weight 9867 lb
Minimum Operating Weight with Canopy* 8655 lb
Maximum Operating Weight with Canopy** 9647 lb
Note (2) **Maximum Weight is based on steel tracks, operator, full fuel tank, long stick, straight blade, extra counterweight and no bucket.
Note (1) *Minimum Weight is based on rubber tracks, operator, full fuel tank, standard stick, straight blade, no bucket and no extra counterweight.
Maximum Operating Weight with Cab** 9867 lb
Minimum Operating Weight with Cab* 8875 lb
Dimensions - Long Stick
Dig Depth 138.2 in
Maximum Blade Depth 18.7 in
O/A Shipping Height 100 in
Maximum Dump Clearance 147.2 in
Stick Length 66.7 in
Maximum Dig Height 201.8 in
Maximum Reach - Ground Level 214.4 in
Track Width 66.9 in
Tail Swing with Counterweight 51.2 in
Swing Bearing - Height 21.9 in
Boom Height - Shipping Position 75.2 in
Boom Swing - Left 20.9 in
Maximum Reach 219.3 in
Boom In Reach 92.1 in
Boom Swing - Right 28.7 in
Track Belt/Shoe Width 13.8 in
Vertical Wall 99.8 in
Maximum Blade Height 16.5 in
Note *Overall Shipping Length depends on blade position during shipment.
Overall Shipping Length* 194.9 in
Ground Clearance 12 in
O/A Undercarriage Length 87 in
Tail Swing without Counterweight 47.4 in
Weight Increase from Minimum Configuration
Steel Tracks 430 lb
Counterweight 496 lb
Angle Blade 243 lb
Long Stick 66 lb
Travel System
Ground Pressure - Minimum Weight 4.2 psi
Maximum Traction Force - Low Speed 7329 lbf
Travel Speed - Low 2.2 mile/h
Ground Pressure - Maximum Weight 4.9 psi
Travel Speed - High 3.2 mile/h
Maximum Traction Force - High Speed 4271 lbf
Gradeability - Maximum 30 degrees
Service Refill Capacities
Cooling System 2.9 gal (US)
Engine Oil 1.6 gal (US)
Hydraulic System 17 gal (US)
Fuel Tank 17 gal (US)
Hydraulic Tank 14 gal (US)
Hydraulic System
Operating Pressure - Travel 3553 psi
Auxiliary Circuit - Secondary - Pressure 3553 psi
Digging Force - Stick - Long 4316 lbf
Auxiliary Circuit - Secondary - Flow 7 gal/min
Pump Flow at 2,400 rpm 25 gal/min
Operating Pressure - Swing 2611 psi
Auxiliary Circuit - Primary - Flow 21 gal/min
Auxiliary Circuit - Primary - Pressure 3553 psi
Note Flow and pressure are not combinable. Under load, as flow rises pressure goes down.
Type Load Sensing Hydraulics with Variable Displacement Piston Pump
Digging Force - Stick - Standard 4721 lbf
Digging Force - Bucket 8588 lbf
Operating Pressure - Equipment 3553 psi
Swing System
Boom Swing - Right 50 Degrees
Machine Swing Speed 9 r/min
Boom Swing - Left 78 Degrees
Angle Blade Height 14.2 in
Straight Blade Height 14.2 in
Straight Blade Width 66.9 in
Angle Blade Width 66.9 in
Angle Blade - Right 25 Degrees
Angle Blade - Left 25 Degrees
Certification - Cab and Canopy
Roll Over Protective Structure (ROPS) ISO 12117-2:2008
Top Guard ISO 10262:1998 (Level I)
Tip Over Protective Structure (TOPS) ISO 12117:1997
Average Exterior Sound Pressure (ISO 6395:2008) 97 dB(A)
Operator Sound Pressure (ISO 6396:2008) 76 dB(A)
Note European Union Directive “2000/14/EC”
Dimensions - Standard Stick
Maximum Reach - Ground Level 204.7 in
Vertical Wall 94.3 in
Note *Overall Shipping Length depends on blade position during shipment.
Tail Swing with Counterweight 51.2 in
Boom In Reach 88.8 in
Dig Depth 126.4 in
Maximum Dig Height 198.4 in
Maximum Blade Height 16.5 in
Swing Bearing - Height 21.9 in
Boom Swing - Left 20.9 in
Stick Length 54.9 in
O/A Undercarriage Length 87 in
Track Belt/Shoe Width 13.8 in
Boom Height - Shipping Position 63.8 in
Boom Swing - Right 28.7 in
Maximum Dump Clearance 143.5 in
Ground Clearance 12 in
Maximum Reach 209.8 in
O/A Shipping Height 100 in
Tail Swing without Counterweight 47.4 in
Maximum Blade Depth 18.7 in
Overall Shipping Length* 194.9 in
Recyclability 96%


  • Choose either a canopy (not available in some regions) or a sealed and pressurized cab which can be equipped with air conditioning, adjustable wrist rests, and a suspension seat to help keep you working comfortably all day long.


  • Controls are easy to use and the intuitive Next Generation LCD monitor provides easy to read machine information. An advanced touchscreen monitor can also be equipped as an upgrade option.


  • Moving around the job site is even easier with the Cat Stick Steer option. Easily switch from traditional travel controls with levers and pedals to joystick controls to move the machine and to operate the blade. The benefit of less effort and improved control is in your hands!


  • Strong lift and dig performance helps you get the job done faster. The reduced radius tail swing design provides exceptional stability and performance. With a maximum width of 1700 mm (67 in), the 304 can access those hard to get into areas. Dozer float allows for easy clean up. An angle blade is also an option for finished grading and easier backfilling applications.


  • Your safety is our top priority. The Cat mini excavator is designed to help keep you safe on the job. Courtesy work lights and a fluorescent retractable seat belt are just a couple of the safety features we’ve built into the machine.


  • Maintenance is quick and easy on the Cat mini excavator. Routine check points are easy to access at ground level through the side doors.


  • Equipped with features such as auto idle, auto engine shutdown, and efficient hydraulics with a variable displacement pump, the Cat mini excavator was designed with reducing your operating costs in mind.


  • The Cat® C1.7 engine meets U.S. EPA Tier 4 Final, EU Stage V, and Japan 2014 emission standards.
  • Cat diesel engines are required to use ULSD (ultra-low sulfur diesel fuel with 15 ppm of sulfur or less) or ULSD blended with the following lower-carbon intensity fuels up to: 20% biodiesel FAME (fatty acid methyl ester) * or 100% renewable diesel, HVO (hydrotreated vegetable oil) and GTL (gas-to-liquid) fuels. Refer to guidelines for successful application. Please consult your Cat dealer or “Caterpillar Machine Fluids Recommendations” (SEBU6250) for details.
  • Auto Idle helps reduce unnecessary fuel burn and greenhouse gas emissions by allowing the engine to automatically go into idle mode when the machine is not working.
  • Engine Idle Shutdown Timer reduces fuel burn, greenhouse gas emissions and unnecessary idle time by shutting down the machine after a pre-set idling period.
  • Cruise control helps you maintain a constant speed as you travel across your jobsite saving fuel and reducing greenhouse gas emissions.
  • The Cat® Seat Belt Reminder provides audible and visual warnings to remind operators to buckle up during machine operation. The easy-to-install system is compatible with all equipment brands to help ensure operator safety.
  • Extended maintenance intervals not only reduce downtime but decrease the amount of fluid and filters that are replaced over the life of the machine.
  • Remote Flash minimizes downtime and maintenance time while keeping your asset running with maximum efficiency. Alerts for machine updates are sent virtually from your Cat dealer and updates can be deployed without a dealer technician needing to be onsite.(if equipped)
  • Remote Troubleshoot decreases maintenance time and keeps your machine running with maximum efficiency by allowing your Cat dealer to virtually test the machine while working. Once a problem is identified, a technician can fix it the first time, saving time and money.(if equipped)
  • Cat Grade with advanced 2D and 3D technologies combine advanced guidance with optional automated machine control helping you reach grading targets while reducing fuel burn and greenhouse gas emissions by improving efficiency, job site productivity, and accuracy. (if equipped).

*Engines with no aftertreatment devices can use higher blends, up to 100% biodiesel. (for use of blends higher than 20% biodiesel, consult your Cat dealer)

Standard Equipment:

  • Engine
    • Cat® C1.7 Turbo Engine (U.S. EPA Tier 4 Final/EU Stage V)
    • Automatic Engine Idle
    • Automatic Engine Shutdown
    • Automatic Two Speed Travel
    • Fuel Water Separator
    • Power on Demand (not available in all regions)
    • Variable Displacement Piston Pump
    • Load Sensing/Flow Sharing Hydraulics
  • Hydraulics
    • Smart Tech Electronic Pump
    • Accumulator
    • Automatic Swing Brake
    • Auxiliary Hydraulic Lines
    • One and Two Way Auxiliary Flow
    • Continuous Auxiliary Flow
    • Auxiliary Line Quick Disconnects
  • Operator Environment
    • Canopy or Cab (Canopy not available in some regions)
    • Top Guard ISO 10262:1998 Level I
    • ROPS – ISO 12117-2:2008
    • TOPS – ISO 12117:1997
    • Stick Steer Mode
    • Travel Cruise Control
    • Control Pattern Changer (optional in some regions)
    • Adjustable Wrist Rests
    • Washable Floor Mat
    • Travel Pedals and Hand Levers
    • Machine Security – Standard Key with Pass Code
    • Fabric Suspension Seat (Cab only)
    • Vinyl Suspension Seat (Canopy only)
    • Hydraulic Lockout – All Controls
    • Retractable High Visibility Seat Belt (75 mm/3 in)
    • Coat Hook
    • Cup Holder
    • Storage Pocket
    • Skylight
    • Mounting Bosses for Front
    • Signaling/Warning Horn
    • Interior Light (Cab only)
    • Boom Light, Halogen (not available in all regions)
    • Utility Space for Mobile Phone
    • Next Generation Color LCD Monitor (IP66)
      – Fuel Level and Coolant Temperature Gauges
      – Maintenance and Machine Monitoring
      – Performance and Machine Adjustments
      – Numeric Security Code
      – Multiple Languages
      – Hour Meter with Wake Up Switch
      – Jog Dial (cab only)
  • Undercarriage
    • Rubber Belt (350 mm/13.8 in)
    • Dozer Straight Blade
    • Dozer Blade Float
    • Tie Downs on Track Frame
  • Boom, Stick And Linkages
    • One Piece Boom (2500 mm/98.4 in)
    • Standard Stick (1395 mm/54.9 in)
    • Front Shovel Capable – Pin-On
    • Thumb Ready
    • Certified Lifting Eye
  • Electrical
    • 12 Volt Battery
    • Software (machine and monitor)
    • Maintenance Free Battery
    • Battery Disconnect
    • 12 Volt Power Socket
    • Travel Alarm (optional in some regions)
  • Other
    • Counterweight (225 kg/496 lb)

Optional Equipment:

  • Operator Environment
    • Cab with Air Conditioning
    • Cab with Heater
    • No Travel Pedals and Hand Levers (optional in some regions)
    • Machine Security – Push to Start with Key Fob/Pass Code
    • LED Front Lights
    • LED Front and Rear Lights
    • LED Boom Light
    • Mirrors, Left, Right and Rear
    • Camera
    • Radio – Bluetooth®, Auxiliary, Microphone, USB (charging only) (Cab only)
    • Next Generation Advanced Monitor
      – Touch Screen
      – Site Reference System
      – High Definition Camera Capable (IP68 and IP69K)
      – Numeric Security Code
  • Undercarriage
    • Steel Track (350 mm/13.8 in)
    • Steel Track with Rubber Pads
    • Angle Blade
  • Boom, Stick And Linkages
    • Long Stick (1695 mm/66.7 in)
    • Front Shovel Capable – Dual Lock Manual Coupler
    • Front Shovel Capable – Hydraulic Coupler
    • Attachments including Couplers, Thumbs, Buckets, Augers and Hammers
    • 2nd Auxiliary Hydraulic Lines
    • Bucket Divert Lines
    • Boom Lowering Check Valve
    • Stick Lowering Check Valve
    • Hydraulic Quick Coupler Lines
  • Electrical
    • Product Link PL243 (regulations apply)
    • Product Link PLE643 (regulations apply)
  • Guarding
    • Polycarbonate Half Height Front Guard (Canopy only)
    • Polycarbonate Front Guard (ISO 10262:1998 Level I and EN356 P5A)
    • Heavy Duty Front Guard ISO 10262:1998 Level II
    • Heavy Duty Top Guard 10262:1998 Level II (Cab only)
  • Other
    • Bio Oil Capable
    • Eco Drain
    • Water Jacket Heater

Related Equipment