Case CX31 Mini Excavator

Description:

The Case CX31 Mini Excavator delivers robust performance in a compact footprint, ideal for contractors working in tight areas like urban construction sites or residential jobs. With strong hydraulic output and a smooth control layout, the CX31 is known for its durability and efficient operation.

Engine & Performance:

• Engine: Yanmar 3TNV88-B diesel

• Net Power: 28.4 hp (21.2 kW)

• Displacement: 1.642 L (100.2 cu in)

• Fuel Capacity: 11.1 gal (42 L)

Hydraulics:

• Hydraulic Flow (Main): 14.5 + 14.5 GPM (55 + 55 L/min)

• Relief Pressure: 3,133 psi (216 bar)

• System Type: Variable displacement axial piston pumps

• Control: Pilot-operated joystick system for smooth digging

Travel & Swing:

• Travel Speeds: 1.3 mph (low), 2.7 mph (high)

• Swing Speed: 9.1 rpm

Key Dimensions & Specs:

• Operating Weight: 7,110 lbs (3,226 kg)

• Max Digging Depth: 9 ft 6 in (2.9 m)

• Max Reach at Ground Level: 16 ft 2 in (4.93 m)

• Bucket Digging Force: 6,603 lbf (29.4 kN)

Maintenance Highlights:

• Service Points: Engine oil, fuel filter, hydraulic fluid reservoir, track rollers

• Frequently Replaced Parts: Boom cylinder seals, control valve O-rings, idlers, track tensioners

• Hydraulic cylinder repair kits for CX31

• Case CX31 final drive motors

• Undercarriage parts, including tracks and sprockets

Common Issues & Quick Fixes:

• Hydraulic fluid leaks: Usually at the cylinder rod ends — install new seal kits

• Track tension issues: Often from idler spring fatigue — adjust or replace tensioner

• Boom drift: Common with worn control valves — reseal or replace valve cartridge

Pro Tips:

• Regularly inspect pivot points for wear and lubricate to prevent pin damage

• Use factory-matched bushings and pins to maintain proper arm movement

• Keep air filters clean to preserve engine efficiency

Serial Number Info:

• Serial number plate is typically found on the frame behind the operator station or near the left track

• CX31 serials begin with NAB031 series