Caterpillarexcavator

Caterpillar E120B

Maintenance schedule, common problems & OEM parts breakdown

The Caterpillar E120B is a mid-sized hydraulic excavator belonging to the E Series lineup, manufactured during the 1990s. This machine features a Caterpillar 3114 engine delivering 84 hp (62.7 kW) and an operating weight range of approximately 11 to 13 metric tons (24,250 to 28,664 lb). It is configured with various boom and stick options, including a 2100 mm (6'11") stick, a 2500 mm (8'2") stick, and a 3000 mm (9'10") stick, allowing for diverse digging depths up to 6050 mm (19.85 ft) depending on the setup.

Across its production, the E120B maintained a reputation for balancing power with maneuverability, making it a staple for residential construction and utility work. In today's used equipment market, this model remains highly relevant due to its durable 3114 engine and predictable hydraulic performance. Its presence in the secondary market is driven by the demand for reliable, mid-sized machines that are cost-effective to transport and capable of performing light to medium-duty excavation, trenching, and foundation tasks.

Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.

Caterpillar E120B specifications

Engine

Model	3114
Gross Power	84 hp (62.7 kW)
Displacement	268.6 cu in (4.4 L)

Weights

Operating Weight	12,800 kg (28,219.2 lb) — varies by configuration/series
Ground Pressure	5.97 psi (41.17 kPa)

Dimensions

Width to Outside of Tracks	2,490 mm (8.17 ft)
Height to Top of Cab	2,700 mm (8.86 ft)
Ground Clearance	460 mm (1.51 ft)
Tail Swing Radius	2,115 mm (6.94 ft)
Length of Track on Ground	2,780 mm (9.13 ft)
Removal Counterweight Clearance	920 mm (3.02 ft)
Track Gauge	1,990 mm (6.53 ft)
Track Shoe Width	500 mm (19.69 in)

Performance

Max Digging Depth	Varies by configuration: 5,150 mm (16.9 ft) to 6,050 mm (19.85 ft)
Max Reach at Ground	Varies by configuration: 7,925 mm (26.01 ft) to 8,740 mm (28.68 ft)
Max Loading Height	Varies by configuration: 5,845 mm (19.18 ft) to 6,330 mm (20.77 ft)
Max Cutting Height	Varies by configuration: 8,215 mm (26.96 ft) to 8,695 mm (28.53 ft)
Max Vertical Wall Digging Depth	Varies by configuration: 4,515 mm (14.82 ft) to 5,340 mm (17.52 ft)
Swing Speed	Not documented for this exact serial range — verify with your dealer
Max Travel Speed	5 km/h (3.11 mph)
Drawbar Pull	96 kN (21,581.66 lb)

Forces

Hydraulic System Relief Valve Pressure	29,440.6 kPa (4,270 psi)
Hydraulic Pump Flow Capacity	236 L/min (62.4 gal/min)

Service capacities (summary)

Fuel Tank Capacity	250 L (66.1 gal)
Hydraulic System Fluid Capacity	165 L (43.6 gal)

Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.

E120B fluids & capacities

System	Capacity	Recommended fluid
Fuel tank	250 L (66.1 gal)	Not specified
Hydraulic system total AND hydraulic tank	165 L (43.6 gal) to 165 L (44 gal)	Not specified

Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.

Caterpillar E120B maintenance schedule

Service interval	Tasks
Every 10 h	Check engine oil level and condition Inspect hydraulic fluid level via sight glass Verify coolant level and cap integrity Drain water from fuel/water separator Check air filter restriction indicator Inspect pins, bushings, and attachment points for wear
Every 250 h	Change engine oil and filter Grease all boom, stick, bucket, and swing points Drain fuel water separator Perform visual inspection of belts and hoses Check air filter primary element
Every 500 h	Replace fuel filter Replace hydraulic return filter Perform battery service and terminal inspection Conduct detailed undercarriage inspection Test coolant additive/SCA levels
Every 1,000 h	Perform hydraulic oil sample analysis (S.O.S) Service final drive oil Inspect turbocharger for defects Check ROPS bolt torque Measure undercarriage wear components
Every 2,000 h	Change hydraulic system oil Perform coolant flush and replacement Conduct comprehensive structural inspection of boom and stick welds Evaluate major machine components Replace worn belts and hoses

Servicing the E120B beyond the schedule

Predictive Maintenance & Fluid Analysis

Utilize Caterpillar S.O.S services to monitor the 3114 engine oil and hydraulic fluid for wear metals like iron or copper. Regular sampling during 1000-hour and 2000-hour intervals detects early signs of pump or bearing degradation. Monitor coolant pH and SCA levels to prevent internal liner pitting. Analyzing hydraulic particle counts ensures the system maintains required cleanliness, preventing catastrophic valve or cylinder failure.

Corrective & Common Repairs

Monitor hydraulic hoses for cracks, abrasion, or leaks to prevent sudden pressure loss. Inspect pins and bushings regularly; excessive play in attachment points often requires replacement to maintain digging precision. Watch for air filter restriction indicators to prevent engine power loss. If hydraulic relief valve pressure deviates from 29440.6 kPa (4270 psi), inspect the system for contamination or component fatigue.

Overhaul & Rebuild Points

Plan for major structural inspections of boom and stick welds during 2000-hour service tiers. Evaluate turbocharger condition and replace if significant play is detected. Significant undercarriage wear measured at 1000-hour intervals may necessitate sprocket or track shoe replacement. When hydraulic oil becomes heavily oxidized, a full system flush and filter replacement are required to protect the pump and control valves.

Seasonal & Environment Servicing

In dusty or quarry environments, check air filters daily and clean radiator/oil cooler fins frequently to prevent overheating. For machines operating in high-moisture areas, prioritize fuel water separator draining and battery terminal inspections. During cold weather operations, ensure hydraulic fluid viscosity is appropriate and inspect all grease points for dried lubricant that could impede movement.

E120B fault codes & troubleshooting

Code	Meaning	Likely cause	What to do
110-0	Engine Coolant Temperature — Above Normal	Low coolant level or thermostat failure	Inspect cooling system and refill coolant
110-3	Engine Coolant Temp Sensor — Voltage High	Open circuit or sensor failure	Check wiring and replace sensor if faulty
41-3	8-Volt DC Supply — Voltage Above Normal	Short to power on 8V reference circuit	Inspect sensors sharing the 8V supply and isolate fault
41-4	8-Volt DC Supply — Voltage Below Normal	Short to ground on 8V reference circuit	Disconnect sensors one at a time to locate short
174-3	Engine Fuel Temperature — Voltage Above Normal	Open circuit in sensor wiring	Inspect harness and replace sensor if necessary
190-8	Engine Speed — Abnormal Frequency	Speed sensor air gap, sensor failure, or tone ring damage	Check sensor gap and test speed sensor/tone ring

Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.

E120B attachments & work tools

Buckets

Available in widths such as 18 inch (457.2 mm), 24 inch (609.6 mm), and 60 inch (1524 mm) ditch buckets. Configurations include digging, ditching, and cutting edge attachments, compatible with pin-on or coupler mounting.

Hydraulic hammers

Compatible breaker class includes models weighing approximately 3365.00 lb (1526.24 kg). These units are available with autogreaser features.

Quick couplers

The machine supports coupler attachments for efficient tool changes. Specific S-type coupling elements are also documented for this class.

Thumbs/grapples

Thumb kits are available for the E120B to improve material handling capabilities.

Rippers

Ripper attachments are compatible with the E120B for specialized ground penetration tasks.

Hydraulic-kit notes

The system features a hydraulic pump flow capacity of 62.4 gal/min (236 lpm) and a relief valve pressure of 4270 psi. Hydraulic kits are available for specific attachment integration.

All E120B assemblies by section

Every catalogued assembly group for the Caterpillar E120B. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Engine

Accessory

Alternator (24v-30a)

Camshaft

Cooling System - Part 2 Of 2

Cooling System Part 1 Of 2

Crank Case - Part 1 Of 2

Crank Case - Part 2 Of 2

Crankshaft And Flywheel

Cylinder Head

Electric Parts

Flywheel Housing

Fuel Feed Pump

Fuel Filter

Fuel System - Part 2 Of 2

Fuel System Part 1 Of 2

Governor - Part 3 Of 4

Governor - Part 1 Of 4

Governor - Part 4 Of 4

Governor - Part 2 Of 4

Injection Pump - Part 5 Of 5

Injection Pump - Part 4 Of 5

Injection Pump Part 1 Of 5

Injection Pump - Part 2 Of 5

Injection Pump - Part 3 Of 5

Inlet And Exhaust System Part 1 Of 2

Inlet And Exhaust System - Part 2 Of 2

Muffler

Nozzle

Oil Cooler

Oil Filter

Oil Pan

Oil Pipe

Oil Pipe (For Turbo-Charger)

Overhaul Gasket Kit - Part 1 Of 2

08***69	Washer	8
08***12	Gasket	1
09***49	Gasket, Air Heater	1
09***72	O-Ring, Breather	2

See all parts with full part numbers in Heavy Parts AI →

Overhaul Gasket Kit - Part 2 Of 2

09***18	Seal	8
09***27	Seal	1
09***42	Oil Seal Assembly.	1
09***19	Seal	2

See all parts with full part numbers in Heavy Parts AI →

Oversize And Undersize Parts

1R***34	Piston	4
1R***35	Piston Ring Set	4
1R***36	Piston Ring Set	4
1R***67	Piston	4

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Piston And Connecting Rod

Rocker Cover

Starter (24v-5kw) - Part 1 Of 2

Starter (24v-5kw) - Part 2 Of 2

Timing Gear

Timing Gear Case - Part 2 Of 2

Timing Gear Case - Part 1 Of 2

Turbo-Charger

Valve Mechanism - Part 2 Of 2

Valve Mechanism - Part 1 Of 2

Water Pump

Vehicle

Accumulator (7nf1-00629)

Air Cleaner

Air Conditioner Part 1 Of 4

Air Conditioner - Part 4 Of 4

Air Conditioner Part 2 Of 4

Air Conditioner Part 3 Of 4

Air Conditioner Centrifugal Fan - Part 2 Of 2

Air Conditioner Centrifugal Fan - Part 1 Of 2

Air Conditioner Compressor And Clutch Part 2 Of 3

Air Conditioner Compressor And Clutch-Part 3 Of 3

Air Conditioner Compressor And Clutch Part 1 Of 3

Air Conditioner Duct And Control-Part 2 Of 2

Air Conditioner Duct And Control Part 1 Of 2

Air Conditioner Lines Part 1 Of 4

Air Conditioner Lines Part 3 Of 4

Air Conditioner Lines Part 2 Of 4

Air Conditioner Lines-Part 4 Of 4

Backhoe Bucket - 0.35 Cubic Meter - Part 2 Of 2

Backhoe Bucket - 0.55 Cubic Meters Part 1 Of 2

Backhoe Bucket - 0.50 Cubic Meters - Part 1 Of 2

Backhoe Bucket - 0.45 Cubic Meters - Part 2 Of 2

Backhoe Bucket - 0.35 Cubic Meter Part 1 Of 2

Backhoe Bucket - 0.30 Cubic Meter - Part 2 Of 2

Backhoe Bucket - 0.55 Cubic Meters - Part 2 Of 2

Backhoe Bucket - 0.60 Cubic Meters - Part 2 Of 2

Backhoe Bucket - 0.20 Cubic Meter Part 1 Of 2

Backhoe Bucket - 0.50 Cubic Meters - Part 2 Of 2

Backhoe Bucket - 0.20 Cubic Meter - Part 2 Of 2

Backhoe Bucket - 0.60 Cubic Meter Part 1 Of 2

Backhoe Bucket - 0.45 Cubic Meters - Part 1 Of 2

Backhoe Bucket - 0.30 Cubic Meter Part 1 Of 2

Bank Forming Bucket

Base Frame

Battery Cover

Boom Cylinder Part 1 Of 3

Boom Cylinder-Part 3 Of 3

Boom Cylinder Part 2 Of 3

Boom Lights

Boom Line Group

Boom Lines Part 2 Of 2

Boom Lines

Boom Lines Part 1 Of 2

Boom Support (Boom Line Group)

Boom Support

Bucket Cylinder-Part 2 Of 2

Bucket Cylinder Part 1 Of 2

Bucket Linkage - Part 1 Of 2

Bucket Linkage - Part 2 Of 2

Backhoe Bucket - 0.40 Cubic Meters - Part 2 Of 2

Backhoe Bucket - 0.40 Cubic Meters Part 1 Of 2

Cab (Frame) Part 1a Of 7 (7nf1-01789)

Cab (Door And Window Frame) (For Working Light) Part 2b Of 5 (7nf01790-)

Cab (Frame) (For Working Light) Part 1a Of 7 (7nf1-01789)

Cab (Glass And Corner Rubber) (For Working Light) Part 3a Of 7 (7nf1-01789)

Cab (Interior Parts) (For Working Light) Part 4 Of 7 (7nf1-01789)

Cab (Glass And Corner Rubber) Part 3 Of 7 (7nf1-01789)

Cab (Frame) (For Working Light) Part 1a Of 5 (7nf01790-)

Cab (Frame) (For Working Light) Part 1b Of 7 (7nf1-01789)

Cab (Glass And Corner Rubber) Part 3a Of 7 (7nf1-01789)

Cab (Door And Window Frame) (For Working Light) Part 2c Of 5 (7nf01790-)

Cab (Interior Parts) Part 4a Of 7 (7nf1-01789)

Cab (Frame) Part 1d Of 7 (7nf1-01789)

Cab (Door And Window Frame) (For Working Light) Part 2 Of 7 (7nf1-01789)

Cab (Glass And Corner Rubber) (For Working Light) Part 3 Of 5 (7nf01790-)

Cab (Door And Window Frame) (For Working Light) Part 2b Of 7 (7nf1-01789)

Cab (Frame) (For Working Light) Part 1d Of 5 (7nf01790-)

Cab (Door And Window Frame) Part 2c Of 7 (7nf1-01789)

Cab (Frame) (For Working Light) Part 1c Of 5 (7nf01790-)

Cab (Interior Parts) Part 4 Of 7 (7nf1-01789)

Cab (Door And Window Frame) Part 2 Of 7 (7nf1-01789)

Cab (Back Mirror) (For Working Light) Part 7 Of 7 (7nf1-01789)

Cab (Door And Window Frame) (For Working Light) Part 2a Of 5 (7nf01790-)

Cab (Interior Parts) (For Working Light) Part 4 Of 5 (7nf01790-)

Cab (Glass Holder) Part 5 Of 7 (7nf1-01789)

Cab (Door And Window Frame) Part 2b Of 7 (7nf1-01789)

Cab (Frame) Part 1 Of 7 (7nf1-01789)

Cab (Door And Window Frame) (For Working Light) Part 2 Of 5 (7nf01790-)

Cab (Window Washer) (For Working Light) Part 6 Of 7 (7nf1-01789)

Cab (Frame) (For Working Light) Part 1 Of 5 (7nf01790-)

Cab (Glass And Corner Rubber) (For Working Light) Part 3 Of 7 (7nf1-01789)

Cab (Door And Window Frame) (For Working Light) Part 2a Of 7 (7nf1-01789)

Cab (Window Washer) Part 6 Of 7 (7nf1-01789)

Cab (Frame) (For Working Light) Part 1c Of 7 (7nf1-01789)

Cab (Frame) (For Working Light) Part 1b Of 5 (7nf01790-)

Cab (Frame) (For Working Light) Part 1 Of 7 (7nf1-01789)

Cab (Back Mirror) Part 7 Of 7 (7nf1-01789)

Cab (Frame) Part 1b Of 7 (7nf1-01789)

Cab (Window Washer) (For Working Light) Part 5 Of 5 (7nf01790-)

Cab (Door And Window Frame) Part 2a Of 7 (7nf1-01789)

Cab (Glass Holder) (For Working Light) Part 5 Of 7 (7nf1-01789)

Cab (Frame) Part 1c Of 7 (7nf1-01789)

Cab (Interior Parts) (For Working Light) Part 4a Of 5 (7nf01790-)

Cab (Door And Window Frame) (For Working Light) Part 2d Of 5 (7nf01790-)

Cab (Interior Parts) Part 4 Of 5 (7nf01790-)

Cab (Door And Window Frame) Part 2a Of 5 (7nf01790-)

Cab (Frame) Part 1b Of 5 (7nf01790-)

Cab (Frame) Part 1a Of 5 (7nf01790-)

Cab (Frame) Part 1d Of 5 (7nf01790-)

Cab (Glass And Corner Rubber) Part 3 Of 5 (7nf01790-)

Cab (Door And Window Frame) Part 2d Of 5 (7nf01790-)

Cab (Door And Window Frame) Part 2 Of 5 (7nf01790-)

Cab (Interior Parts) Part 4a Of 5 (7nf01790-)

Cab (Door And Window Frame) Part 2b Of 5 (7nf01790-)

Cab (Door And Window Frame) Part 2c Of 5 (7nf01790-)

Cab (Window Washer) Part 5 Of 5 (7nf01790-)

Cab (Frame) Part 1 Of 5 (7nf01790-)

Cab (Frame) Part 1c Of 5 (7nf01790-)

Carrier Roller

Check Valve (For 2 Pumps Flow Cofluence Hyd. Line Group)

Clamshell - 0.26 Cubic Meter Part 2 Of 4 (For Telescopic Stick)

Clamshell - 0.26 Cubic Meter Part 1 Of 4 (For Telescopic Stick)

Clamshell - 0.26 Cubic Meters Part 4 Of 4 (For Telescopic Stick)

Clamshell - 0.26 Cubic Meters Part 3 Of 4 (For Telescopic Stick)

Clamshell Cylinder Part 2 Of 2 (For Telescopic Stick)

Clamshell Cylinder (For Telescopic Stick) Part 1 Of 2

Control Pattern Quick Changer

Control Valve Part 5 Of 6

Control Valve Part 1 Of 6

Control Valve-Part 6 Of 6

Control Valve Part 4 Of 6

Control Valve Part 3 Of 6

Control Valve Part 2 Of 6

Controller Part 1 Of 2

Controller - Part 2 Of 2

Controls

Counterweight (For Telescopic Stick)

Defroster (7nf-D88.09)

Defroster (7nf D88.10-)

Delivery Lines

Ditch Cleaning Bucket - 0.50 Cubic Meter

Drain Lines-Part 2 Of 2

Drain Lines Part 1 Of 2

Electric Parts

Electric Parts (For Cold Weather Starting Kit) (7nf00126-)

Electric Parts (For Travel Alarm)

Engine - Part 2a Of 2

Engine - (For Cold Weather Starting Kit)

Engine - Part 1 Of 2

Engine - Part 2 Of 2

Engine - (For 50a Alternator, Working Light)

Engine - Part 2b Of 2

Engine Control Part 2 Of 2 (7nf04358-)

Engine Control Part 2 Of 3 (7nf02516-04357)

Engine Control Part 1 Of 5 (7nf1-02515)

Engine Control Part 3 Of 5 (7nf1-02515)

Engine Control Part 2 Of 5 (7nf1-02515)

Engine Control Part 3 Of 3 (7nf02516-04357)

Engine Control Part 4 Of 5 (7nf1-02515)

Engine Control Part 5 Of 5 (7nf1-02515)

Engine Control Part 1 Of 3 (7nf02516-04357)

Engine Control Part 1 Of 2 (7nf04358-)

Engine Hood - Part 1 Of 2

Engine Hood - Part 2 Of 2

Front Lines (For One Piece Boom)

Front Lubrication Lines (For One Piece Boom)

Front Lubrication Lines (For Long Stick) (7nf03530-)

Fuel Lines (For Water Separator) (7nf04358-)

Fuel Tank And Fuel Lines - Part 2 Of 2

Fuel Tank And Fuel Lines - Part 1 Of 2

Grease Bath

Grease Gun Support (7nf04358-)

Handrail

Headrest

Heater (3000kcal/H) Part 1 Of 4 (7nf01790-)

Heater (3000kcal/H) Part 4 Of 4 (7nf01790-)

Heater (3000kcal/H) Part 1 Of 3 (7nf1-01789)

Heater (3000kcal/H) Part 2 Of 4 (7nf01790-)

Heater (3000kcal/H) Part 3 Of 3 (7nf1-01789)

Heater (3000kcal/H) Part 2 Of 3 (7nf1-01789)

Heater (3000kcal/H) Part 3 Of 4 (7nf01790-)

Hose Reel Part 2 Of 2 (For Telescopic Stick)

Hose Reel Part 1 Of 2 (For Telescopic Stick)

Hydraulic Tank - Part 2 Of 2

Hydraulic Tank Part 1 Of 2

Hydraulic Tank Part 1 Of 2 (For Cold Weather Starting Kit)

Hydraulic Tank Part 2 Of 2 (For Cold Weather Starting Kit)

Idler Wheel

Key

Leather Seat

Light, Boom Right

Long Stick - 3000mm

Long Stick Line Group - Side

Long Stick Line Group - Upper

Lower Structure Cover

Manifold-Part 3 Of 3

Manifold Part 1 Of 3

Manifold (For Automatic Swing Brake) Part 3 Of 3 (7nf01790-)

Manifold (For Automatic Swing Brake) Part 1 Of 3 (7nf01790-)

Manifold Part 2 Of 3

Manifold (For Automatic Swing Brake) Part 2 Of 3 (7nf01790-)

Medium Stick - 2500mm

Medium Stick Line Group - Upper

Medium Stick Line Group - Side

Nipper Part 1 Of 2

Nipper - Part 2 Of 2

Oil Mist Cover (7nf01230-04357)

One Piece Boom - Part 2 Of 2

One Piece Boom - Part 1 Of 2

Pilot Filter

Pump Part 6 Of 7

Pump Part 2 Of 7

Pump Part 4 Of 7

Pump Part 1 Of 7

Pump Part 3 Of 7

Pump Part 5 Of 7

Pump-Part 7 Of 7

Pump Drive

Pump Suction Lines

Radiator Part 2 Of 3

Radiator - Part 3 Of 3

Radiator Part 1 Of 3

Radio - Am

Radio Mantle

Reducing Valve Part 1 Of 2

Reducing Valve-Part 2 Of 2

Relief Valve

Relief Valve Part 2 Of 2

Relief Valve Part 1 Of 2

Remote Control Valve-Part 2 Of 2

Remote Control Valve Part 1 Of 2

Return Lines-Part 2 Of 2

Return Lines Part 1 Of 2

Rotary Joint

Safety Lock Valve

Seat And Floor Mat Part 2 Of 3

Seat And Floor Mat-Part 3 Of 3

Seat And Floor Mat Part 1 Of 3

Seat Belt

Selector Valve (For Control Pattern Quick Changer)

Servo And Pilot Lines - Part 1 Of 2 7nf00126-649, 651, 652, 654-665, 667-680, 682-712,

Servo And Pilot Lines - Part 2 Of 2 7nf00126-649, 651, 652, 654-665, 667-680, 682-712,

Servo And Pilot Lines - Part 2 Of 2 (7nf00650, 653, 666, 681, 713, 717, 718, 725, 726, 730, 731

Servo And Pilot Lines - Part 4 Of 5 (7nf01230-)

Servo And Pilot Lines - Part 1 Of 2 (7nf1-00125)

Servo And Pilot Lines - Part 2 Of 4 (7nf1-01229)

Servo And Pilot Lines - Part 5 Of 5 (7nf01230-)

Servo And Pilot Lines - Part 2 Of 5 (7nf01230-)

Servo And Pilot Lines - Part 1 Of 4 (7nf1-01229)

Servo And Pilot Lines - Part 3 Of 5 (7nf01230-)

Servo And Pilot Lines - Part 3 Of 4 (7nf1-01229)

Servo And Pilot Lines

Servo And Pilot Lines (For Travel Alarm)

Servo And Pilot Lines (For Automatic Swing Brake) (7nf01790-)

Servo And Pilot Lines - Part 1 Of 2 7nf00650, 653, 666, 681, 713, 717, 717, 718, 725, 726, 730, 731

Servo And Pilot Lines - Part 2 Of 2

Servo And Pilot Lines - Part 3 Of 3 (7nf00834-)

Servo And Pilot Lines - Part 2 Of 3 (7nf00834-)

Servo And Pilot Lines (For Automatic Swing Brake)

Servo And Pilot Lines - Part 1 Of 2

Servo And Pilot Lines - Part 2 Of 2 (7nf1-00125)

Servo And Pilot Lines - Part 4 Of 4 (7nf1-01229)

Servo And Pilot Lines - Part 1 Of 5 (7nf01230-)

Servo And Pilot Lines - Part 1 Of 3 (7nf00834-)

Shipping Plug

Shockless Valve

Short Stick - 2100mm

Short Stick Line Group - Side

Shuttle Valve (For 2 Pumps Flow Cofluence Hyd. Line Group)

Shuttle Valve (For Automatic Swing Brake) (7nf01790-)

Shuttle Valve (For Travel Alarm)

Single Ripper Tooth

Slow Return Valve

Slow Return Valve (For Telescopic Stick)

Solenoid Valve (For Automatic Swing Brake) (7nf1-01789)

Stick And Bucket Lines

Stick Cylinder Part 2 Of 3

Stick Cylinder Part 1 Of 3

Stick Cylinder-Part 3 Of 3

Stick Support (For Short Stick Line Group - Side)

Stick Support (For Medium Stick Line Group - Upper)

Stick Support (For Long Stick Line Group - Upper)

Stick Support (For Medium Stick Line Group - Side)

Stick Support (For Long Stick Line Group - Side)

Stop Valve

Suspension Seat Part 2 Of 3

Suspension Seat - Part 3 Of 3

Suspension Seat Part 1 Of 3

Swing Drive (For Automatic Swing Brake)

Swing Drive Part 1 Of 2

Swing Drive-Part 2 Of 2

Swing Frame And Counterweight Part 1 Of 4

Swing Frame And Counterweight - Part 2 Of 4

Swing Frame And Counterweight - Part 4 Of 4

Swing Frame And Counterweight - Part 3 Of 4

Swing Frame Cover - Side Part 2 Of 2 (7nf1-00128)

Swing Frame Cover - Side Part 1 Of 3 (7nf00129-)

Swing Frame Cover - Side Part 1 Of 2 (7nf1-00128)

Swing Frame Cover - Side Part 2 Of 3 (7nf00129-)

Swing Frame Cover - Side Part 3 Of 3 (7nf00129-)

Swing Frame Cover - Support

Swing Frame Cover - Under-Part 2 Of 2

Swing Frame Cover - Under Part 1 Of 2

Swing Frame Cover - Upper - Part 1 Of 2

Swing Frame Cover - Upper - Part 2 Of 2

Swing Frame Support

Swing Gear-Part 2 Of 2

Swing Gear Part 1 Of 2

Swing Lines

Swing Motor-Part 2 Of 2

Swing Motor Part 1 Of 2 (For Automatic Swing Brake)

Swing Motor Part 1 Of 2

Swing Motor Part 2 Of 2 (For Automatic Swing Brake)

Switch Box (Monitor Panel) Part 2a Of 3

Switch Box (Body) Part 3 Of 3

Switch Box (Panel) Part 1 Of 3

Switch Box (Monitor Panel) Part 2 Of 3

Switch Box (Body)-Part 3b Of 3

Switch Box (Body) Part 3a Of 3

Switch Box (Body) Part 3b Of 3

Switch Box (Panel) Part 1a Of 3

Switch Box (For Automatic Swing Brake)

Swivel Guard

Telescopic Stick - Part 3 Of 4

Telescopic Stick - Part 4 Of 4

Telescopic Stick - Part 2 Of 4

Telescopic Stick Part 1 Of 4

Telescopic Stick Cylinder-Part 2 Of 2

Telescopic Stick Cylinder Part 1 Of 2

Tension And Adjuster Cylinder-Part 2 Of 3

Tension And Adjuster Cylinder-Part 1 Of 3

Tension And Adjuster Cylinder-Part 3 Of 3

Tool Box

Tool Kit Part 1 Of 2

Tool Kit - Part 2 Of 2

Track - 770mm Apex Shoes

Track - 600mm Triple Grouser Shoes

Track - 500mm Triple Grouser Shoes

Track - 700mm Triple Grouser Shoes

Track - 770mm Triple Grouser Shoes

Track - 500mm Flat Shoes

Track Guard

Track Roller

Transfer Group (Plates And Labels) Japanese (For Breaker)

Transfer Group Part 2 Of 2 (Plates And Labels) Japanese - Cab

Transfer Group (Plates And Labels) Japanese - Body (7nf1-03310)

Transfer Group (Plates And Labels) Japanese - Body (7nf03311-)

Transfer Group (Plates And Labels) Japanese (For Telescopic Stick)

Transfer Group Part 1 Of 2 (Plates And Labels) Japanese - Cab

Transfer Group (Plates And Labels) Japanese (For Cold Weather Starting Kit)

Travel Brake Valve Part 2 Of 2 (7nf00126-)

Travel Brake Valve (7nf00126-) Part 1 Of 2

Travel Drive Part 3 Of 7 (7nf00126-00920)

Travel Drive Part 7 Of 7 (7nf00126-00920)

Travel Drive Part 6 Of 7 (7nf00921-04357)

Travel Drive Part 7 Of 7 (7nf00921-04357)

Travel Drive Part 2 Of 6 (7nf1-00125)

Travel Drive Part 3 Of 5 (7nf04358-)

Travel Drive Part 6 Of 6 (7nf1-00125)

Travel Drive Part 6 Of 7 (7nf00126-00920)

Travel Drive Part 4 Of 7 (7nf00921-04357)

Travel Drive Part 5 Of 6 (7nf1-00125)

Travel Drive Part 5 Of 7 (7nf00126-00920)

Travel Drive Part 2 Of 7 (7nf00921-04357)

Travel Drive Part 1 Of 7 (7nf00921-04357)

Travel Drive Part 2 Of 7 (7nf00126-00920)

Travel Drive Part 3 Of 6 (7nf1-00125)

Travel Drive Part 4 Of 5 (7nf04358-)

Travel Drive Part 1 Of 7 (7nf00126-00920)

Travel Drive Part 1 Of 5 (7nf04358-)

Travel Drive Part 3 Of 7 (7nf00921-04357)

Travel Drive Part 4 Of 7 (7nf00126-00920)

Travel Drive Part 1 Of 6 (7nf1-00125)

Travel Drive Part 5 Of 7 (7nf00921-04357)

Travel Drive Part 2 Of 5 (7nf04358-)

Travel Drive Part 4 Of 6 (7nf1-00125)

Travel Drive Part 5 Of 5 (7nf04358-)

Travel Drive And Sprocket

Travel Lines

Travel Motor Lines (7nf04358-) Part 2 Of 2

Travel Motor Lines (7nf1-04357) - Part 1 Of 2

Travel Motor Lines (7nf04358-) Part 1 Of 2

Travel Motor Lines (7nf1-04357) - Part 2 Of 2

Traveling Control - Part 2 Of 2

Traveling Control Part 1 Of 2

Tread (7nf1-01789)

Upper Structure Lines (For 2 Pumps Flow Confluence Hyd. Line Group)

Upper Structure Lines

Upper Structure Lines Part 2 Of 2 For Base Machine Hyd. Lines Group (Common) (7nf1-03050)

Upper Structure Lines For Base Machine Hyd. Lines Group (Common) (7nf03051-)

Upper Structure Lines-Part 1 Of 2 For Base Machine Hyd. Lines Group (Common) (7nf1-03050)

Water Separator (7nf04358-)

Wiper Motor

Wire Net (For Air Conditioner) (7nf01790-)

Wiring Harness-Part 3 Of 3 (7nf04358-)

Wiring Harness-Part 3 Of 3 (7nf1-00125)

Wiring Harness-Part 2 Of 3 (7nf00126-04357)

Wiring Harness-Part 1 Of 3 (7nf1-00125)

Wiring Harness-Part 3a Of 3 (7nf00126-04357)

Wiring Harness-Part 2 Of 3 (7nf04358-)

Wiring Harness-Part 1 Of 3 (7nf04358-)

Wiring Harness (For Cold Weather Starting Kit) (7nf00126-)

Wiring Harness (For Automatic Swing Brake) (7nf1-00125)

Wiring Harness (For Automatic Swing Brake) (7nf00126-01789)

Wiring Harness-Part 1 Of 3 (7nf00126-04357)

Wiring Harness-Part 2a Of 3 (7nf00126-04357)

Wiring Harness-Part 2 Of 3 (7nf1-00125)

Wiring Harness-Part 3 Of 3 (7nf00126-04357)

Working Control Part 1 Of 3

Working Control - Part 3 Of 3

Working Control Part 2 Of 3

Working Lights Part 1 Of 2

Working Lights-Part 2 Of 2

E120B serial number reference

The PIN plate is typically located on the machine frame. The prefix consists of the first three characters of the serial number.

Prefix	Identifies	Notes
S4KT	E120B Hydraulic Excavator	Confirmed via aftermarket parts listings for E120B/E110B hydraulic oil coolers and radiator cores. Serial prefix S4KT is explicitly tied to the E120B in supplier fitment data.

Frequently asked questions

What engine powers the E120B?

The Caterpillar E120B is equipped with a Caterpillar 3114 engine, providing 84 hp (62.7 kW) of gross power.

What is the operating weight of this machine?

The operating weight varies by configuration but is generally listed between 12500 kg (27,557 lb) and 12800 kg (28,219 lb).

What replaced the E120B?

Specific successor model information is not documented in the provided technical literature.

What E120B owners discuss

What are the common causes of poor travel performance or slow travel speed on an E120B when hydraulic oil is warm?

Issues often stem from relief valves being out of factory specification. Specifically, check the main relief and sub-system relief pressures. Additionally, verify the left and right crossover pressure reliefs, as improper adjustment can cause loss of power during uphill travel or slow speeds in high-speed mode. Check for worn seals in the center swivel, which is a common failure point on E-series machines.

What hydraulic behavior indicates potential internal bypassing or control valve issues during stick/boom operation?

If the engine bogs down or stalls specifically when using multiple joystick functions simultaneously (such as stick out and swing), it may indicate internal bypassing in the stick cylinder. Check the cylinder for heat to identify bypass. Other symptoms include power loss during lever engagement, which can be caused by hydraulic pressure drops or sticking control valves.

What is a known cause for intermittent 'banging' or sticking sensations during swing operation?

A noticeable bang or a feeling of stickiness when starting to swing may indicate a failing swing motor or issues with the swing brake. It is also recommended to inspect the servo pilot lines and the center swivel seals, as worn seals in this area are common on E120B models.

What engine specifications and fuel requirements are standard for the Caterpillar E120B?

The E120B is typically equipped with a Caterpillar 3114 engine featuring a displacement of 269 cu in (4,402 cu cm) and net power of 84 hp (63 kw). The fuel capacity is 66 gal (250 l).

What should be inspected regarding the undercarriage and hydraulic system when evaluating a used E120B?

Inspect the center swivel seals for leaks, as this is a frequent maintenance item. For the undercarriage, check the track gauge (7 ft / 2 m) and shoe size (20 in / 50 cm). Regarding the hydraulic system, verify the relief valve pressure is at 4270 psi and check the hydraulic oil cooler for condition.

What should a buyer check when purchasing a used E120B to avoid major repair costs?

Thoroughly inspect the major systems, specifically the hydraulic pumps, swing motor, and travel motors, for signs of lack of maintenance. Verify the electrical system configuration, as some units utilize a 24 volt system requiring two batteries to start. Ensure all hydraulic cylinders are checked for heat to rule out internal bypassing.

Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.

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