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Kubota KX91-3, KX101-3 Excavator Workshop Repair Manual

Kubota KX91-3, KX101-3 Excavator Workshop Repair Manual

$33.00

🚜 Equipment
Brand	Kubota
Type	Excavator
Model	KX91-3, KX101-3
📄 Documents
Type	Repair Manual
Publication	97899-60520
Language	English
Format	PDF
No of Pages	610

The Kubota KX91-3 and KX101-3 Mini Excavators are compact, versatile machines engineered for construction, landscaping, and utility projects where precision, maneuverability, and reliable performance are essential. Equipped with efficient Kubota diesel engines, these excavators deliver the power and fuel efficiency required for mid-sized excavation tasks, while maintaining a compact footprint that allows them to operate in restricted job sites.

The KX91-3 features a 28 hp Kubota diesel engine and an operating weight of approximately 3,225 kg, with a maximum digging depth of 3.17 m and reach of about 5.0 m. Compact in design, with a transport width of just over 1.55 m, it is suited for trenching, grading, and small-scale earthmoving tasks. The larger KX101-3 provides enhanced performance with a 30 hp engine, an operating weight of around 3,590 kg, and increased digging reach of 5.4 m with a depth of 3.3 m. Both machines are equipped with 300 mm tracks and deliver strong breakout forces for demanding digging applications.

The workshop repair manual provides comprehensive coverage for both models, including machine body servicing, hydraulic system specifications, pump and valve assemblies, swivel and travel motors, cylinders, and the full electrical system. It contains detailed disassembly and assembly procedures, torque specifications, lubrication schedules, wiring diagrams, hydraulic schematics, and troubleshooting guides. Special sections also cover the Intelligent Control System (ICS), auto idle functions, safety relays, and service testing procedures to ensure long-term reliability and performance.

Key Highlights

KX91-3: ~3,225 kg operating weight, 28 hp engine, 3.17 m digging depth
KX101-3: ~3,590 kg operating weight, 30 hp engine, 3.3 m digging depth, extended reach of 5.4 m
Transport width: ~1.55 m for both models, suited for narrow job sites
Bucket capacity: up to 0.058 m³ for efficient material handling
Hydraulic system includes pump, valves, and arm regeneration circuits for smooth operation
ICS and auto-idle functions improve fuel efficiency and operator control
ROPS/TOPS-compliant cab with ergonomic controls for operator safety and comfort
Manual covers engine, hydraulics, electrical systems, travel/swing motors, cylinders, and cab equipment
Includes torque specs, lubrication intervals, wiring/hydraulic schematics, and troubleshooting flowcharts
Designed for reliable performance, easy servicing, and long-term durability

Table of Content

📙 Table of Contents

Wsm_Kx91_101-3

WSM_KX91_101-3
- CONTENTS
- I. General
  - A. Body and engine identification marks
  - B. Safety precautions for servicing, disassembly and reassembly
    - a. Safety measures before starting work
      - (1) Work clothes
      - (2) Inspecting equipment and tools
      - (3) Keep workshop in order
    - b. Safety measures during work
      - (1) Protectors
      - (2) Team work
      - (3) Disassembly and assembly
      - (4) Cranes
      - (5) Others
    - c. Preparation for disassembly
      - (1) Cleaning
      - (2) Acceptance inspection
      - (3) Equipment and tools
    - d. Precautions for disassembly and reassembly
      - (1) Disassembly
      - (2) Reassembly
  - C. IMPORTANT SAFETY PROCESS AND CRITICAL FUNCTIONAL PROCESS
    - a. Essential Adhesives
    - b. Important Safety Process.
    - c. Important Critical Functional Process.
  - D. IMPORTANT INSPECTION ITEMS AFTER REASSEMBLING
    - a. Operate the Machine and check for Unusual Noise and Vibrations.
    - b. Make Sure the Safety decals and Wire harness Clamps are in their Specified Positions.
    - c. With the Machine Front in a Specified Posture, Check the Amount of Hydraulic Oil
  - E. SERVICING FUNDAMENTALS
    - a. Items for Servicing
    - b. O-ring, Oil seal, Circlip and Roll Pin
    - c. Piping
      - (1) General precautions
      - (2) Hydraulic hose
      - (3) Precautions in tightening the bolts and nuts
      - (4) Hose screw
      - Metric Size Hose
      - (5) Joint bodies
      - (6) Tightening torque table for hose clamp (Screw type)
      - (7) Nuts for piping
      - (8) Tightening torque of bolts and nuts
      - (9) Types and materials of bolts and nuts
- II. Machine body (Mechanism section)
  - A. Front attachment
    - a. Greasing points
    - b. Bucket interchangeability
  - B. Swivel frame and components
    - a. Accel lever (Standard-version)
      - (1) Engine RPM
      - (2) Accel lever operating force
    - b. Auto idle-version
      - (1) Accel lever side
      - (2) AI motor side
      - (3) Engine side
    - c. Accel cable
    - d. Swivel bearing
  - C. Track frame and components
    - a. Tension spring pre-set length
    - b. Additional parts to change from rubber track to iron track
    - c. Track tension adjustment
    - d. Grease tension cylinder, L
    - e. Drive sprocket
    - f. Rubber track
    - g. Iron track
- II. Machine body (Service section)
  - A. Specifications
    - a. Machine Weight
      - (1) KE, KDG, KUK version
      - (2) KTC, KCL, KTA version
    - b. Machine specifications
      - (1) KE, KDG, KUK version
      - (2) KTC, KCL, KTA version
    - c. Lever stroke and operating force
    - d. Dimensions of Parts
      - (1) Front pins
      - (2) Bucket
      - (3) Rubber crawler
      - (4) Iron crawler
      - (5) Track roller, idler, sprocket
      - (6) Dozer
      - (7) Parts weight
      - (8) Quantity Water and Oil
  - B. Front attachment
    - a. Parts designation
    - b. Exchange of bucket (Kubota Japan Bucket)
    - c. Exchange of bucket teeth and side cutter
    - d. Installing direction of dust seal
    - e. Installation of thrust collar on the swing bracket
    - e-1. Service tip to ease customer complaint
    - e-2. Swing bracket pin & bush.
    - e-3. Replacing the swing bracket support bush
    - e-4. Measuring the swing bracket looseness
    - f. Installing direction of fixing pin bolts
    - g. Front hoses and clamps
  - C. Upper Structure
    - a. Swivel bearing
    - b. Traveling lever
    - d. Traveling lever adjustment
    - e. Traveling lever lock
      - Adjusting the lever’s neutral position
    - f. Accelerator lever
      - (1) KE, KUK, KDG version
      - (2) KTC, KU, KTA version
    - g. Dozer lever
    - h. Swing pedal
    - i. Auxiliary port pedal
    - j. Location of links for each operation
  - D. Under carriage
    - a. Track tension device
    - b. Crawler installation
    - c. Track Roller and Upper Roller installation
- III. Engine (Mechanism section)
  - A. Specification & features
    - a. Specifications
    - b. Features
  - B. Fuel injection pump
    - a. Structure
    - b. Precaution of removing reassembly
      - (1) Removing injection pump
      - (2) Mounting of injection pump
      - (3) Engine stop lever installation
  - C. Radiator fan & coupling flange
    - a. Fan belt tension adjustment
    - b. Alternator mounting bolt torque:
    - c. Temp. sensor tightening torque:
    - d. Fan flange bolt tightening torque:
    - e. Bolt tightening torque of coupling flange
    - f. Coupling flange
  - D. Other parts
    - a. Fuel filter
    - b. Air filter
    - c. Thermostat
  - E. Technical Data
    - Engine Specifications
  - F. Performance Curve
- III. Engine (Engine WSM (Addition))
- IV. Hydraulic system (Mechanism section)
  - A. Features of hydraulic system
  - B. Hydraulic system specifications
  - C. Main pump
    - a. Structure & specifications
    - b. Performance curve
      - Variable displacement pump
      - Variable displacement pump
  - D. Control valve
    - a. Specifications
    - b. General view of control valve
    - c. Control valve circuit diagram
    - d. Control valve sectional view
    - e. Arm regeneration circuit
      - (1) Arm dump
      - (2) Arm Crowd
    - f. Oil flow of lock valve
      - (1) Operation of lock valve
      - (2) Boom operation
    - g. Function of lock valve (Anti-drift valve)
      - (1) Boom cylinder holding function
      - (2) Boom up function
      - (3) Boom-down function
    - h. Relief valve/Anti-cavitation valve
    - i. Straight travel circuit
    - j. Other functions
      - (1) Interval oil flow
  - E. Pilot valve
    - a. Structure & specifications
    - b. Pilot valve control diagram
  - F. Swivel motor
    - a. Structure & specifications
    - b. Function of negative brake
      - (1) Negative brake function (Unload condition)
      - (2) Negative brake release (On-load condition)
    - c. Function of valve section
      - (1) Make-up valve
      - (2) Function of shockless valve
      - (4) Relief valve
      - (5) Shockless piston
      - (6) Make-up poppet
  - G. Rotary joint (Swivel joint)
  - H. Travel motor
    - a. Structure & specifications : KTC, KCL, KTA version
      - (1) Relief valve
      - (2) Shockless piston
      - (3) Counter balance valve
      - (4) High pressure selection spool
      - (5) Hi-Lo change spool
    - b. Operation of piston motor
    - c. Function of shockless valve
  - I. Other components
    - a. Change valve with accumulator : EU version
      - (1) Pressure relief valve: a4
      - (2) Pressure relief valve: a5
      - (3) Electro-magnetically directional spool valves
    - b. Pilot filter
    - c. Return filter
    - d. Suction strainer
  - J. Hydraulic circuit diagram
    - a. KX91-3 European – version
    - b. KX101-3 European – version
    - c. KX91-3 KTC, KCL – version
    - d. KX91-3 KTA – version
    - d. Hydraulic components layout
    - a. Actual service port flow: KX91-3 KTA-version only
    - d. Installing direction of dust seal
    - e. Installation of thrust collar on the swing bracket
- IV. Hydraulic system (Service section)
  - A. Troubleshooting
    - a. Common Circuit
    - b. Front Attachment
    - c. Swivel Circuit
    - d. Travel Circuit
  - B. Specifications
    - a. Relief valve pressure setting
    - b. Pump
      - (1) KE, KDG, KUK version
      - (2) KTC, KCL, KTA version
    - c. Cylinder
      - (1) Cylinder operating speed
      - (2) Cylinder natural fall amount
      - (3) Cylinder specifications
    - d. Swivel Performance
      - (1) KE, KDG, KUK version
    - e. Traveling Performance
      - (1) KE, KDG, KUK version
      - (2) KTC, KCL, KTA version
  - C. Testing
    - a. Testing Instruments & special tools
    - b. Pump flow
    - c. Pilot pressure
      - (1) Primary pressure
      - (2) Secondary pressure
    - d. Main relief valve
    - e. Overload relief valve
    - f. Swivel brake valve pressure
    - g. Traveling motor drain amount
    - h. Swivel motor drain amount
    - i. Swivel motor block performance
    - j. Traveling motor block performance
    - k. Operating speed
      - (1) Checking each operating speed.
      - (2) Boom cylinder
      - (3) Arm cylinder
      - (4) Bucket cylinder
      - (5) Swing cylinder
      - (6) Dozer cylinder
      - (7) Swivel speed
      - (8) Traveling speed
    - l. Straight travel performance
    - m. Cylinder natural fall amount
    - n. Control and Traveling lever operating force
    - o. Lever stroke
    - p. Specification sheet : Drain amount, Swivel motor
    - q. Specification sheet : Drain amount, Wheel motor (Travel motor)
  - D. Disassembling and Assembling
    - a. Coupling flange
    - b. Pump
      - (1) Components of pump [KX91-3, KX101-3]
      - (2) Adaptor installation on the pump
      - (3) Disassembling and assembling
    - c. Control valve and relief valve
      - (1) General precautions for servicing control valve
      - (2) Components of the control valve
      - (3) Inner parts of the control valve
      - (4) Adaptor installation
      - (5) Disassembling of the control valve
    - d. Pilot valve
      - (1) Components of the pilot valve
      - (2) Adaptor and hose installation
      - (3) Disassembling and assembling (KTC, KCL, KTA version)
      - (4) Trouble shooting
    - e. Swivel motor (KTC, KCL, KTA version)
      - (1) Components of the swivel motor
      - (2) Inner parts of the swivel motor
      - (3) Assembling of the swivel motor (KTC, KCL, KTA version)
    - f. Traveling motor
      - (1) Components of the traveling motor (KTC, KCL, KTA version)
      - (2) Inner parts of the traveling motor
      - (3) Assembling of the traveling motor (KTC, KCL, KTA version)
    - g. Rotary joint
      - (1) Inner parts of the rotary joint
      - (2) Assembling of the rotary joint
      - (3) Adaptor installation on the rotary joint (KTC, KCL, KTA version)
    - h. Cylinder (KE, KDG, KUK version)
      - (1) Inner parts of the cylinder
      - (2) Tightening torque
      - (3) Disassembling and assembling
    - h. Cylinder (KTC, KCL, KTA version)
      - (1) Inner parts of the cylinder
      - (2) Tightening torque
      - (3) Disassembling and assembling
      - (4) Inspection
    - i. Other hydraulic device
      - (1) Change valve
      - (2) TPSS valve (KTC, KCL, KTA version only)
    - j. Hose
      - (1) Pilot hose
      - (2) Delivery hose
      - (3) Hose connection around Rotary Joint (KTC, KCL, KTA version)
      - (4) Hose connection on control valve (KTC, KCL, KTA version)
      - (5) Return circuit (KTC, KCL, KTA version)
      - (6) Drain circuit (KTC, KCL, KTA version)
      - (7) Traveling motor and dozer
- V. Electrical system (Mechanism section)
  - A. Outline
  - B. Components & harness layout
  - C. Couplers, KX91-3, 101-3 Standard version
  - D. Function of main circuit
    - a. Battery circuit (Standard-version)
    - b. Safety Relay circuit (Automatic release function) Standard-version
      - (1) Operation
      - (2) Function chart of auto release controller
    - c. Auto glow circuit (Standard-version)
      - (1) Function
    - d. Fuel control circuit (STD, AI-version)
      - (1) Function
      - (2) Engine stop solenoid (STD, AI-version)
    - e. Engine oil pressure sensor circuit (STD, AI-version)
      - Oil switch
    - f. Horn circuit (STD, AI-version)
      - (1) Structure
      - (2) Function
      - (3) Current flow
      - (4) Horn circuit
    - g. Cab & Working lamp circuit (STD, AI-version)
    - h. Meter panel (Standard-version)
    - i. Heater circuit (STD, AI-version)
    - j. Travel hi-speed control circuit (STD, AI-version)
    - k. Auto idle control system (AI-version)
      - (1) Purpose
      - (2) Auto idle function mechanism
      - (3) AI function layout
      - (4) Behavior when the control lever is returned to neutral
      - (5) Behavior when the control lever is operated:
      - (6) AI motor normal-turn circuit
      - (7) AI motor reverse-turn circuit
    - l. Battery direct line (AI-version)
    - m. Starter lock relay & auto release relay (AI-version)
      - (1) Safety start system
      - (2) Auto release function (AI-version)
    - n. Self holding relay circuit (AI-version)
    - o. Water temp. sensor circuit (AI-version)
    - p. Meter panel (AI-version)
    - q. AI controller unit (AI-version)
  - E. Structure and function of main components
    - a. Key switch (Engine starter switch)
    - b. Water temp. sensor
    - c. Safety lever lock switch, travel hi-low pedal switch
    - d. Relay
    - e. Engine speed sensor
    - f. Accel sensor, governor sensor
    - g. AI pressure switch
    - h. Fundamentals
  - F. Circuit diagram
    - a. Electric Circuit Diagram: KX91-3, 101-3 (Standard-version)
    - b. Functional Electric Circuit Diagram: KX91-3, 101-3 (Standard-version)
    - c. Electric Circuit Diagram: KX101-3 (AI-version, EU)
    - d. Functional Electric Circuit Diagram: KX101-3 (AI-version, EU)
    - e. Cab Electrical Diagram
      - KX91-3, KTC, KCC, KTA-version
    - f. Harness couplers of KX101-3, AI-version
- V. Electrical system (Service section)
  - A. Troubleshooting
    - a. General
      - (1) How to diagnose
      - (2) INSPECTION OF HARNESS CONNECTOR
      - (3) Inspection
      - (4) INSPECTION INSTRUMENTS
      - (5) CHECKING SWITCHES
      - (6) Checking fuses
      - (7) Solenoid test method
      - (8) Checking relays
      - (9) Checking cables and wires
      - (10) HANDLING ON-VEHICLE BATTERY
    - b. Front attachment
      - (1) Working lamp failure
      - (2) Safety lever lock circuit malfunction
    - c. Engine electrical system
      - (1) Engine oil pressure failure
      - (2) Water temp. sensor circuit malfunction
      - (3) Fuel sensor circuit
      - (4) Engine stop solenoid
      - (5) Charging system malfunction
      - (6) Auto glow controller
      - (7) Auto release controller
    - d. Auto idle system
      - (1) Troubleshooting outline
      - (2) AI pressure switch test method
      - (3) Accel & governor sensor test method
      - (4) AI motor test method
      - (5) Engine speed sensor
      - (6) Auto glow circuit
    - e. AI version: AI controller (built-in microcomputer) Cases of trouble diagnosis with circuit tester
      - (1) “Water temperature sensor” line in trouble
      - (2) Other circuitry layouts and their trouble diagnosis
    - f. Auto Idle (AI) version: Trouble diagnosis with lamp
      - (1) General
      - (2) Display and identification of errors in operating mode
      - (3) Entering the service mode
      - (4) Working on the 5 menus in the service mode
      - (5) Working on the 3 menus in the service mode
      - (6) Working on the AI motor drive menus in the service mode
      - (7) Entering the setup mode
      - (8) Lamp-identified fail symptoms, trouble spots and possible causes
- VI. Optional Units
  - A. KTA-version
    - a. Actual service port flow : KX91-3 KTA-version only
      - 1. Test method; Testing circuit
      - 2. Service port flow test sample.
      - 3. P-Q performance of pump 2.
      - 4. Actual service port flow : KX91-3 KTA-version
      - 5. Actual service port flow : U35-3 KTA-version
    - b. Breaker performance test sample : KTA-version only
      - 1. Test machine :
      - 2. Heat balance test condition
      - 3. Breaker operating result : Sample Data
      - 4. Service port flow for breaker operation, theoretical
      - 5. Breaker operation test procedure
      - 6. Test Data Sheet
      - 7. Krupp breaker information
      - 8. SERVICE PORT OIL FLOW (KTA Version)
  - B. KTC-version, optional kit
    - a. Installation Manual for Canopy Kit
      - 1. Introduction
      - 2. Item list of canopy kit
      - 3. Installation instruction
    - b. Installation Manual for Canopy Kit
      - 1. Introduction
      - 2. Item list of canopy kit
      - 3. Installation instruction
    - c. Working Light Installation Manual
      - 1. Introduction
      - 2. Item list of light kit
    - d. Installation Manual for Cabin Kit
      - 1. Introduction
      - 2. Item list of cabin kit
      - 3. Installation instruction
    - e. Installation Manual for Cabin Kit
      - 1. Introduction
      - 2. Item list of canopy kit
      - 3. Installation instruction
    - f. Item List of Heat Insulator Kit
      - 1. Introduction
      - 2. Item list
      - 3. Overview
      - 4. Heat Insulator Installation Instructions
      - 5. Spark Arresting Muffler Installation Instructions
      - 6. KX3 Spark Arrester Muffler Maintenance at Every 250 Excavator Service Hours
    - g. Installation Manual Auxiliary Relief Valve and Cylinder Mounting Bracket Kit
      - 1. Introduction
      - 2. SAFE OPERATION BEFORE THUMB INSTALLATION
      - 3. WELDING INSTRUCTIONS
      - 4. Parts list
      - 5. Installation instructions
    - h. THIRD LINE KIT
      - 1. Introduction
      - 2. Preparation for installation
      - 3. Installation instruction
      - 4. Inspection after installation
    - i. STEEL CRAWLER KIT (Convert tracks from rubber to steel) INSTALLATION INSTRUCTION FOR MOUNTING STEEL TRACKS
      - 1. Removing rubber tracks
      - 2. Changing the tension of spring
      - 3. Mounting iron crawlers
      - 4. Adjustment of crawlers (Steel tracks)
    - j. STEEL CRAWLER KIT (Convert tracks from rubber to steel) INSTALLATION INSTRUCTION FOR MOUNTING STEEL TRACKS
      - 1. Removing rubber tracks
      - 2. Changing the tension of spring
      - 3. Mounting iron crawlers
      - 4. Adjustment of crawlers (Steel tracks)

Specification

Specification	Kubota KX91-3 Mini Excavator	Kubota KX101-3 Mini Excavator
Operating Weight	~7,110 lb (3,225 kg)	~3.59 t (3,590 kg)
Engine Power	28 hp net (20 kW)	~30 PS (~30 hp / 22.9 kW)
Max Digging Depth	~3.17 m (10 ft 5 in)	~3.3 m
Max Reach	~5.0 m (17 ft)	~5.4 m
Bucket Capacity	Not specified	0.058 m³
Transport Dimensions (W × L × H)	~5 ft 1 in wide; 15 ft 7 in long; 8 ft 0 in high	~1.55 m × 4.92 m × 2.44 m
Track Width	~300 mm	~300 mm

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