New Holland Hydraulic Excavator MH6.6, MH8.6 Workshop Manual PDF

This workshop manual covers the New Holland MH6.6 and MH8.6 hydraulic excavators. It explains how the machine’s systems work and provides service specifications and step-by-step repair procedures, supported by illustrations and circuit diagrams.

The procedures are intended for qualified service personnel. Follow the manufacturer’s instructions and use the specified special tools where required.

Service and Repair Coverage

Alongside service specifications and recommended maintenance materials, the manual provides adjustment and replacement information. It identifies the special tools used for cylinder work and for servicing axles and gearboxes.

The electrical and electronic sections explain the machine’s wiring and control systems, including the central electronic unit and electro-hydraulic pilot control. Circuit diagrams and component locations support fault tracing. The manual also covers CAN bus components, ESX coding and electronic load-limit regulation.

The hydraulic section follows power flow through the machine and explains individual circuits and combined functions. It includes attachment circuits for boom-adjusting and monoblock-boom equipment. Calibration and performance testing are also covered, along with troubleshooting and repair instructions.

Table of Contents

Safety Instructions

Personal safety instructions
Safety instructions before starting work
Working from the operator’s seat only
Never take passengers on the machine
Safety instructions for machine operation
Taking care during operation
Distance from overhead power lines
Safety instructions for maintenance and servicing
Warning and instruction signs
Organizational measures

Technical Data and Specification

General service data
Foreword
Data sheet for MH6.6 cylinders
Data sheet for MH8.6 cylinders
Bucket-induced protrusion
SI and additional units
Conversion tables, Part 1
Conversion tables, Part 2
Calculation examples
Tightening torques
Special tools for cylinders
Special tools for axles and gearboxes
Spacers

Machine Structure

Machine construction
Description of the machine with boom-adjusting equipment
Description of the machine with monoblock-boom equipment
Superstructure components: overview
Engine assembly components: overview
Hydraulic system components: overview
Drive unit components: overview
Undercarriage components: overview

The Electrical System

Fundamentals
Automotive electrical systems
Cable harnesses
Fuses
Checking and replacing fuses
Table of fuses

Electrical Circuit Diagrams

Electrical circuit diagrams for supplementary functions
Layout of electrical components
Electrical system: central electronics behind the driver’s seat
Electrical system for electro-hydraulic pilot control
Electrical system for the pilot control unit, solenoid valves, sensors and switches
Electrical system in the engine compartment
Electrical system for the undercarriage control block
Electrical system for undercarriage stabilization
Electrical components by code number

Electronics

Control
Introduction
Electronic control unit
Power supply
Components on CAN bus 1
Components on CAN bus 2
ESX coding
PCS: Power Control System
PCS components

Hydraulic System

Working, slewing and pilot-control circuits in the superstructure
Working, travel and pilot-control circuits in the undercarriage
Hydraulic circuit diagrams
Drive unit
Control block
Pilot-control system
Travel circuit of the 20 km/h version
Travel circuit of the 25/30 km/h version
Braking, steering and fan circuit
Undercarriage stabilizers
Boom cylinder circuit with regeneration circuit
Bucket cylinder circuit
Stick cylinder circuit with regeneration function
Adjusting cylinder circuit with pressure compensator and relief valve
Combined functions
Hydraulic hammer circuit: boom-adjusting equipment
Hammer circuit with auxiliary function: boom-adjusting equipment
Shears/crusher circuit: boom-adjusting equipment
Hydraulic hammer circuit: monoblock-boom equipment
Hammer circuit with auxiliary function: monoblock-boom equipment
Shears/crusher circuit: monoblock-boom equipment
Slewing system
Grab rotation mechanism

Calibration

Before undertaking calibration work
Display, service and calibration

Troubleshooting and Repair

Repair instructions
General information
Superstructure components
Link between superstructure and undercarriage
Components
Undercarriage components
Equipment and components
Wear parts
Engine

Delivery (Instant Download)

After payment, the PDF manual is sent to the email address provided with your order, usually within 1–10 minutes. Please check that your email address is correct at checkout.

Printing and Support

All pages of the PDF are printable. You can print the procedures you need for a particular job and keep them beside you in the workshop.

For questions about the manual or help with your order, contact our support team. After-sales support is available.