Description

Gehl Z25, Mustang 250Z Compact Excavator Repair Service Manual

Language: English
Format: PDF
Applicable for the Gehl Excavator  Model Gehl Z25, Mustang 250Z

• Gehl Z25, Mustang 250Z Excavator Repair Service Manual – 576 Pages
• Gehl Z25, Mustang 250Z Excavator Repair Parts Manual – 326  Pages
• Gehl Z25, Mustang 250Z Excavator Repair Parts Manual – 295  Pages

Table of Content of the Gehl Z25, Mustang 250Z Excavator Manual:
CHAPTER 1
GENERAL CAUTIONS FOR MAINTENANCE WORK
1-1 Correct Work ………………………………………………………………………………………………………………………………………………….. 1-1-1
1-2 Safety Precautions ………………………………………………………………………………………………………………………………………….. 1-2-1
1-3 Preparations…………………………………………………………………………………………………………………………………………………… 1-3-1
1-4 Cautions for Disassembly and Reassembly………………………………………………………………………………………………………… 1-4-1
1-5 Cautions for Removal and Installation of Hydraulic Equipment ……………………………………………………………………………… 1-5-2
1-6 Cautions for Removal and Installation of Hydraulic Piping…………………………………………………………………………………….. 1-6-2
1-7 Cautions for Handling Seals……………………………………………………………………………………………………………………………… 1-7-3
1-8 Correct Installation of Hydraulic Hose………………………………………………………………………………………………………………… 1-8-3
1-9 Specifications of Hydraulic Hose……………………………………………………………………………………………………………………….. 1-9-6
1-10 Air Release of Hydraulic Equipment……………………………………………………………………………………………………………….. 1-10-8
CHAPTER 2
TECHNICAL DATA
2-1 Specifications …………………………………………………………………………………………………………………………………………………. 2-1-1
2-2 Outline Drawing and Working Area……………………………………………………………………………………………………………………. 2-2-1
2-3 Weight List of Main Parts …………………………………………………………………………………………………………………………………. 2-3-1
2-4 Lifting Capacity List …………………………………………………………………………………………………………………………………………. 2-4-1
2-5 Specifications for Attachment……………………………………………………………………………………………………………………………. 2-5-1
2-6 Periodic Inspection and Servicing ……………………………………………………………………………………………………………………… 2-6-1
2-7 Fuel, Lube Oil and Grease Recommended…………………………………………………………………………………………………………. 2-7-1
2-8 Hydraulic Circuit Schematic ……………………………………………………………………………………………………………………………… 2-8-1
2-9 Wiring Diagram……………………………………………………………………………………………………………………………………………….. 2-9-1
CHAPTER 3
SERVICE STANDARDS
3-1 Machine Performance ……………………………………………………………………………………………………………………………………… 3-1-1
3-2 Engine …………………………………………………………………………………………………………………………………………………………… 3-2-1
3-3 Undercarriage ………………………………………………………………………………………………………………………………………………… 3-3-1
3-3-1 Rubber Track Specifications …………………………………………………………………………………………………………………….. 3-3-1
3-3-2 Common Specifications of Rubber Crawlers……………………………………………………………………………………………….. 3-3-2
3-4 Controls…………………………………………………………………………………………………………………………………………………………. 3-4-1
3-5 Hydraulic Equipment ……………………………………………………………………………………………………………………………………….. 3-5-1
3-5-1 Hydraulic Cylinders …………………………………………………………………………………………………………………………………. 3-5-1
3-6 Implement ……………………………………………………………………………………………………………………………………………………… 3-6-1
3-6-1 Front Attachments …………………………………………………………………………………………………………………………………… 3-6-1
3-6-2 Blade Moving Device……………………………………………………………………………………………………………………………….. 3-6-2
3-6-3 Bucket Teeth ………………………………………………………………………………………………………………………………………….. 3-6-2
3-7 List of Tightening Torque …………………………………………………………………………………………………………………………………. 3-7-1
3-7-1 Machine…………………………………………………………………………………………………………………………………………………. 3-7-1
3-7-2 Engine …………………………………………………………………………………………………………………………………………………… 3-7-6
3-8 Pressure Adjustment……………………………………………………………………………………………………………………………………….. 3-8-1
3-8-1 Relief Valves ………………………………………………………………………………………………………………………………………….. 3-8-1
3-8-2 Swing Brake Valve ………………………………………………………………………………………………………………………………….. 3-8-4
3-8-3 Cut-Off Valve………………………………………………………………………………………………………………………………………….. 3-8-5
CHAPTER 4
ENGINE
4-1 Safety ……………………………………………………………………………………………………………………………………………………………. 4-1-1
4-1-1 Safety Statements …………………………………………………………………………………………………………………………………… 4-1-1
4-1-2 Safety Precautions ………………………………………………………………………………………………………………………………….. 4-1-2
4-2 Engine …………………………………………………………………………………………………………………………………………………………… 4-2-1
4-2-1 Before You Begin Servicing ……………………………………………………………………………………………………………………… 4-2-1
4-2-2 Introduction…………………………………………………………………………………………………………………………………………….. 4-2-2
4-2-3 Special Service Tools………………………………………………………………………………………………………………………………. 4-2-3
4-2-4 Measuring Instruments…………………………………………………………………………………………………………………………….. 4-2-5
4-2-5 Cylinder Head…………………………………………………………………………………………………………………………………………. 4-2-7
4-2-6 Disassembly of rocker arm assembly……………………………………………………………………………………………………….. 4-2-10
4-2-7 Measuring and Adjusting Valve Clearance ……………………………………………………………………………………………….. 4-2-20
4-2-8 Crankshaft and Camshaft Components ……………………………………………………………………………………………………. 4-2-22
4-3 Fuel System …………………………………………………………………………………………………………………………………………………… 4-3-1
4-3-1 Before You Begin Servicing ……………………………………………………………………………………………………………………… 4-3-1
4-3-2 Introduction…………………………………………………………………………………………………………………………………………….. 4-3-2
4-3-3 Fuel System Specifications and Tools ……………………………………………………………………………………………………….. 4-3-6
4-3-4 Fuel System Diagram………………………………………………………………………………………………………………………………. 4-3-8
4-3-5 Fuel System Components ………………………………………………………………………………………………………………………… 4-3-9
4-4 Cooling System………………………………………………………………………………………………………………………………………………. 4-4-1
4-4-1 Before You Begin Servicing ……………………………………………………………………………………………………………………… 4-4-1
4-4-2 Introduction…………………………………………………………………………………………………………………………………………….. 4-4-2
4-4-3 Cooling System Diagram………………………………………………………………………………………………………………………….. 4-4-2
4-4-4 Engine Coolant Pump Components …………………………………………………………………………………………………………… 4-4-3
4-4-5 Engine Coolant System Check………………………………………………………………………………………………………………….. 4-4-4
4-4-6 Engine Coolant Pump ……………………………………………………………………………………………………………………………… 4-4-4
4-5 Lubrication System………………………………………………………………………………………………………………………………………….. 4-5-1
4-5-1 Before You Begin Servicing ……………………………………………………………………………………………………………………… 4-5-1
4-5-2 Introduction…………………………………………………………………………………………………………………………………………….. 4-5-2
4-5-3 Oil Pump Service Information……………………………………………………………………………………………………………………. 4-5-2
4-5-4 Lubrication System Diagram …………………………………………………………………………………………………………………….. 4-5-3
4-5-5 Checking Engine Oil Pressure ………………………………………………………………………………………………………………….. 4-5-4
4-5-6 Trochoid Oil Pump…………………………………………………………………………………………………………………………………… 4-5-4
4-6 Starter Motor ………………………………………………………………………………………………………………………………………………….. 4-6-1
4-6-1 Before You Begin Servicing ……………………………………………………………………………………………………………………… 4-6-1
4-6-2 Introduction…………………………………………………………………………………………………………………………………………….. 4-6-2
4-6-3 Starter Motor Specifications ……………………………………………………………………………………………………………………… 4-6-2
4-6-4 Starter Motor Troubleshooting…………………………………………………………………………………………………………………… 4-6-3
4-6-5 Starter Motor Components ……………………………………………………………………………………………………………………….. 4-6-4
4-6-6 Starter Motor ………………………………………………………………………………………………………………………………………….. 4-6-5
4-7 Alternator……………………………………………………………………………………………………………………………………………………….. 4-7-1
4-7-1 Before You Begin Servicing ……………………………………………………………………………………………………………………… 4-7-1
4-7-2 Introduction…………………………………………………………………………………………………………………………………………….. 4-7-2
4-7-3 Alternator Specifications…………………………………………………………………………………………………………………………… 4-7-2
4-7-4 Alternator Troubleshooting ……………………………………………………………………………………………………………………….. 4-7-3
4-7-5 Alternator Components ……………………………………………………………………………………………………………………………. 4-7-4
4-7-6 Alternator Wiring Diagram ………………………………………………………………………………………………………………………… 4-7-5
4-7-7 Alternator Standard Output ………………………………………………………………………………………………………………………. 4-7-6
4-7-8 Alternator……………………………………………………………………………………………………………………………………………….. 4-7-7
4-8 Electric Wiring ……………………………………………………………………………………………………………………………………………….. 4-8-1
4-8-1 Electric Wiring Precautions ……………………………………………………………………………………………………………………… 4-8-1
4-9 Failure Diagnosis …………………………………………………………………………………………………………………………………………… 4-9-1
4-9-1 Special Service Tools………………………………………………………………………………………………………………………………. 4-9-1
4-9-2 Troubleshooting By Measuring Compression Pressure ………………………………………………………………………………… 4-9-2
4-10 Troubleshooting …………………………………………………………………………………………………………………………………………. 4-10-1
4-10-1 Quick Reference Table for Troubleshooting……………………………………………………………………………………………. 4-10-1
CHAPTER 5
ELECTRIC SYSTEM
5-1 Electric Equipment of Machine………………………………………………………………………………………………………………………….. 5-1-1
5-1-1 Parts Layout of Electrical Equipment …………………………………………………………………………………………………………. 5-1-1
5-1-2 LCD Monitor and Alarm Systems ………………………………………………………………………………………………………………. 5-1-7
5-2 Circuit Description of Engine Start and Stop……………………………………………………………………………………………………….. 5-2-1
5-2-1 Engine Start and Stop ……………………………………………………………………………………………………………………………… 5-2-1
5-2-2 Battery charge ………………………………………………………………………………………………………………………………………… 5-2-3
5-3 Automatic Deceleration System ………………………………………………………………………………………………………………………… 5-3-1
5-3-1 Main Components and Wiring Diagram ……………………………………………………………………………………………………… 5-3-1
5-3-2 Function and Control ……………………………………………………………………………………………………………………………….. 5-3-3
5-4 Error Code List ……………………………………………………………………………………………………………………………………………….. 5-4-1
CHAPTER 6
HYDRAULIC SYSTEM
6-1 Outline…………………………………………………………………………………………………………………………………………………………… 6-1-1
6-1-1 Control Valve Operation …………………………………………………………………………………………………………………………… 6-1-3
6-1-2 Additional Operation of Control Valve ………………………………………………………………………………………………………… 6-1-4
6-2 Circuit Operation …………………………………………………………………………………………………………………………………………….. 6-2-1
6-2-1 Boom …………………………………………………………………………………………………………………………………………………….. 6-2-1
6-2-2 Arm……………………………………………………………………………………………………………………………………………………….. 6-2-2
6-2-3 Bucket …………………………………………………………………………………………………………………………………………………… 6-2-3
6-2-4 Swing…………………………………………………………………………………………………………………………………………………….. 6-2-4
6-2-5 Boom Swing …………………………………………………………………………………………………………………………………………… 6-2-5
6-2-6 Blade …………………………………………………………………………………………………………………………………………………….. 6-2-6
6-2-7 Travel ……………………………………………………………………………………………………………………………………………………. 6-2-7
6-2-8 Non-Deviation Travel (with Boom, Arm, Bucket or Boom Swing Operation)…………………………………………………….. 6-2-8
6-2-9 Simultaneous Operation of Boom Up and Arm Retract…………………………………………………………………………………. 6-2-9
6-2-10 Simultaneous Operation of Boom Up and Bucket…………………………………………………………………………………….. 6-2-10
6-2-11 Simultaneous Operation of Boom Up and Swing ……………………………………………………………………………………… 6-2-11
6-2-12 Simultaneous Operation of Arm and Bucket ……………………………………………………………………………………………. 6-2-12
6-2-13 Hydraulic P.T.O. ………………………………………………………………………………………………………………………………….. 6-2-13
6-2-14 Quick Coupler (Quick coupler spec.)………………………………………………………………………………………………………. 6-2-14
6-2-15 Travel Alarm ……………………………………………………………………………………………………………………………………….. 6-2-15
6-2-16 Auto Deceleration (Optional) …………………………………………………………………………………………………………………. 6-2-16
6-3 Hydraulic Pump………………………………………………………………………………………………………………………………………………. 6-3-1
6-4 Control Valve………………………………………………………………………………………………………………………………………………….. 6-4-1
6-5 Pilot Valve ……………………………………………………………………………………………………………………………………………………… 6-5-1
6-6 Swing Motor …………………………………………………………………………………………………………………………………………………… 6-6-1
6-7 Travel Motor …………………………………………………………………………………………………………………………………………………… 6-7-1
6-8 Proportional solenoid valve ………………………………………………………………………………………………………………………………. 6-8-1
6-9 Pilot Check Valve (For Quick Coupler Circuit) …………………………………………………………………………………………………….. 6-9-1
6-10 2-way valve ………………………………………………………………………………………………………………………………………………… 6-10-1
CHAPTER 7
ADJUSTMENT AND REPAIR
7-1 Engine and Electric Equipment …………………………………………………………………………………………………………………………. 7-1-1
7-1-1 Removal and Reinstallation of Engine ……………………………………………………………………………………………………….. 7-1-1
7-1-2 Removal and Reinstallation of Starter Motor……………………………………………………………………………………………… 7-1-13
7-1-3 Removal and Reinstallation of Radiator and Oil Cooler ………………………………………………………………………………. 7-1-15
7-1-4 Removal and Reinstallation of Fan Belt ……………………………………………………………………………………………………. 7-1-20
7-2 Undercarriage ………………………………………………………………………………………………………………………………………………… 7-2-1
7-2-1 Outline …………………………………………………………………………………………………………………………………………………… 7-2-1
7-2-2 Points of Reassembly (Rubber Track) ……………………………………………………………………………………………………….. 7-2-2
7-2-3 Removal and Reinstallation of Track………………………………………………………………………………………………………….. 7-2-3
7-2-4 Removal and Reinstallation of Travel Motor ……………………………………………………………………………………………….. 7-2-4
7-2-5 Disassembly and Reassembly of Idler ……………………………………………………………………………………………………….. 7-2-6
7-2-6 Disassembly and Reassembly of Track Roller…………………………………………………………………………………………….. 7-2-9
7-2-7 Disassembly and Reassembly of Carrier Roller…………………………………………………………………………………………. 7-2-12
7-2-8 Installation of Floating Seal …………………………………………………………………………………………………………………….. 7-2-14
7-2-9 Drawings of Jig……………………………………………………………………………………………………………………………………… 7-2-15
7-3 Controls…………………………………………………………………………………………………………………………………………………………. 7-3-1
7-3-1 Mechanical Control Linkage ……………………………………………………………………………………………………………………… 7-3-1
7-3-2 Adjustment of Travel Levers……………………………………………………………………………………………………………………… 7-3-3
7-3-3 Adjustment of Blade Lever ……………………………………………………………………………………………………………………….. 7-3-4
7-3-4 Adjustment of Lock Lever…………………………………………………………………………………………………………………………. 7-3-5
7-4 Swing Bearing ………………………………………………………………………………………………………………………………………………… 7-4-1
7-5 Hydraulic Equipment ……………………………………………………………………………………………………………………………………….. 7-5-1
7-5-1 Removal and Reinstallation of Hydraulic Pump …………………………………………………………………………………………… 7-5-1
7-5-2 Removal and Reinstallation of Control Valve ………………………………………………………………………………………………. 7-5-3
7-5-3 Removal and Reinstallation of Pilot Valves (L and R)…………………………………………………………………………………… 7-5-7
7-5-4 Removal and Reinstallation of Swing Motor………………………………………………………………………………………………… 7-5-9
7-5-5 Removal and Reinstallation of Swivel Joint……………………………………………………………………………………………….. 7-5-11
7-5-6 Disassembly and Reassembly of Swivel Joint …………………………………………………………………………………………… 7-5-15
7-5-7 Disassembly and Reassembly of Hydraulic Cylinder ………………………………………………………………………………….. 7-5-18
7-5-8 Removal and Reinstallation of Hydraulic Oil Tank ……………………………………………………………………………………… 7-5-25
7-5-9 Piping Layout………………………………………………………………………………………………………………………………………… 7-5-32
7-6 Work Implements ……………………………………………………………………………………………………………………………………………. 7-6-1
7-6-1 Removal and Reinstallation of Work Implements…………………………………………………………………………………………. 7-6-1
7-6-2 Quick Coupler…………………………………………………………………………………………………………………………………………. 7-6-9
7-7 Cabin…………………………………………………………………………………………………………………………………………………………….. 7-7-1
7-7-1 Removal and Reinstallation of Cabin …………………………………………………………………………………………………………. 7-7-1
CHAPTER 8
TROUBLESHOOTING
8-1 Non-Breakdowns…………………………………………………………………………………………………………………………………………….. 8-1-1
8-1-1 Natural Release of Bucket………………………………………………………………………………………………………………………… 8-1-1
8-1-2 Discontinuous Arm Movement ………………………………………………………………………………………………………………….. 8-1-1
8-1-3 Drifting of Upperstructure on Quick Travel Operation …………………………………………………………………………………… 8-1-2
8-1-4 Thermal Shock of Travel Motor …………………………………………………………………………………………………………………. 8-1-3
8-1-5 Elongation of Boom Swing Cylinder on 65 degrees Swing ……………………………………………………………………………. 8-1-4
8-1-6 Telescopic Motion of Boom Swing Cylinder with Lock Lever Set to Lock Position ……………………………………………. 8-1-5
8-1-7 Time Lag on Travel Speed Switching…………………………………………………………………………………………………………. 8-1-6
8-1-8 Fluctuation in Oil Level of Hydraulic Oil Tank Due to Temperature Change…………………………………………………….. 8-1-7
8-1-9 Operation of Quick Coupler Cylinder (for Quick Coupler Type) ……………………………………………………………………… 8-1-8
8-2 Quick Reference Table for Troubleshooting………………………………………………………………………………………………………… 8-2-1

This Service Manual is intended for Gehl Z25, Mustang 250Z Excavator so as to give the owner/operator assistance in preparing, adjusting, maintaining and servicing the machine. More importantly, this manual provides an operating plan for safe and proper use of the machine. Major points of safe operation are
detailed in Chapter 2 – Safety. Read and understand the contents of this manual completely and become familiar with the machine before
attempting to operate it..

Throughout this manual, information is introduced by the word NOTE or IMPORTANT. Be sure to read the message carefully and comply with the message. Following this information will improve operating and maintenance efficiency, help to avoid breakdown and damage and extend the service life of the machine.