JLG 26MRT Service Manual

SERVICE & MAINTENANCE

Model 26MRT

3120892

April 11, 2000

AUSTRALIAN OFFICE	EUROPEAN OFFICE	CORPORATE OFFICE
JLG INDUSTRIES, INC.	JLG INDUSTRIES (EUROPE)	JLG INDUSTRIES, INC.
P.O. Box 5119	Kilmartin Place,	1 JLG Drive
11 Bolwarra Road	Tannochside Park	McConnellsburg, PA.
Port Macquarie, Australia	Uddingston, Scotland, G71 5PH	17233-9533
Telephone: [phone]	Telephone: [phone]	USA
Fax: [phone]	Main Fax: [phone]	Telephone: [phone]
	Parts Fax: [phone]	Fax: [phone]

INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

SECTION A. INTRODUCTION - MAINTENANCE SAFETY

PRECAUTIONS

A.A GENERAL

This section contains the general safety precautions which must be observed during maintenance of the aerial platform. It is of utmost importance that maintenance personnel pay strict attention to these warnings and precautions to avoid possible injury to themselves or others, or damage to the equipment. A maintenance program must be followed to ensure that the machine is safe to operate.

MODIFICATION OF THE MACHINE WITHOUT CERTIFICATION BY A RESPONSIBLE AUTHORITY THAT THE MACHINE IS AT LEAST AS SAFE AS ORIGINALLY MANUFACTURED, IS A SAFETY VIOLATION.

The specific precautions to be observed during maintenance are inserted at the appropriate point in the manual. These precautions are, for the most part, those that apply when servicing hydraulic and larger machine component parts.

Your safety, and that of others, is the first consideration when engaging in the maintenance of equipment. Always be conscious of weight. Never attempt to move heavy parts without the aid of a mechanical device. Do not allow heavy objects to rest in an unstable position. When raising a portion of the equipment, ensure that adequate support is provided.

SINCE THE MACHINE MANUFACTURER HAS NO DIRECT CONTROL OVER THE FIELD INSPECTION AND MAINTENANCE, SAFETY IN THIS AREA RESPONSIBILITY OF THE OWNER/OPERATOR.

A.B HYDRAULIC SYSTEM SAFETY

It should be noted that the machines hydraulic systems operate at extremely high potentially dangerous pressures. Every effort should be made to relieve any system pressure prior to disconnecting or removing any portion of the system.

Relieve system pressure by cycling the applicable control several times with the engine stopped and ignition on, to direct any line pressure back into the reservoir. Pressure feed lines to system components can then be disconnected with minimal fluid loss.

A.C MAINTENANCE

FAILURE TO COMPLY WITH SAFETY PRECAUTIONS LISTED IN THIS SECTION MAY RESULT IN MACHINE DAMAGE, PERSONNEL INJURY OR DEATH AND IS A SAFETY VIOLATION.

•NO SMOKING IS MANDATORY. NEVER REFUEL DURING ELECTRICAL STORMS. ENSURE THAT FUEL CAP IS CLOSED AND SECURE AT ALL OTHER TIMES.

•REMOVE ALL RINGS, WATCHES AND JEWELRY WHEN PERFORMING ANY MAINTENANCE.

•DO NOT WEAR LONG HAIR UNRESTRAINED, OR LOOSE-FITTING CLOTHING AND NECKTIES WHICH ARE APT TO BECOME CAUGHT ON OR ENTANGLED IN EQUIPMENT.

•OBSERVE AND OBEY ALL WARNINGS AND CAUTIONS ON MACHINE AND IN SERVICE MANUAL.

•KEEP OIL, GREASE, WATER, ETC. WIPED FROM STANDING SURFACES AND HAND HOLDS.

•USE CAUTION WHEN CHECKING A HOT, PRESSURIZED COOLANT SYSTEM.

•NEVER WORK UNDER AN ELEVATED BOOM UNTIL BOOM HAS BEEN SAFELY RESTRAINED FROM ANY MOVEMENT BY BLOCKING OR OVERHEAD SLING, OR BOOM SAFETY PROP HAS BEEN ENGAGED.

•BEFORE MAKING ADJUSTMENTS, LUBRICATING OR PERFORMING ANY OTHER MAINTENANCE, SHUT OFF ALL POWER CONTROLS.

•BATTERY SHOULD ALWAYS BE DISCONNECTED DURING REPLACEMENT OF ELECTRICAL COMPONENTS.

•KEEP ALL SUPPORT EQUIPMENT AND ATTACHMENTS STOWED IN THEIR PROPER PLACE.

•USE ONLY APPROVED, NONFLAMMABLE CLEANING SOLVENTS.

3120892

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a

INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

REVISON LOG

Original Issue - April 11, 2000

(This manual split from manual 3120844)

b

– JLG Sizzor –

3120892

TABLE OF CONTENTS

	TABLE OF CONTENTS
SUBJECT - SECTION, PARAGRAPH		PAGE NO.
SECTION	A - INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS
A.A	General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . .a
A.B	Hydraulic System Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . .a
A.C	Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . .a

SECTION 1 - SPECIFICATIONS

1.1 Capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

1.2 Component Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

1.3 Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

1.4 Torque Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.5 Lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.6 Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.7 Pressure Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.8 Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.9 Limit Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.10 Major Component Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.11 Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

SECTION 2 - PROCEDURES

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

2.2 Servicing and Maintenance Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

2.3 Lubrication Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

2.4 Cylinders - Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

2.5 Valves - Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3

2.6 Component Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

2.7 Wear Pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

2.8 Cylinder Checking Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

2.9 Lift Cylinder Removal and Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5

2.10 Lift Cylinder Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5

2.11 Steer Cylinder Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

2.12 Tilt Alarm Switch Adjustment (If Equipped) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

2.13 Limit Switch Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

2.14 Pressure Setting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

2.15 Drive Axle Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14

2.16 Brake Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-23

2.17 Throttle Checks and Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-26

2.18 Control Card Setup and Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-26

2.19 Valve Driver Card Setup Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-29

2.20 Preventive Maintenance and Inspection Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-31

SECTION 3 - TROUBLESHOOTING

3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3.2 Troubleshooting Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3.3 Hydraulic Circuit Checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

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TABLE OF CONTENTS

LIST OF FIGURES

FIGURE NO.

TITLE

PAGE NO.

1-1. Lubrication Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1-2. Serial Number Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

1-3. Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6

2-1. Barrel Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2-2. Cap Screw Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2-3. Rod Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2-4. Tapered Bushing Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2-5. Rod Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7

2-6. Poly-Pak Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2-7. Wiper Seal Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2-8. Head Seal Kit Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2-9. Piston Seal Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2-10. Tapered Bushing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2-11. Rod Assembly Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2-12. Steer Cylinder Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

2-13. Tilt Switch Leveling - Manual Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

2-14. Tilt Switch Leveling - Voltmeter Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

2-15. Valve Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14

2-16. Drive Axle Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16

2-17. Carrier Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-21

2-18. Ring Gear and Pinion Tooth Contact Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-22

2-19. Ring Gear Pattern Interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-23

2-20. Brake Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-25

2-21. ADDCO Adjustments (Gasoline/Dual Fuel Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-27

2-22. ADDCO Adjustments (Diesel Engine). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-28

2-23. Valve Driver Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-29

3-1. Electrical Schematic - Yanmar (Sheet of 1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

3-2. Electrical Schematic - Yanmar (Sheet of 2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11

3-3. Electrical Schematic - Daihatsu (Sheet 1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-12

3-4. Electrical Schematic - Daihatsu (Sheet 2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13

3-5. Hydraulic Schematic (Sheet 1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-14

3-6. Hydraulic Schematic (Sheet 2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15

LIST OF TABLES

TABLE NO.

TITLE

PAGE NO.

1-1 Hydraulic Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1-2 Lubrication Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-3 Cylinder Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-4 Major Component Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-5 Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1-6 Lubrication Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

2-1 Cylinder Component Torque Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2-2 Holding Valve Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2-3 Preventive Maintenance and Safety Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-32

3-1 Elevation System Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

3-2 Chassis Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4

3-3 Hydraulic System Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7

3-4 Electrical System Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8

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SECTION 1 - SPECIFICATIONS

SECTION 1. SPECIFICATIONS

1.1CAPACITIES

Hydraulic Oil Tank

56.8 liters (15.0 gallons)

Hydraulic System (Including Tank)

Approximately 68.1 liters (18.0 gallons)

Fuel Tank

29.5 liters (7.8 gallons)

Drive Axle

6.4liters (3 pints)

1.2COMPONENT DATA

Engine

Daihatsu Gasoline/LP

3 cylinder, liquid-cooled

21 horsepower @ 3,000 rpm Idle - 1,500 rpm

Mid Engine - 2,000 rpm

High Engine - 3,000 rpm

Alternator - 14 Amp

Cooling System Capacity

Engine - 1.8 liters (1.9 quarts)

Crankcase Capacity - 3.0 liters (3.2 quarts)

Yanmar Diesel

3 cylinder, liquid-cooled

22 horsepower @ 3,000 rpm Idle - 1,200 rpm

Mid Engine - 2,000 rpm

High Engine - 3,000 rpm

Alternator - 40 Amp

Cooling System Capacity

0.9 liters (1.0 quarts) - engine

Crankcase Capacity - 2.4 liters (2.5 quarts)

Drive Pump

Closed loop piston type

Output - 56.8 lpm (15 gpm) @ 3,000 rpm

Displacement - 19.0 cm3/rev. (1.16 in.3/rev.)

Lift/Steer Pump

Gear type

Output - 11.7 lpm (3.1 gpm) @ 3,000 rpm.

Displacement - 4.0 cm3/rev. (0.24 in.3/rev.).

Steer/Drive System

Steer (Front) Tires - Dico Multi-Trac C/S 26 x 12.00 - 12 NHS; 6 ply; inflate to 2.8 bar (40 psi).

Toe-In - Adjust to 6.4 mm (.25 in) overall.

Drive (Rear) Tires - Dico Tru-Power TL 26 x 12.00 - 12 NHS; 6 ply; inflate to 2.8 bar (40 psi).

Drive Brake - Mico hydraulic multi-disc.

Drive Motor - Eaton 2000 Series; 131 cm3/rev. (8.0 in.3/ rev.).

Drive Axle - Dana Model 44 rigid semi-float, no spin axle assembly; 5.89 ratio; oil capacity - 1.4 liters (3 pints).

Hydraulic Filter - Inline

Return - Bypass Type

10 Microns Nominal

Platform Size

Standard - 1.4 m x 2.2 m (54 in. x 88 in.)

1.3PERFORMANCE DATA

Travel Speed

Maximum Speed - 7.2 kmh (4.5 mph)

Elevated Speed - 1.1 kmh (0.7 mph)

Gradeability

35%

Turning Radius

Inside - 2.5 m (8 ft. 1 in.)

Outside - 4.7 m (15 ft. 4 in.)

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SECTION 1 - SPECIFICATIONS

Lift		1.5 LUBRICATION
Up - 34-42 seconds

Down - 31-39 seconds

Platform Capacity

Standard - 455 kg (1,000 lb.)

Manual Platform Extension Capacity

115 kg (250 lb.)

Machine Weight

Approximately 2359 kg (5,200 lb.)

Wheelbase

2.0 m (78.0 in.)

Machine Height (Platform Fully Elevated)

7.9 m (26 ft.)

Hydraulic Oil

Table 1-1. Hydraulic Oil

HYDRAULIC SYSTEMOPERATING	SAE VISCOSITY GRADE
TEMPERATURE RANGE
0 to +23 degrees F	10W
(-18 to -5 degrees C)
0 to +210 degrees F	10W-20,10W-30
(-18 to +100 degrees C)
+50 to +210 degrees F	20W-20
(+10 to +100 degrees C)

NOTE: Hydraulic oils must have anti-wear qualities at least to API Service Classification GL-3, and sufficient chemical stability for mobile hydraulic system service. JLG Industries recommends Mobilfluid 424 hydraulic oil, which has an SAE viscosity of 10W-30 and a viscosity index of 152.

Machine Height (Platform Lowered)

2.3 m (89.0 in.)

Platform Railing Height

1.0 m (39.5 in.)

Aside from JLG recommendations, it is not advisable to mix oils of different brands or types, as they may not contain the same required additives or be of comparable viscosities. If use of hydraulic oil other than Mobilfluid 424 is desired, contact JLG Industries for proper recommendations.

Machine Length

2.7 m (105.0 in.)

Machine Width

1.8 m (69.0 in.)

Ground Clearance

14.0 cm (5.5 in.)

Maximum Tire Load

921 kg (2,030 lb.) @ 1.3 bar (19 psi)

1.4TORQUE REQUIREMENTS

All wheel lug nuts should be torqued to 122 Nm (90 ft lb) every 150 hours.

NOTE: When maintenance becomes necessary or a fastener has loosened, refer to the Torque Chart in this section to determine proper torque value.

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Lubrication Specifications

1.6CYLINDER SPECIFICATIONS

Table 1-2. Lubrication Specifications

KEY	SPECIFICATIONS
MPG	Multipurpose Grease having a minimum dripping
	point of 350 degress F. Excellent water resistance
	and adhesive qualities, and being of extreme pres-
	sure type. (Timken OK 40 pounds minimum.)
EPGL	Extreme Pressure Gear Lube (oil) meeting API ser-
	vice classification GL-5 or MIL-Spec MIL-L-2105.
EO	Engine (crankcase) Oil. Gas - API SF/SG class, MIL-
	L-2104. Diesel - API CC/CD class, MIL-L-2104B/
	MIL-L-2104C.
HO	Hydraulic Oil. API service classification GL-3, e.g.
	Mobil 424.

NOTE: All dimensions are given in inches (in), with the metric equivalent, centimeters (cm), given in parentheses.

Table 1-3. Cylinder Specifications

Description	Bore	Stroke	Rod Dia.
Lift Cylinder	4.00	39.75	2.50
	(10.2)	(101.0)	(6.4)
Steer Cylinder	2.00	2.69	1.25
(DoubleRrod)	(5.1)	(6.83)	(3.18)

1.7PRESSURE SETTINGS

Main Relief - 145 bar (2100 psi)

Steer Relief - 103 bar (1500 psi)

Lift Up Relief - 145 bar (2100 psi)

Lift Down Relief - 62 bar (900 psi)

1.8SERIAL NUMBER LOCATIONS

For machine identification, a serial number plate is affixed to the machine. The plate is located on the rear center of the machine frame, just below the middle step of the ladder. In addition, if the serial number plate is damaged or missing, the machine serial number is stamped on the right front frame rail, adjacent to the sizzor arms.

1.9LIMIT SWITCHES

The machine is equipped with the following limit switches:

Tilt Alarm (Optional) - 5° - Illuminates a light on the platform and sounds an alarm when the machine is 5° out of level in any direction.

High Drive Cut-Out - High drive speed is cut out when the platform is raised above the stowed position.

1.10 MAJOR COMPONENT WEIGHTS

Table 1-4. Major Component Weights

Component	lb	kg
Platform	382	173
Manual Platform Extension	221	100
Arm Assembly (Includes Lift Cylinder)	1618	734
Chassis - w/Standard Tires	2979	1351

1.11 CRITICAL STABILITY WEIGHTS

DO NOT REPLACE ITEMS CRITICAL TO STABILITY, SUCH AS ENGINES, AXLES OR TIRES, WITH ITEMS OF DIFFERENT WEIGHT OR SPECIFICATION. DO NOT MODIFY UNIT IN ANY WAY TO AFFECT STABILITY.

Table 1-5. Critical Stability Weights

Component	lb	kg
Tire and Wheel Assembly - Std (each)	50	23
Daihatsu Gasoline/LP Engine	132	60
Yanmar Diesel Engine	183	81
Dana Drive Axle	130	59

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Figure 1-1. Lubrication Diagram

Table 1-6. Lubrication Chart

	INDEX	COMPONENT	NUMBER/TYPE LUBE POINTS	LUBE METHODS	INTERVAL
	NO				HOURS
	1	Wheel Bearings	2- Front Wheels	MPG - repack	1200
	2	Hydraulic Oil	Fill Cap/Drain Plug	HO - Check HO Level	Daily/1200
				HO - Change HO
	3	Hydraulic Return Filter	N/A	N/A	50/300
	4	Charge Pump Filter	N/A	N/A	50/300
	5	Crankcase - Vanguard Gasoline/LP	FillCap/Drain Plug	EO - Check EO Level	Daily/50/300
		Engine		EO - Change EO
	6	Crankcase - Yanmar Diesel Engine	FillCap/Drain Plug	EO - Check EO Level	Daily/50/300
				EO - Change EO
	7	Rear Axle	FillCap/Drain Plug	EPGL - Check EPGL Level	150/1200
				EPGL - Change EPGL

	KEY TO LUBRICANTS:					NOTE: 1. Be sure to lubricate like items on each side.
	EO - Engine Oil					2. Recommended lubricating intervals are based
						on maching operations under normal conditions.
	EPGL - Extreme Pressure Gear Lubricant					For machines used in multi-shift operations and/or
	HO - Hydraulic Oil - Mobilfluid 424					exposed to hostile environments or conditions,
						lubrication frequencies must be increased accord-
	MPG - Multi-purpose Grease					ingly.
						3. Operate hydraulic functions through one com-
						plete cycle before checking hydraulic oil level in
						tank. Oil should be visible in ADD sight window on
	TO AVOID PERSONAL INJURY, USE SAFETY PROP FOR ALL
						hydraulic tank. If oil is not visible, add oil until oil is
	MAINTENANCE REQUIREING PLATFORM TO BE ELEVATED.
						visible in both ADD and FULL sight windows on
						tank. Do not overfill tank.

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Figure 1-2. Serial Number Locations

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Figure 1-3. Torque Chart

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SECTION 2. PROCEDURES

2.1GENERAL

This section provides information necessary to perform maintenance on the scissor lift. Descriptions, techniques and specific procedures are designed to provide the safest and most efficient maintenance for use by personnel responsible for ensuring the correct installation and operation of machine components and systems.

WHEN AN ABNORMAL CONDITION IS NOTED AND PROCEDURES CONTAINED HEREIN DO NOT SPECIFICALLY RELATE TO THE

NOTED IRREGULARITY, WORK SHOULD BE STOPPED AND

TECHNICALLY QUALIFIED GUIDANCE OBTAINED BEFORE WORK IS RESUMED.

The maintenance procedures included consist of servicing and component removal and installation, disassembly and assembly, inspection, lubrication and cleaning. Information on any special tools or test equipment is also provided where applicable.

2.2SERVICING AND MAINTENANCE GUIDELINES

General

The following information is provided to assist you in the use and application of servicing and maintenance procedures contained in this chapter.

Safety and Workmanship

Your safety, and that of others, is the first consideration when engaging in the maintenance of equipment. Always be conscious of weight. Never attempt to move heavy parts without the aid of a mechanical device. Do not allow heavy objects to rest in an unstable position. When raising a portion of the equipment, ensure that adequate support is provided.

Cleanliness

1.The most important single item in preserving the long service life of a machine is to keep dirt and foreign materials out of the vital components. Precautions have been taken to safeguard against this. Shields, covers, seals, and filters are provided to keep air, fuel, and oil supplies clean; however, these items must be maintained on a scheduled basis in order to function properly.

2.At any time when air, fuel, or oil lines are disconnected, clear adjacent areas as well as the openings

and fittings themselves. As soon as a line or component is disconnected, cap or cover all openings to prevent entry of foreign matter.

3.Clean and inspect all parts during servicing or maintenance, and assure that all passages and openings are unobstructed. Cover all parts to keep them clean. Be sure all parts are clean before they are installed. New parts should remain in their containers until they are ready to be used.

Components Removal and Installation

4.Use adjustable lifting devices, whenever possible, if mechanical assistance is required. All slings (chains, cables, etc.) should be parallel to each other and as near perpendicular as possible to top of part being lifted.

5.Should it be necessary to remove a component on an angle, keep in mind that the capacity of an eyebolt or similar bracket lessens, as the angle between the supporting structure and the component becomes less than 90°.

6.If a part resists removal, check to see whether all nuts, bolts, cables, brackets, wiring, etc., have been removed and that no adjacent parts are interfering.

Component Disassembly and Reassembly

When disassembling or reassembling a component, complete the procedural steps in sequence. Do not partially disassemble or assemble one part, then start on another. Always recheck your work to assure that nothing has been overlooked. Do not make any adjustments, other than those recommended, without obtaining proper approval.

Pressure-Fit Parts

When assembling pressure-fit parts, use an “anti-seize” or molybdenum disulfide base compound to lubricate the mating surface.

Bearings

1.When a bearing is removed, cover it to keep out dirt and abrasives. Clean bearings in nonflammable cleaning solvent and allow to drip dry. Compressed air can be used but do not spin the bearing.

2.Discard bearings if the races and balls (or rollers) are pitted, scored, or burned.

3.If a bearing is found to be serviceable, apply a light coat of oil and wrap it in clean (waxed) paper. Do not unwrap reusable or new bearings until they are ready to install.

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4.Lubricate new or used serviceable bearings before installation. When pressing a bearing into a retainer or bore, apply pressure to the outer race. If the bearing is to be installed on a shaft, apply pressure to the inner race.

Lubrication and Servicing

Components and assemblies requiring lubrication and servicing are shown in Section 1.

Gaskets

Check that holes in gaskets align with openings in the mating parts. If it becomes necessary to hand-fabricate a gasket, use gasket material or stock of equivalent material and thickness. Be sure to cut holes in the right location, as blank gaskets can cause serious system damage.

Bolt Usage and Torque Application

1.Use bolts of proper length. A bolt which is too long will bottom before the head is tight against its related part. If a bolt is too short, there will not be enough thread area to engage and hold the part properly. When replacing bolts, use only those having the same specifications of the original, or one which is equivalent.

2.Unless specific torque requirements are given within the text, standard torque values should be used on heat-treated bolts, studs, and steel nuts, in accordance with recommended shop practices.

Hydraulic Lines and Electrical Wiring

Clearly mark or tag hydraulic lines and electrical wiring, as well as their receptacles, when disconnecting or removing them from the unit. This will assure that they are correctly reinstalled.

Hydraulic System

1.Keep the system clean. If evidence of metal or rubber particles is found in the hydraulic system, drain and flush the entire system.

2.Disassemble and reassemble parts on clean work surface. Clean all metal parts with non-flammable cleaning solvent. Lubricate components, as required, to aid assembly.

Lubrication

Service applicable components with the amount, type, and grade of lubricant recommended in this manual, at the specified intervals. When recommended lubricants are not available, consult your local supplier for an equivalent that meets or exceeds the specifications listed.

Batteries

Clean batteries, using a non-metallic brush and a solution of baking soda and water. Rinse with clean water. After cleaning, thoroughly dry batteries and coat terminals with an anti-corrosion compound.

2.3 LUBRICATION INFORMATION

Hydraulic System

1.The primary enemy of a hydraulic system is contamination. Contaminants enter the system by various means, e.g., using inadequate hydraulic oil, allowing moisture, grease, filings, sealing components, sand, etc., to enter when performing maintenance, or by permitting the pump to cavitate due to insufficient system warm-up or leaks in the pump supply (suction) lines.

2.The design and manufacturing tolerances of the component working parts are very close, therefore, even the smallest amount of dirt or foreign matter entering a system can cause wear or damage to the components and generally results in faulty operation. Every precaution must be taken to keep hydraulic oil clean, including reserve oil in storage. Hydraulic system filters should be checked, cleaned, and/or replaced as necessary, at the specified intervals required in the Lubrication Chart in Section 1 and the Preventive Maintenance and Inspection Chart in this section. Always examine filters for evidence of metal particles.

3.Cloudy oils indicate a high moisture content which permits organic growth, resulting in oxidation or corrosion. If this condition occurs, the system must be drained, flushed, and refilled with clean oil.

4.It is not advisable to mix oils of different brands or types, except as recommended, as they may not contain the same required additives or be of comparable viscosities. Good grade mineral oils, with viscosities suited to the ambient temperatures in which the machine is operating, are recommended for use.

NOTE: Metal particles may appear in the oil or filters of new machines due to the wear-in of meshing components.

Hydraulic Oil

1.Refer to Section1 for recommendations for viscosity ranges.

2.JLG recommends Mobilfluid 424, which has an SAE viscosity of 10W-30 and a viscosity index of 152.

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NOTE: Start-up of hydraulic system with oil temperatures below -26° C (-15° F). is not recommended. If it is necessary to start the system in a sub-zero environment, it will be necessary to heat the oil with a low density, 100VAC heater to a minimum temperature of -26° C (-15° F).

3.The only exception to the above is to drain and fill the system with Mobil DTE 11 oil or its equivalent.

This will allow start up at temperatures down to -29° C (-20 ° F). However, use of this oil will give poor performance at temperatures above 49° C (120° F). Systems using DTE 11 oil should not be operated at temperatures above 94°C (200°F). under any condition.

acting cylinder is one that requires oil flow to operate the cylinder rod in both directions. Directing oil (by actuating the corresponding control valve to the piston side of the cylinder) forces the piston to travel toward the rod end of the barrel, extending the cylinder rod (piston attached to rod). When the oil flow is stopped, movement of the rod will stop. By directing oil to the rod side of the cylinder, the piston will be forced in the opposite direction and the cylinder rod will retract.

A holding valve is used in the Lift circuit to prevent retraction of the cylinder rod should a hydraulic line rupture or a leak develop between the cylinder and its related control valve.

Changing Hydraulic Oil

1.Use of any of the recommended crankcase or hydraulic oils eliminates the need for changing the oil on a regular basis. However, filter elements must be changed after the first 50 hours of operation and every 300 hours thereafter. If it is necessary to change the oil, use only those oils meeting or exceeding the specifications appearing in this manual. If unable to obtain the same type of oil supplied with the machine, consult local supplier for assistance in selecting the proper equivalent. Avoid mixing petroleum and synthetic base oils. JLG Industries recommends changing the hydraulic oil every two years.

2.Use every precaution to keep the hydraulic oil clean. If the oil must be poured from the original container into another, be sure to clean all possible contaminants from the service container. Always clean the mesh element of the filter and replace the cartridge any time the system oil is changed.

3.While the unit is shut down, a good preventive maintenance measure is to make a thorough inspection of all hydraulic components, lines, fittings, etc., as well as a functional check of each system, before placing the machine back in service.

Lubrication Specifications

Specified lubricants, as recommended by the component manufacturers, are always the best choice, however, multi-purpose greases usually have the qualities which meet a variety of single purpose grease requirements. Should any question arise regarding the use of greases in maintenance stock, consult your local supplier for evaluation.

2.4CYLINDERS - THEORY OF OPERATION

Cylinders are of the double acting type. The Lift and Steer systems incorporate double acting cylinders. A double

2.5VALVES - THEORY OF OPERATION

Solenoid Control Valves (Bang-Bang)

Control valves used are four-way three-position solenoid valves of the sliding spool design. When a circuit is activated and the control valve solenoid energizes, the spool is shifted and the corresponding work port opens to permit oil flow to the component in the selected circuit, with the opposite work port opening to reservoir. Once the circuit is deactivated (control returned to neutral), the valve spool returns to neutral (center) and oil flow is then directed through the valve body and returns to reservoir. A typical control valve consists of the valve body, sliding spool, and two solenoid assemblies. The spool is machine fitted in the bore of the valve body. Lands on the spool divide the bore into various chambers, which, when the spool is shifted, align with corresponding ports in the valve body open to common flow. At the same time other ports would be blocked to flow. The spool is springloaded to center position, therefore when the control is released, the spool automatically returns to neutral, prohibiting any flow through the circuit.

Proportional Control Valves

The proportional control valves provide a power output matching that required by the load. A small line connected to a load sensing port feeds load pressure back to a sequence valve. The sequence valve senses the difference between the load and pump outlet pressure, and varies the pump displacement to keep the difference constant. This differential pressure is applied across the valve’s meter-in spool, with the effect that pump flow is determined by the degree of spool opening, independent of load pressure. Return lines are connected together, simplifying routing of return flow and to help reduce cavitation. Load sensing lines connect through shuttle valves to feed the highest load signal back to the sequence valve. Integral actuator port relief valves, anti-cavitation check valves, and load check valves are standard.

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Relief Valves

Main relief valves are installed at various points within the hydraulic system to protect associated systems and components against excessive pressure. Excessive pressure can be developed when a cylinder reaches its limit of travel and the flow of pressurized fluid continues from the system control. The relief valve provides an alternate path for the continuing flow from the pump, thus preventing rupture of the cylinder, hydraulic line or fitting. Complete failure of the system pump is also avoided by relieving circuit pressure. The relief valve is installed in the circuit between the pump outlet (pressure line) and the cylinder of the circuit, generally as an integral part of the system valve bank. Relief pressures are set slightly higher than the load requirement, with the valve diverting excess pump delivery back to the reservoir when operating pressure of the component is reached.

Crossover Relief Valves

Crossover relief valves are used in circuits where the actuator requires an operating pressure lower than that supplied to the system. When the circuit is activated and the required pressure at the actuator is developed, the crossover relief diverts excess pump flow to the reservoir. Individual, integral reliefs are provided for each side of the circuit.

2.7WEAR PADS

Sliding Pads

The original thickness of the sliding pads is 51 mm (2 in). Replace sliding pads when worn to 48 mm (1.875 in).

2.8CYLINDER CHECKING PROCEDURES

NOTE: Cylinder checks must be performed any time a cylinder component is replaced or when improper system operation is suspected.

Cylinder w/o Counterbalance Valves - Steer Cylinder

OPERATE FUNCTIONS FROM GROUND CONTROL STATION

ONLY.

DO NOT FULLY EXTEND CYLINDER TO END OF STROKE.

RETRACT CYLINDER SLIGHTLY TO AVOID TRAPPING PRES-

SURE.

1.Using all applicable safety precautions, activate motor and fully extend cylinder to be checked. Shut down motor.

2.6COMPONENT FUNCTIONAL DESCRIPTION

Hydraulic Pump

The machine is equipped with two hydraulic pumps, a function pump and a drive pump. The function pump is a single-section gear pump that controls the lift and steer functions and provides an output of 11.7 lpm (3.1 gpm). The drive pump is a single-section piston pump that controls the drive function and provides an output of 56.8 lpm (15 gpm).

Lift Cylinder Counterbalance/Manual

Descent Valve

The lift cylinder counterbalance/manual descent valve is located on top of the lift cylinder. The counterbalance valve is used to hold the platform in place when raised. A cable is connected to the valve which, when pulled, manually opens the lift down port and allows the platform to be lowered in the event hydraulic power is lost.

2.Carefully disconnect hydraulic hose from retract port of cylinder. There will be initial weeping of hydraulic fluid which can be caught in a suitable container. After the initial discharge, there should be no further leakage from the retract port.

3.Activate motor and activate cylinder extend function. Check retract port for leakage.

4.If cylinder leakage is 6-8 drops per minute or more, piston seals are defective and must be replaced. If cylinder retract port leakage is less than 6-8 drops per minute, carefully reconnect hose to retract port and retract cylinder.

5.With cylinder fully retracted, shut down motor and carefully disconnect hydraulic hose from cylinder extend port.

6.Activate motor and activate cylinder retract function. Check extend port for leakage.

7.If cylinder leakage is 6-8 drops per minute or more, piston seals are defective and must be replaced. If extend port leakage is less than 6-8 drops per minute, carefully reconnect hose to extend port, then activate cylinder through one complete cycle and check for leaks.

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Cylinders w/Single Counterbalance Valves - Lift Cylinder

OPERATE ALL FUNCTIONS FROM GROUND CONTROL STATION

ONLY.

1.Using all applicable safety precautions, activate hydraulic system.

3.Retract the lift cylinder rod completely.

4.Tag and disconnect the hydraulic lines, then cap the lift cylinder hydraulic lines and ports.

5.Remove the bolt and locknut securing the barrel end attach pin to the lower arm assembly. Using a suitable brass drift, drive out the barrel end attach pin from the arm assembly.

6.Carefully remove the cylinder from the scissor lift and place in a suitable work area.

WHEN WORKING ON THE LIFT CYLINDER, RAISE THE PLAT-

FORM COMPLETELY AND SUPPORT THE PLATFORM USING A SUITABLE OVERHEAD LIFTING DEVICE.

DO NOT FULLY EXTEND LIFT CYLINDER TO END OF STROKE. RETRACT CYLINDER SLIGHTLY TO AVOID TRAPPING PRES-

SURE.

2.Raise platform completely then retract cylinder slightly to avoid trapping pressure. Place a suitable overhead lifting device approximately 1 inch (2.5 cm) below the platform.

3.Shut down hydraulic system and allow machine to sit for 10-15 minutes. Carefully remove hydraulic hoses from cylinder port block.

4.There will be initial weeping of hydraulic fluid, which can be caught in a suitable container. After the initial discharge, there should not be any further leakage from the ports. If leakage continues at a rate of 6-8 drops per minute or more, the counterbalance valve is defective and must be replaced.

5.If no repairs are necessary or when repairs have been made, carefully reconnect hydraulic hoses to the appropriate ports.

6.Remove lifting device from platform, activate hydraulic system and run cylinder through one complete cycle to check for leaks.

2.9LIFT CYLINDER REMOVAL AND INSTALLATION

Removal

1.Place the machine on a flat and level surface. Start the motor and raise the platform. Shut down the engine and attach a suitable lifting device to the platform.

2.Remove the bolt and locknut securing the cylinder rod attach pin to the upper inner arm assembly. Using a suitable brass drift, drive out the rod end attach pin from the arm assembly.

Installation

1.Install lift cylinder in place using suitable slings, aligning barrel end attach pin mounting holes on lower arm assembly.

2.Using a suitable drift, drive the barrel end attach pin through the mounting holes in the lift cylinder and the lower arm assembly. Secure in place with the bolt and locknut.

3.Remove cylinder port plugs and hydraulic line caps and correctly attach lines to cylinder ports.

4.Extend the cylinder rod until the attach pin hole aligns with those in the upper arm assembly. Using a suitable drift, drive the cylinder rod attach pin through the aligned holes, taking care to align the pin retaining hole with the hole in arm assembly. Secure the pin in place with the bolt and locknut.

5.Lower platform to stowed position and shut down motor. Check hydraulic fluid level and adjust accordingly.

2.10LIFT CYLINDER REPAIR

Disassembly

DISASSEMBLY OF THE CYLINDER SHOULD BE PERFORMED ON A CLEAN WORK SURFACE IN A DIRT FREE WORK AREA.

1.Connect a suitable auxiliary hydraulic power source to the cylinder port block fitting.

DO NOT FULLY EXTEND CYLINDER TO END OF STROKE. RETRACT CYLINDER SLIGHTLY TO AVOID TRAPPING PRESSURE.

2.Operate the hydraulic power source and extend the cylinder. Shut down and disconnect the power source. Adequately support the cylinder rod, if necessary.

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3.If applicable, remove the cartridge-type holding valve and fittings from the cylinder port block. Discard o-rings.

4.Place the cylinder barrel into a suitable holding fixture.

8.With the barrel clamped securely, apply pressure to the rod pulling device and carefully withdraw the complete rod assembly from the cylinder barrel.

Figure 2-1. Barrel Support

5.To aid in realignment, mark cylinder head and barrel with a center punch. Using an allen wrench, loosen the eight (8) cylinder head retainer cap screws and remove cap screws from cylinder barrel.

Figure 2-3. Rod Support

9.Using suitable protection, clamp the cylinder rod in a vise or similar holding fixture as close to the piston as possible.

10.If applicable, loosen and remove the nut which attaches the piston to the rod, then remove the piston from the rod.

11.If applicable, loosen and remove the cap screw(s) securing the tapered bushing to the piston.

12.Insert the capscrew(s) in the threaded holes in the outer piece of the tapered bushing. Progressively tighten the cap screw(s) until the bushing is loose on the piston, then remove the bushing from the piston.

Figure 2-2. Cap Screw Removal

6.If applicable, using a suitable spanner wrench, loosen the spanner nut retainer and remove the spanner nut from the cylinder barrel.

7.Attach a suitable pulling device to the cylinder rod port block or cylinder rod end, as applicable.

EXTREME CARE SHOULD BE TAKEN WHEN REMOVING THE CYLINDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD

OFF-CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON

AND CYLINDER BARREL SURFACES.

Figure 2-4. Tapered Bushing Removal

13.Screw the piston counter-clockwise, by hand, and remove the piston from the cylinder rod.

14.Remove and discard the piston o-rings, back-up rings, guidelock rings and hydrolock seals.

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15.If applicable, remove the piston spacer from the rod.

16.Remove the rod from the holding fixture. Remove the cylinder head and retainer plate from the rod.

Cleaning and Inspection

1.Clean all parts thoroughly in an approved cleaning solvent.

2.Inspect the cylinder rod for scoring, tapering, ovality, or other damage. If necessary, dress rod with Scotch Brite or equivalent. Replace rod if necessary.

3.Inspect threaded portion of rod for damage. Dress threads as necessary.

4.Inspect inner surface of cylinder barrel tube for scoring or other damage. Check inside diameter for tapering or ovality. Replace if necessary.

5.Inspect threaded portion of barrel for damage. Dress threads as necessary.

6.Inspect piston surface for damage and scoring and for distortion. Dress piston surface or replace piston as necessary.

7.Inspect threaded portion of piston for damage. dress threads as necessary.

8.Inspect seal and o-ring grooves in piston for burrs and sharp edges. Dress applicable surfaces as necessary.

9.Inspect cylinder head inside diameter for scoring or other damage and for ovality and tapering. Replace as necessary.

10.Inspect threaded portion of head for damage. Dress threads as necessary.

11.Inspect seal and o-ring grooves in head for burrs and sharp edges. Dress applicable surfaces as necessary.

12.Inspect cylinder head outside diameter for scoring or other damage and ovality and tapering. Replace as necessary.

13.If applicable, inspect rod and barrel bearings for signs of correct lubrication and excessive wear. If necessary, replace bearings as follows:

a.Thoroughly clean steel bushing hole of burrs, dirt, etc. to facilitate bearing installation.

b.Inspect steel bushing for wear or other damage. If steel bushing is worn or damaged, rod or barrel (as applicable) must be replaced.

c.Lubricate inside of steel bushing with WD-40 prior to bearing installation.

d.Using arbor of the correct size, carefully press the bearing into the steel bushing.

NOTE: Install the cylinder pin into the Gar-Max bearing dry. Lubrication is not required with chrome pins and bearings.

14.Inspect travel limiting collar or spacer for burrs and sharp edges. If necessary, dress inside diameter surface with Scotch Brite or equivalent.

15.If applicable, inspect port block fittings and holding valve. Replace as necessary.

16.Inspect the oil ports for blockage or the presence of dirt or other foreign material. Repair as necessary.

17.If applicable, inspect piston rings for cracks or other damage. Replace as necessary.

Assembly

NOTE: Prior to cylinder assembly, ensure that the proper cylinder seal kit is used.

Apply a light film of hydraulic oil to all components prior to assembly.

1.Using a special tool, pictured in the following illustration, install a new rod seal into the applicable cylinder head gland groove. Refer to the following illustration for the proper tool size.

Figure 2-5. Rod Seal Installation

WHEN INSTALLING NEW “POLY-PAK” TYPE PISTON SEALS,

ENSURE SEALS ARE INSTALLED PROPERLY. REFER TO FIGURE

2-9., PISTON SEAL KIT FOR CORRECT SEAL ORIENTATION. IMPROPER SEAL INSTALLATION COULD RESULT IN CYLINDER LEAKAGE AND IMPROPER CYLINDER OPERATION.

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