JLG 400CRT Service Manual

Service & Maintenance Manual

Model

330CRT
400CRT

3121111

August 18, 2004

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 BL OCKING OR OV ERHEAD SL ING,
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, NONFLA MMABLE CLEANING
SOLVENTS.

3121111 – JLG Lift – a

INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

REVISON LOG

Original Issue - April 11, 2000

Revised - December 12, 2000

Revised - September 28, 2001

Revised - October 18, 2002

Revised - April 6, 2004

Revised - August 18, 2004

b – JLG Lift – 3121111

TABLE OF CONTENTS

TABLE OF CONTENTS

SUBJECT - SECTION, PARAGRAPH PAGE NO.

SECTION A - INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONS

A.A General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-a

A.B Hydraulic System Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-a

A.C Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-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 Pressure Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.7 Serial Number Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.8 Limit Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.9 Cylinder Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.10 Major Component Weights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.11 Critical Stability Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

2.11 Steer Cylinder Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

2.12 Oscillation Cylinder Bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2.13 Magnetic Speed Pickup Cleaning Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2.14 Pressure Setting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2.15 Limit Switch Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

2.16 Automatic Choke - Field Adjustment (DF-750) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

2.17 Electronic Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19

2.18 Flash Codes and Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

2.19 Preventive Maintenance and Inspection Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27

SECTION 3 - TROUBLESHOOTING

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

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

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

3121111 – JLG Lift – i

TABLE OF CONTENTS

LIST OF FIGURES

FIGURE NO. TITLE PAGE NO.

1-1. Lubrication Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1-1. Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1-2. Serial Number Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

2-1. Arms and Platform Positioning and Support, Cylinder Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6

2-2. 330CRT Lift Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

2-3. 400CRT LIft Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2-4. Cylinder Barrel Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2-5. Capscrew Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-9

2-6. Cylinder Rod Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

2-7. Tapered Bushing Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

2-8. Rod Seal Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

2-9. Wiper Seal Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

2-10. Installation of Head Seal Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11

2-11. Piston Seal Kit Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2-12. Tapered Bushing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

2-13. Seating the Tapered Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

2-14. Poly-Pak Piston Seal Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

2-15. Rod Assembly Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2-16. Steer Cylinder Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

2-17. Magnetic Speed Pickup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-16

2-18. Magnetic Speed Pickup Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

2-19. Valve Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

2-20. Automatic Choke Adjustment (DF-750) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18

2-21. Analyzer Flow Chart - Sheet 1 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-23

2-22. Analyzer Flow Chart - Sheet 2 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-24

3-1. Electrical Schematic - Sheet 1 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

3-2. Electrical Schematic - Sheet 2 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

3-3. Hydraulic Schematic - Sheet 1 of 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-12

3-4. Hydraulic Schematic - Sheet 2 of 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13

ii – JLG Lift – 3121111

TABLE OF CONTENTS

LIST OF TABLES

TABLE NO. TITLE PAGE NO.

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

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

1-3 Lubrication Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1-4 Cylinder Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1-5 Major Component Weights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1-6 Critical Stability Weights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

2-1 Cylinder Component Torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2-2 Holding Valve Torque Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2-3 Help Messages and Flash Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

2-4 Machine Model Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

2-5 Machine Configuration Programming Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26

2-6 Preventive Maintenance and Safety Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28

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

3121111 – JLG Lift – iii

TABLE OF CONTENTS

iv – JLG Lift – 3121111

SECTION 1 - SPECIFICATIONS

SECTION 1. SPECIFICATIONS

1.1 CAPACITIES

Hydraulic Oil Tank

Approximately 16 U.S. gallons (60.6 liters) w/15% air
space.

Hydraulic System (Including Tank)

Approximately 20 U.S. gallons (75.7 liters)

Fuel Tank

Approximately 13 U.S. gallons (48.8 liters)

Engine Crankcase

Gasoline Engine

3.4 quarts (3.2 liters) w/filter

2.9 quarts (2.7 liters) w/o filter

Diesel Engine

5.4 quarts (5.1 liters) w/filter

4.9 quarts (4.6 liters) w/o filter

Coolant Capacity

Diesel Engine

Manufacturer - Kubota 1105

Low RPM - 1500

High RPM - 3000

Alternator - 40 Amp

Fuel Consumption

Low RPM - 0.93 gph (3.5 lph)

High RPM - 1.7 gph (6.6 lph)

Horsepower - 28 @ 3000 RPM

Drive/Steer System

Toe-In - Adjust to 1/2 inch (12.7 mm) overall

Drive Motor Displacement- 400 cc

Drive Brake - Spring applied, hydraulic release, release
pressure - 300 psi (20.7 bar) max.

Hydraulic Filter - Full flow paper (Cartridge type)

10 Microns Nominal

Tires

Standard 30.4 x 10 loader pneumatic or foam filled

3.5 U.S. gallons (13.2 liters)

1.2 COMPONENT DATA

Gasoline Engine

Manufacturer - Kubota 750 Dual Fuel

Displacement - 750 cc

Low RPM - 2200

High RPM - 3600

Alternator - 40 Amp external

Battery - 85 Amphour, 700 cold cranking amps @ 0° F

Fuel Consumption

Low RPM - 1.3 gph (4.9 lph)

High RPM - 2.4 gph (9 lph)

Horsepower - 24.5 @ 3600 RPM

NOTE: Inflate pneumatic tire to 55 psi (3.8 bar)

1.3 PERFORMANCE DATA

Travel Speed

High drive - 3.5 m.p.h.

Gradeability

35%

Turning Radius (Inside)

7 ft. (2 m)

Lift Speed

L

Table 1-1. Lift Speeds

Model Lift Up (Sec) Lift Down (Sec)

330CRT - DF 26.5 - 28.5 43 - 48

330CRT - Diesel 33 - 35 43 - 48

400CRT - DF 39 - 43 49 - 51

400CRT - Diesel 43 - 47 49 - 51

3121111 – JLG Lift – 1-1

SECTION 1 - SPECIFICATIONS

Platform Capacity - Fixed Platform

330CRT - 1,000 lb. (455 kg)

400 CRT - 800 lb. (365 kg)

Platform Extension Capacity

All Models - 250 lb (120 kg)

Machine Weight

330CRT - Approx. 9,320 lb. (4,228 kg)

440CRT - Approx. 10,070 lb. (4,568 kg)

Machine Height (Fully Extended)

330 CRT - 33 ft. (10 m)

400 CRT - 40 ft. (12 m)

Machine Platform Height (Platform Lowered)

330 CRT - 66.5 in. (1.7 m)

400 CRT - 68.25 in. (1.7 m)

Machine Length

10 ft. 2 in. (3 m)

Machine Width

69 in. (1.8 m)

1.5 LUBRICATION

Ta b l e 1-2. Hydraulic Oil

HYDRAULIC SYSTEM OPERATING

TEMPERATURE RANGE

0 to +23 degrees F

(-18 to -5 degrees C )

0 to +210 degrees F

(-18 to +100 degrees C)

+50 to +210 degrees F

(+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 index
of152.

NOTE: 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.

SAE VISCOSITY GRADE

10W

10W-20,10W-30

20W-20

1.4 TORQUE REQUIREMENTS

All wheel lugs must be torqued at 105 ft lb (142 ft lb) every
50 hours.

Lubrication Specifications

Table 1-3. Lubrication Specifications

KEY SPECIFICATIONS

MPG Multipurpose Grease having a minimum dripping

point of 350 degrees F. Excellent water resistance

and adhesive qualiti es, and being of extreme pres-

sure type. (Timken OK 40 pounds minimum.)

EPGL Extreme Pressure Gear Lube (oi l) meeting API ser-

vice classifica tion 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. A PI service classification GL-3, e .g.

Mobil 424.

1-2 – JLG Lift – 3121111

SECTION 1 - SPECIFICATIONS

4 Extends from

front of machine

Note:
500 Hrs. = 3 months
1000 Hrs. = 6 months
2000 Hrs. = 1 year
4000 Hrs. = 2 years

1

Figure 1-1. Lubrication Diagram

Table 1-4. Lubrication Chart

2

3

INDEX

NO

1 Hydraulic Oil Res ervoir Fill Cap/Drain Pl ug HO - Check HO Le vel

2 Hydraulic Filter Element N/A Initial Change - 50 H ours 250

3 Rail Slides N/A MPG - Brush 100

4 Engine Crankcase Fill Cap/Drain Plug Check Engine Oil Level 10/100

KEY TO LUBRICANTS:

MPG - Multi-purpose Grease

EPGL - Extreme Pressure Gear Lube

HO - Hydraulic Oil (Mobil 424)

TO AVOID PERSONAL INJURY, USE SAFETY PROP FOR ALL
MAINTENANCE REQUIRING PLATFORM TO BE ELEVATED.

NOTE: Be sure to lubricate like items on each side

COMPONENT NUMBER/TYPE LUBE POINTS LUBE METHOD

HO - Change HO

NOTE: Recommended lubricating intervals are based on

machine operations under normal conditions. For
machines used in multi-shift operations and/or
exposed to hostile en viron ments or condi tions, lubr i­cation frequencies must be increased accordingly.

Operate hydraulic functions through one complete
cycle before checking hydraulic oil level in tank. Oil
should be visible in ADD sight window on hydraulic
tank. If oil is not visible, add oil until oil is visible in
both ADD and FULL si ght w indow s on tan k. Do no t
overfill tank.

Any time the pump coupling is removed, coat
splines of coupling with Texaco Code 1912 grease
prior to assembly.

INTERVAL

HOURS

10/500

3121111 – JLG Lift – 1-3

SECTION 1 - SPECIFICATIONS

Figure 1-1. Torque Chart

1-4 – JLG Lift – 3121111

SECTION 1 - SPECIFICATIONS

Serial Number

(Stamped)

Figure 1-2. Serial Number Location

1.6 PRESSURE SETTINGS

Main Relief - 3300 psi ± 50 psi (228 bar ± 3.4 bar)

Steer Relief (Left) - max 2600 psi (179 bar)

Steer Relief (Right) - max 1600 psi (110 bar)

Lift Pressure - 330CRT - 2300 psi (159 bar)

400CRT - 2500 psi (172 bar)

Leveling Jacks Valve (If Equipped) - 1200 psi (83 bar)

1.7 SERIAL NUMBER LOCATIONS

For machine identification, a serial number plate is affixed
to the machine. The plate is located on the left side of the
machine between the fuel tank and the rear wheel. In
addition, should the serial number plate be damaged or
missing, the machine serial number is stamped on the top
of frame between the front wheels.

Serial Number Plate

1.8 LIMIT SWITCHES

The machine is equipped with the following limit switches:

High Drive Speed Cut-Out - High drive speed is cut out
when platform is raised above stowed (fully lowered) posi­tion.

Tilt Alarm - 3° - A horn is sounded and a warning light is
illuminated when the machine is operated on a slope that
exceeds 3° with the platform raised. If the machine is oper­ated on a 3° slope with the platform completely lowered,
only the warning light is illuminated.

Drive Cut-Out (400CRT only) - Drive function is cut-out
when the machine reaches a preset height of 30 ft. (0.8
m).

3121111 – JLG Lift – 1-5

SECTION 1 - SPECIFICATIONS

1.9 CYLINDER SPECIFICATIONS

NOTE: All dimensions are given in inches (in), with the met-

ric equivalent, centimeters (cm), in parentheses.

Table 1-5. Cylinder Specifications

Description Bore Stroke Rod Di a

Lift Cylinder

(330CRT)

Upper Lift Cylinder

(400CRT)

Lower Lift Cylinder

(400CRT)

Lockout Cylinde r
(Oscillating Axle)

Leveling Jack

Cylinder

Steer Cylinder 2.5

4.0

(10.2)

3.0

(7.62)

4.0

(10.2)

3.0

(7.6)

2.0

(5.1)

(6.4)

63.7

(161.8)

58.1

(147.6)

58.1

(147.6)

3.75
(9.5)

14.0

(35.6)

7.1

(18.1)

2.75

(7.0)

2.75

(7.0)

2.75

(7.0)

1.25

(3.2)

1.25

(3.2)

1.25

(3.2)

1.10 MAJOR COMPONENT WEIGHTS

1.11 CRITICAL STABILITY WEIGHTS

DO NOT REPLACE ITEMS CRITICAL TO STABILITY WITH ITEMS
OF DIFFERENT WEIGHT OR SPECIFICATION (FOR EXAMPLE:
FILLED TIRES, ENGINE) DO NOT MODIFY UNIT IN ANY WAY TO
AFFECT STABILITY.

Table 1-7. Critical Stability Weights

Component Lb Kg

Tires (Balasted Only) 246 111

Gas/DF Engine (Dry wit h flywheel and hous-

ing)

Diesel Engine (Dry wi th flywheel and hous-

ing)

136 62

256 116

Table 1-6. Major Component Weights

Component Lb Kg

Fixed Platform 569 258

Platform Extension 230 104

Arm Assembly- 3 30CRT
(Includes Lift Cy linder)

Arm Assembly- 4 00CRT
(Includes Lift Cy linder)

Chassis with Foam Fil led Tires 4980 2259

3200 1452

3900 1769

1-6 – JLG Lift – 3121111

SECTION 2. PROCEDURES

SECTION 2 - PROCEDURES

2.1 GENERAL

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.

2.2 SERVICING 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.

3121111 – JLG Lift – 2-1

SECTION 2 - PROCEDURES

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.

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.

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.

Lubrication and Servicing

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

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.

2-2 – JLG Lift – 3121111

SECTION 2 - PROCEDURES

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.

NOTE: Start-up of hydraulic system with oil temperatures

below -15° F (-26° C). 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 -15° F (-26 ° C).

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

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.

2.4 CYLINDERS - THEORY OF OPERATION

The steer cylinder is of the double acting type. The steer
system incorporates a double acting cylinder. A double
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.

The lift cylinder is a single acting type. It does not require
oil when the cylinder is being retracted. The CRT is a grav­ity down machine.

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.

2.5 VALVES - 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 con-

3121111 – JLG Lift – 2-3

SECTION 2 - PROCEDURES

stant. 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.

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.

2.6 COMPONENT FUNCTIONAL DESCRIPTION

Hydraulic Pump

The machine is equipped with two hydraulic pumps, a
function pump and a drive pump. The function pump is a
two-section gear pump that controls the lift and steer func­tions and provides a maximum output of 7.6 gpm (28.8
lpm). The drive pump is a single-section piston pump that
controls the drive function and provides an output of 22
gpm (83.3 lpm).

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.

2.7 WEAR PADS

Sliding Pads

The original thickness of the sliding pads is 1 inches (25
mm). Replace sliding pads when worn to.875 inches (22
mm).

2.8 CYLINDER CHECKING PROCEDURES

NOTE: Cylinder checks must be performed any time a cylin-

der component is repl ac ed or wh en im pro per system
operation is suspected.

Cylinder w/o Counterbalance Valves - Steer Cylinder

IM P O RTAN T

OPERATE FUNCTIONS FROM GROUND CONTROL STATION
ONLY.

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

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

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

2-4 – JLG Lift – 3121111