Jlg 120HX ANSI Service Manual User Manual

Service and Maintenance ManualModel120HXP/N - 3120686April 6, 2009

vi – JLG Lift – 3120686TABLE OF CONTENTS (Continued) This page left blank intentionally.

SECTION 3 - TROUBLESHOOTING3-18 – JLG Lift – 3120686Pump not delivering oil.Restricted suction line. Clean, repair, or replace line.Air entering syste

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-19Damaged wiring on control switch or auxiliary pump.See proper wiring diagram.Control switch not fu

SECTION 3 - TROUBLESHOOTING3-20 – JLG Lift – 3120686.Table 3-6.Electrical System - TroubleshootingTROUBLE PROBABLE CAUSE REMEDYPLATFORM CONTROLS.No po

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-21INSTRUMENTS AND INDICATORS.Travel warning horn inoperative.Circuit breaker open. Determine and cor

SECTION 3 - TROUBLESHOOTING3-22 – JLG Lift – 3120686Figure 3-1. Electrical Diagram - Boom Length Indicator

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-23This page left blank intentionally.

SECTION 3 - TROUBLESHOOTING3-24 – JLG Lift – 3120686Figure 3-2. Electrical Schematic - Sheet 1 of 4

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-25Figure 3-3. Electrical Schematic - Sheet 2 of 41870023B

SECTION 3 - TROUBLESHOOTING3-26 – JLG Lift – 3120686Figure 3-4. Electrical Schematic - Sheet 3 of 4

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-27Figure 3-5. Electrical Schematic - Sheet 4 of 41870023B

SECTION 1 - SPECIFICATIONS3120686 – JLG Lift – 1-1SECTION 1. SPECIFICATIONS1.1 CAPACITIESFuel Tank26 gallons (98 liters).Hydraulic Oil Tank50 gallons

SECTION 3 - TROUBLESHOOTING3-28 – JLG Lift – 3120686Figure 3-6. Hydraulic Schematic - (Sheet 1 of 2)

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-292792377AFigure 3-7. Hydraulic Schematic - (Sheet 2 of 2)

SECTION 3 - TROUBLESHOOTING3-30 – JLG Lift – 3120686This page left blank intentionally.

Corporate OfficeJLG Industries, Inc.1 JLG DriveMcConnellsburg PA. 17233-9533USA (717) 485-5161 (717) 485-6417JLG Worldwide LocationsJLG Industries (Au

SECTION 1 - SPECIFICATIONS1-2 – JLG Lift – 3120686Turning Radius (4 Wheel Steer)Outside.19 ft. 3 in. (5.86 m) w/axles extended.18 ft. 0 in. (5.48 m) w

SECTION 1 - SPECIFICATIONS3120686 – JLG Lift – 1-31.5 FUNCTION SPEEDS (MACHINES BUILT AFTER S/N 38697)Te l es co p eExtend - 80-100 seconds.Retract -

SECTION 1 - SPECIFICATIONS1-4 – JLG Lift – 3120686Figure 1-1. Torque Chart

SECTION 1 - SPECIFICATIONS3120686 – JLG Lift – 1-51.7 LUBRICATIONEngine (Crankcase) OilNOTE: Crankcase oil must be a high quality detergent type meeti

SECTION 1 - SPECIFICATIONS1-6 – JLG Lift – 3120686Figure 1-2. Lubrication Diagram

SECTION 1 - SPECIFICATIONS3120686 – JLG Lift – 1-7Table 1-6. Lubrication ChartIndexNo.ComponentNumber/TypeLube PointsLube &MethodIntervalHoursComm

SECTION 1 - SPECIFICATIONS1-8 – JLG Lift – 31206861.8 PRESSURE SETTINGS - PSI (BAR)NOTE: All pressures are given in pounds per square inch (psi), with

SECTION 1 - SPECIFICATIONS3120686 – JLG Lift – 1-91.9 SERIAL NUMBER LOCATIONSFor machine identification, a serial number plate is affixed to the machi

SECTION 1 - SPECIFICATIONS1-10 – JLG Lift – 31206861.13 CRITICAL STABILITY WEIGHTSDO NOT REPLACE ITEMS CRITICAL TO STABILITY, SUCH AS THE COUNTERWEIGH

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-1SECTION 2. PROCEDURES2.1 GENERALThis section provides information necessary to perform maintenance on t

SECTION 2 - PROCEDURES2-2 – JLG Lift – 31206863. If bearing is found to be serviceable, apply a light coat of oil and wrap it in clean (waxed) paper.

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-3Hydraulic Oil1. Refer to Table 1-1 for recommendations for viscosity ranges.2. JLG recommends Kendall Hy

SECTION 2 - PROCEDURES2-4 – JLG Lift – 3120686Manual Hydraulic Control ValvesThe manual hydraulic control valves consist of four-way, multi-position v

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-5Figure 2-1. Boom Chain Adjustments

SECTION 2 - PROCEDURES2-6 – JLG Lift – 3120686An immediate disassembly of the boom assembly and inspection of the boom chains and related components i

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-7b. Lubrication: One of the most important but often overlooked factors is adequate lubrication. In addit

SECTION 2 - PROCEDURES2-8 – JLG Lift – 3120686ened metals liberate hydrogen which attacks and weakens the metal grain structure.h. Chain Anchors and S

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-9replacement, or cylinder rod is scored and cylinder requires overhaul or replacement. If boom has retrac

INTRODUCTION3120686 – JLG Lift – A-1SECTION A. INTRODUCTION - MAINTENANCE SAFETY PRECAUTIONSA GENERALThis section contains the general safety precaut

SECTION 2 - PROCEDURES2-10 – JLG Lift – 3120686Cylinders w/Single Counterbalance Valves - Lift Cylinder, Telescope Cylinder, Extend-A-Reach Cylinder.O

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-112.10 CYLINDER REMOVAL AND INSTALLATIONTelescope Cylinder Removal1. Place machine on a flat and level su

SECTION 2 - PROCEDURES2-12 – JLG Lift – 31206867. Install the two (2) extension chain adjusting nuts at the aft end of the base boom.8. Install the ro

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-13Master Level Cylinder Removal1. With the main boom positioned to horizontal and properly supported, pre

SECTION 2 - PROCEDURES2-14 – JLG Lift – 31206863. If applicable, remove the cartridge-type holding valve and fittings from the cylinder port block. Di

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-156. Inspect piston surface for damage and scoring and for distortion. Dress piston surface or replace pi

SECTION 2 - PROCEDURES2-16 – JLG Lift – 3120686NOTE: Self-locking setscrews used on piston nuts should be discarded and replaced whenever they are rem

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-17the bleeder port unplugged, venting all trapped air to atmosphere. A suitable hose may be attached to t

SECTION 2 - PROCEDURES2-18 – JLG Lift – 312068617145121616166Figure 2-6. Boom Assembly - Sheet 1 of 2

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-1971818432189151510111. Boom Base2. Inner Mid Boom3. Outer Mid Boom4. Fly Boom5. Telescope Cylinder6. Out

INTRODUCTIONA-2 – JLG Lift – 3120686REVISON LOGJuly 1, 1992 - Original IssueJune 1, 1995 - RevisedJanuary, 1999 - RevisedAugust 9, 2001 - RevisedMay 1

SECTION 2 - PROCEDURES2-20 – JLG Lift – 312068618. Carefully lift inner mid, outer mid and fly sections clear of base section and lower to a suitably

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-21Inspection1. Inspect all sheaves (extend chains, retract chains and telescope cylinder) for excessive g

SECTION 2 - PROCEDURES2-22 – JLG Lift – 312068616. Using lightweight motor oil (SAE 20W), adequately lubricate portion of chain occupying cylinder cha

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-232. Insert boom pivot pin, ensuring that locating slots in pin are aligned with setscrew locating holes

SECTION 2 - PROCEDURES2-24 – JLG Lift – 31206862.13 TILT ALARM SWITCHPERFORM TILT ALARM SWITCH LEVELING PROCEDURE A MINI-MUM OF EVERY SIX MONTHS TO EN

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-25flange nuts have been tightened too far. Loosen the “X” nut and repeat steps (3) through (7).Voltmeter

SECTION 2 - PROCEDURES2-26 – JLG Lift – 3120686ACTUATOR CABLEADECO ACTUATORLOW ENGINEHIGH ENGINE LIMIT SWITCHSLIDE PIN (2)SLIDE PIN (1)LIMIT SWITCHTHR

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-27b. Bottom out Extend-A-Reach Up function.c. Loosen nut at extend-a-reach up relief and adjust pressure

SECTION 2 - PROCEDURES2-28 – JLG Lift – 3120686Figure 2-11. Pressure Setting Adjustments - Main Valve - Machines Built Before S/N 38697

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-29Figure 2-12. Pressure Setting Adjustments - Frame Valve - Machines Built Before S/N 38697

3120686 – JLG Lift – i TABLE OF CONTENTSTABLE OF CONTENTSSUBJECT - SECTION, PARAGRAPH PAGE NO.SECTION A - INTRODUCTION - MAINTENANCE SA

SECTION 2 - PROCEDURES2-30 – JLG Lift – 3120686Figure 2-13. Pressure Setting Adjustments - Main Valve - Machines Built After S/N 38697

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-31Figure 2-14. Pressure Setting Adjustments - Frame Valve - Machines Built After S/N 38697

SECTION 2 - PROCEDURES2-32 – JLG Lift – 3120686k. Bottom out Rear Axle Retract function.l. Loosen nut on rear axle retract relief and adjust pressure

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-33Wear Tolerance1. From the underside of the machine, at rear center, with the boom fully elevated and fu

SECTION 2 - PROCEDURES2-34 – JLG Lift – 3120686d. Tag and disconnect the hydraulic lines from the fittings on the top and sides of the rotary cou-plin

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-35IF COMPRESSED AIR OR ELECTRICALLY-OPERATED IMPACT WRENCH IS USED FOR TIGHTENING THE BEARING ATTACH-MENT

SECTION 2 - PROCEDURES2-36 – JLG Lift – 3120686Figure 2-19. Drive Torque Hub

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-37b. Remove two bolts (303) securing cover cap (306) to cover and remove cap.c. Remove disconnect rod (30

SECTION 2 - PROCEDURES2-38 – JLG Lift – 3120686Assembly1. If necessary, assemble the hub/spindle assembly (1) as follows:a. With large open end of hub

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-39k. Slide planet shaft through carrier and cluster gear from bottom side. Slot in planet shaft must line

ii – JLG Lift – 3120686TABLE OF CONTENTS (Continued) TABLE OF CONTENTS (continued)SUBJECT - SECTION, PARAGRAPH PAGE NO.Lubrication Specification

SECTION 2 - PROCEDURES2-40 – JLG Lift – 31206862.19 SWING TORQUE HUBDisassembly1. Remove oil plugs (25 and 26) and drain oil from unit into a suitable

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-41Figure 2-20. Swing Torque Hub

SECTION 2 - PROCEDURES2-42 – JLG Lift – 3120686a. Using a suitable hydraulic press, install bearing cups (23 and 27) into hub (24).b. Using the hydrau

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-4318. Position outer thrust washer (8), thrust bearing (9) and thrust washer (8) in cover (1).19. Positio

SECTION 2 - PROCEDURES2-44 – JLG Lift – 3120686Figure 2-21. Swing Brake

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-457. Place a new friction disc (12) on shaft (10) until it contacts return plate (14).8. Add additional n

SECTION 2 - PROCEDURES2-46 – JLG Lift – 3120686Figure 2-22. Drive Brake, Mico

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-475. Insert dowel pins (17), spring retainer (16) and springs (5 and 6) in housing. Insert the springs as

SECTION 2 - PROCEDURES2-48 – JLG Lift – 31206862.23 PQ CONTROLLERSNOTE: The following procedures are to be used as a begin-ning basis for controller a

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-4910. Place the creep toggle switch in the off position.11. Using correct size common blade screwdriver,

3120686 – JLG Lift – iii TABLE OF CONTENTSTABLE OF CONTENTS (continued)SUBJECT - SECTION, PARAGRAPH PAGE NO.2.10 Cylinder Removal and In

SECTION 2 - PROCEDURES2-50 – JLG Lift – 31206867. Check the mA reading in the opposite direction.8. Operate the controller until 1/2 of the slide lock

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-51RAMP AdjustmentControllers equipped with the RAMP feature actually com-pensate for abrupt control handl

SECTION 2 - PROCEDURES2-52 – JLG Lift – 31206862.24 BOOM MARKING TAPE INSTALLATIONBoom marking tape installation is shown in Figure 2-24.2.25 BOOM LEN

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-535. Telescope the boom until the leading edge of the red marking tape is exposed from the mid boom. Adju

SECTION 2 - PROCEDURES2-54 – JLG Lift – 3120686This circuit card operates as follows:A calibrated dc voltage representing the boom angle is sent from

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-55Immediately beyond this point of balance the turntable is permitted to pivot a maximum vertical distanc

SECTION 2 - PROCEDURES2-56 – JLG Lift – 3120686Figure 2-27. Boom Length/Angle Sensor ConfigurationFigure 2-28. Load Radius Circuit Card

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-57TESTSWITCHRESETSWITCH2Figure 2-26. Load Moment Limiting System Monitoring Circuit

SECTION 2 - PROCEDURES2-58 – JLG Lift – 31206869. If boom does not stop at white tape or boom can be extended after being retracted 10 feet (3 meters)

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-592.30 PREVENTIVE MAINTENANCE AND INSPECTION SCHEDULEThe preventive maintenance and inspection checks are

iv – JLG Lift – 3120686TABLE OF CONTENTS (Continued) TABLE OF CONTENTS (continued)SUBJECT - SECTION, PARAGRAPH PAGE NO.2.24 Boom Marking Tape In

SECTION 2 - PROCEDURES2-60 – JLG Lift – 312068611. Check for proper operation while engine is running.12. Check for proper lubrication.13. Check for e

SECTION 2 - PROCEDURES3120686 – JLG Lift – 2-61TURNTABLE1.Engine Oil (see mfg. manual)352.Battery353.Radiator3, 54.Air Cleaner1145.Exhaust System11,57

SECTION 2 - PROCEDURES2-62 – JLG Lift – 3120686CHASSIS1.Wheel and Tire Assembly18,9,152.Drive Motors1,5,63.Drive Torque Hubs1,5,6 3 104.Drive Brakes1,

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-1SECTION 3. TROUBLESHOOTING3.1 GENERALThis section contains troubleshooting information to be used

SECTION 3 - TROUBLESHOOTING3-2 – JLG Lift – 3120686.Table 3-1.Platform Assembly - TroubleshootingTROUBLE PROBABLE CAUSE REMEDYAutomatic leveling inope

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-3.Table 3-2.Boom Assembly - TroubleshootingTROUBLE PROBABLE CAUSE REMEDYCONTROL VALVESValve spool st

SECTION 3 - TROUBLESHOOTING3-4 – JLG Lift – 3120686Fuse is blown out on control card. Replace fuse.Control valve not functioning properly. Repair or r

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-5Function Speed, Drive Speed and High Engine does not operate below horizontal.Damaged wiring on lev

SECTION 3 - TROUBLESHOOTING3-6 – JLG Lift – 3120686Boom extends and retracts erratically.Hydraulic system oil low. Replenish oil as necessary.Wear pad

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-7Boom leaks down.Holding valve sticking. Replace holding valve.Damaged cylinder. Repair or replace c

3120686 – JLG Lift – v TABLE OF CONTENTSLIST OF FIGURES (continued)FIGURE NO. TITLE PAGE NO.2-24. Boom Marking Tape Installation . . . .

SECTION 3 - TROUBLESHOOTING3-8 – JLG Lift – 3120686TOWER LIFT AND UPRIGHT CIRCUIT (A MODELSNo response to control.Function not activated within 7 seco

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-9Counterbalance valve on tower lift cylinder improperly adjusted or not functioning properly.Replace

SECTION 3 - TROUBLESHOOTING3-10 – JLG Lift – 3120686.Table 3-3.Turntable Assembly - TroubleshootingTROUBLE PROBABLE CAUSE REMEDYCONTROL VALVE.Valve Sp

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-11.Table 3-4.Chassis Assembly - TroubleshootingTROUBLE PROBABLE CAUSE REMEDYPOWER PLANT.Engine will

SECTION 3 - TROUBLESHOOTING3-12 – JLG Lift – 3120686Engine worn badly. Rebuild engine.Engine improperly timed. Time engine.Engine overheating. Determi

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-13Drive wheel tire treads worn smooth. Replace tires as necessary and inflate to speci-fied pressure

SECTION 3 - TROUBLESHOOTING3-14 – JLG Lift – 3120686Motor turns slowly in the direction of the last com-mand.Valve not returning to neutral. Check neu

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-15If equipped, swivel coupling leaking internally. (Seals defective.)Repair or replace coupling.Stee

SECTION 3 - TROUBLESHOOTING3-16 – JLG Lift – 3120686Machine wanders; steering not firm.Crossover relief valve set too low or not function-ing properly

SECTION 3 - TROUBLESHOOTING3120686 – JLG Lift – 3-17.Table 3-5.Hydraulic System - TroubleshootingTROUBLE PROBABLE CAUSE REMEDYHYDRAULIC SYSTEMS - GENE