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MAINTENANCE LIFT Maintenance Manual
Manufactured by
TISl:D TE co EQUIPMENT LLCCoral Springs, Florida
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2-ContentsPage 1
Page
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
TABLE OF CONTENTS
CHAPTER 2: MAINTENANCE
Section 1: ServicingPERIODIC MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
HYDRAULIC OIL RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
CHECKING HYDRAULIC OIL LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
FILLING HYDRAULIC OIL RESERVOIR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
LUBRICATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Grease Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Oil Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Section 2: Hydraulic System AdjustmentsHYDRAULIC ADJUSTMENTS - HYDRAULIC POWER MODULE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
HYDRAULIC ADJUSTMENTS - TRAVERSING PLATFORM VALVE. . . . . . . . . . . . . . . . . . . . . . . . . . 4
Flow Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
COUNTER BALANCE/HOLDING VALVE-HOLD PRESSURE ADJUSTMENT . . . . . . . . . . . . . . . . . . 5
LIFT DOWN FLOW CONTROL VALVE ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Section 3: TroubleshootingGENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
HYDRAULIC SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
ELECTRICAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Troubleshooting Chart - General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Section 4: RepairsINTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
STRUCTURAL REPAIRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Scissor arms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Scissor frame or van body. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Handrails . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Surface rust or scratches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Section 5: System SchematicsHYDRAULIC SCHEMATIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
4 Stabilizers & 12VDC Pump with Return Filter . . . . . . . . . . . . . . . . . . . . . . . . . Figure 1 . . . . 1
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2-ContentsPage 2
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
ELECTRICAL SCHEMATIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
How to Read This Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2 . . . . . 1Electrical Schematic, Engine & Chassis - Sheet 1 of 9 . . . . . . . . . . . . . . . . . . . . Figure 3 . . . . . 1Electrical Schematic, Lighting - Sheet 2 of 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 4 . . . . . 1Electrical Schematic, Lift & Stab. Control - Sheet 3 of 9 . . . . . . . . . . . . . . . . . . . Figure 5 . . . . . 1Electrical Schematic, Lift & Stab. Control - Sheet 4 of 9 . . . . . . . . . . . . . . . . . . . Figure 6 . . . . . 1Electrical Schematic, Options - Sheet 5 of 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 7 . . . . . 1Electrical Schematic, Options - Sheet 6 of 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 8 . . . . . 1Electrical Schematic, Options - Sheet 7 of 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 9 . . . . . 1Electrical Schematic, Tables of Veh. Connections - Sheet 8 of 9 . . . . . . . . . . . . Figure 10 . . . . 1Electrical Schematic, Tables of Veh. Connections
DPDT & SPDT Relay Wiring - Sheet 9 of 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 11 . . . . 1
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2-FiguresPage 1
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
LIST OF FIGURES
CHAPTER 2: MAINTENANCE
Section 1: Servicing
2-1 Figure 1 HYDRAULIC OIL FILL POINT......................................................................... Page 3
2-1 Figure 2 GREASE POINTS DIAGRAM ......................................................................... Page 5
2-1 Figure 3 GREASE POINTS - LIFT CYLINDERS UPPER.............................................. Page 6
2-1 Figure 4 GREASE POINTS - LIFT CYLINDERS BOTTOM........................................... Page 7
2-1 Figure 5 GREASE POINTS - STABILIZERS................................................................. Page 7
2-1 Figure 6 GREASE POINTS - TRAVERSING CYLINDER AND ROLLERS................... Page 8
2-1 Figure 7 GREASE POINTS - SCISSOR ROLLERS AND PINS.................................... Page 9
2-1 Figure 8 GREASE POINT - LOWER BOOSTER ARM.................................................. Page 10
2-1 Figure 9 GREASE POINTS - TRACKS AND BOOSTER ARM UPPER LIP ................. Page 10
2-1 Figure 10 OIL POINTS .................................................................................................... Page 11
Section 2: Hydraulic System Adjustments
2-2 Figure 1 HYDRAULIC SYSTEM.................................................................................... Page 3
2-2 Figure 2 TRAVERSING PLATFORM VALVE................................................................ Page 4
2-2 Figure 3 COUNTER BALANCE/HOLDING VALVE....................................................... Page 5
2-2 Figure 4 LIFT DOWN FLOW CONTROL VALVE ADJUSTMENT................................. Page 6
Section 3: Troubleshooting
Section 4: Repairs
Section 5: System Schematics
2-5 Figure 1 HYDRAULIC SCHEMATIC - 4 STABILIZERS & 12V PUMPWITH RETURN FILTER.................................................................................. Page 2
2-5 Figure 2 HOW TO READ THIS SCHEMATIC ............................................................... Page 5
2-5 Figure 3 ELECTRICAL SCHEMATIC, ENGINE & CHASSIS - SHEET 1 OF 9 ............. Page 6
2-5 Figure 4 ELECTRICAL SCHEMATIC, LIGHTING - SHEET 2 OF 9 .............................. Page 7
2-5 Figure 5 ELECTRICAL SCHEMATIC, LIFT & STAB. CONTROL - SHEET 3 OF 9 ...... Page 8
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2-FiguresPage 2
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
2-5 Figure 6 ELECTRICAL SCHEMATIC, LIFT & STAB. CONTROL - SHEET 4 OF 9 ...... Page 9
2-5 Figure 7 ELECTRICAL SCHEMATIC, OPTIONS - SHEET 5 OF 9............................... Page 10
2-5 Figure 8 ELECTRICAL SCHEMATIC, OPTIONS - SHEET 6 OF 9............................... Page 11
2-5 Figure 9 ELECTRICAL SCHEMATIC, OPTIONS - SHEET 7 OF 9............................... Page 12
2-5 Figure 10 ELECTRICAL SCHEMATIC, TABLES OF VEH. CONNECTIONS - SHEET 8 OF 9 ............................................................................................. Page 13
2-5 Figure 11 ELECTRICAL SCHEMATIC, TABLES OF VEH. CONNECTIONS DPDT & SPDT RELAY WIRING - SHEET 9 OF 9 ........................................... Page 14
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SERVICING 2-1Page 1
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
CHAPTER 2: MAINTENANCE
Section 1: Servicing
1. PERIODIC MAINTENANCE
Regular maintenance is required to ensure optimum performance and long life for machine components.Maintain the unit by performing periodic maintenance at the intervals listed in the Periodic MaintenanceChart below.
If the unit is being operated in severe weather conditions such as extreme heat or cold, or in sandy,dusty, or snowy areas, increase the frequency of periodic maintenance as necessary.
NOTE: Refer to the chassis manufacturer’s manual for service requirements to the chassis.
PERIODIC MAINTENANCE CHART
PROCEDUREPERIOD (HOURS)
8 250 OTHER
Perform walk-around inspection and check for damage, missing parts and fluid leaks.
X
Check spotlights, indicator lights, and beacon lights. X
Check hydraulic oil level. X
Check condition of all handrails and mounting brackets. X
Check condition of operator’s boarding steps. X
Check fire extinguisher levels. Make sure they are secured in their mounting brackets.
X
Inspect pivot pins on platform cylinders for wear. X
Check scissors pivot pins and rollers for wear. X
Inspect condition of all hydraulic hoses and fittings and check for leakage.
X
Inspect all hydraulic components for fluid leakage. X
Inspect all wiring harnesses for damage and security. X
Check condition of bumpers. X
Check operation of the platform mounted pendant control station. X
Check condition of Hi-Lift/scissors structure. Check for stress cracks, physical damage, or corrosion.
X
Check platform under structure for cracked welds or corrosion. X
Check condition of placards and safety warning decals. X
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MAINTENANCE2-1Page 2
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
CAUTION
AFTER PERFORMING MAINTENANCE ON THE HI-LIFT, DISPOSE OF ANY ENVIRONMENTALLY SENSITIVE MATERIALS ACCORDING TO LOCAL ENVIRONMENTAL REGULATIONS. EXAMPLES OF SUCH MATERIALS INCLUDE: BATTERIES, RUBBER BELTS, LUBRICANTS (MOTOR OILS AND GREASE), AND HYDRAULIC OIL.
2. HYDRAULIC OIL RECOMMENDATIONS
The hydraulic oil reservoir is factory filled with ISO 15 hydraulic oil at the time of shipping.
SEVERE CLIMATE OPERATION
• If platform lowering becomes too slow in severe cold weather operations, a lower viscosity fluid may be substituted.
3. CHECKING HYDRAULIC OIL LEVEL
Maintaining proper hydraulic oil level is important. DO NOT overfill the hydraulic oil reservoir. Hydraulicoil expands when heated.
1. The hydraulic oil reservoir is equipped with a sight gauge. Ensure that the Hi-Lift is fully lowered and stabilizers must be in stowed position when checking hydraulic oil level using the sight gauge. The oil level should be near the “High” mark and must not be below the “Low” mark.
Replace return filter 6 mos.
Check that all wiring terminals are secure. 6 mos.
Replace corrosion inhibitor in main electrical control box. Annually
Drain hydraulic reservoir and clean. Annually
Check hoist rollers for wear X No more than1/4” wear
OIL OPERATING TEMPERATURE RANGE
RECOMMENDEDGRADE OF
HYDRAULIC FLUIDCLIMATE AMBIENT
TEMPERATURE
MAXIMUM BULK OIL(RESERVOIR
TEMP.)
ISO 32 Hot Above 60° F (15° C) 180° F (82° C)
ISO 15 Moderate 20° F (-7° C) -100° F (38° C) 165° F (74° C)
ISO 5 Cold Below 32° F (0° C) 150° F (60° C)
PERIODIC MAINTENANCE CHART
PROCEDUREPERIOD (HOURS)
8 250 OTHER
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SERVICING 2-1Page 3
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
4. FILLING HYDRAULIC OIL RESERVOIR
1. Check hydraulic oil level as described above.
2. Determine the amount of oil to be added: 2.5 gallons of oil will raise the level in the reservoir about 1 inch.
3. Raise the work platform if necessary to access the reservoir filler cap. Support platform with the maintenance stand.
4. Clean the area around the filler/breather cap.
5. Remove cap and check strainer screen for any foreign material.
6. Clean thoroughly before putting hydraulic oil into the reservoir.
7. Use only clean, uncontaminated oil, filtered to 10M. Add the quantity of oil determined in step 2.
8. Secure cap when finished.
9. Recheck hydraulic oil level.
Figure 1HYDRAULIC OIL FILL POINT
5. LUBRICATION
A. Grease Points
NOTE: Use any commercially available “MP” multipurpose grease which meets NLGI Grade 1 or 2 standards.
Wipe grease fittings clean and apply grease. Before coating tracks with grease, clean surfaces toremove dirt and foreign material (ref. Figure 2 thru Figure 8).
B. Oil Points
NOTE: Use SAE 5W-30W oil or other adequate Lubricants with brush or oil can as appropriate (ref. Figure 9).
Lift Cylinder Rods - Apply oil to reduce cylinder noise as needed which may be caused by dryseals.
HYDRAULIC FILL POINT(HYDRAULIC OIL ONLY)
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MAINTENANCE2-1Page 4
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
NOTE: The scissors lift must be raised to access the grease points. Make sure to put maintenance prop up.
NOTE: Check at intervals listed and lubricate as required. In unusual weather conditions, check at more frequent intervals.
GREASE POINTS
ITEM COMPONENT TOTALFITTINGS INTERVAL
1 Scissor pivot pins (Upper/Middle/Lower) 12 6 mos.
2 Scissor Arm End Pins 4 6 mos.
3 Scissor roller (Upper/Lower) 8 6 mos.
4 Traversing roller pins 4 6 mos.
5 Lift cylinder (Upper/Lower) 8 6 mos.
6 Traversing cylinder rod ends 2 6 mos.
7 Booster arm pivot 1 6 mos.
8 Stabilizers 16 6 mos.
9 Roller Tracks 3 mos.
GREASE
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SERVICING 2-1Page 5
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
WARNING
THE SCISSOR LIFT MUST BE SECURED WITH THE MAINTENANCE PROP BEFORE ACCESSING THE GREASE POINTS.
Figure 2GREASE POINTS DIAGRAM
Ref. Figure 7
Ref. Figure 8
Ref. Figure 7
Ref. Figure 6
Ref. Figure 3
1
3 6
7
15
1
3
2
4
5Ref. Figure 3& Figure 4
Ref. Figure 6
Ref. Figure 7
Ref. Figure 7
Ref. Figure 7
Ref. Figure 7
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MAINTENANCE2-1Page 6
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 3GREASE POINTS - LIFT CYLINDERS UPPER
TOP LIFT CYLINDER
BOTTOM LIFT CYLINDER
1. Set the maintenance prop. Refer to Chapter 1-2.
2. Raise or lower the lift to access all grease points of upper lift cylinder rollers (4).
GREASE POINT
GREASE POINT
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SERVICING 2-1Page 7
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 4GREASE POINTS - LIFT CYLINDERS BOTTOM
Figure 5GREASE POINTS - STABILIZERS
TOP LIFT CYLINDER
BOTTOM LIFT CYLINDER
GREASE POINTGREASE POINT
GREASE POINT - 4 PER LEG
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MAINTENANCE2-1Page 8
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 6GREASE POINTS - TRAVERSING CYLINDER AND ROLLERS
GREASE POINT
TRAVERSING CYLINDER ROD ENDS - BOTH ENDS
GREASE POINT - BOTH ENDS
TRAVERSING ROLLER PINS - 8 PLCS
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ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 7GREASE POINTS - SCISSOR ROLLERS AND PINS
SCISSOR PIVOT PINS - BOTH SIDES& UPPER AND LOWER
SCISSOR ARM END PINS - 4 PLCS
SCISSOR CENTER PINS - BOTH SIDES
UPPER AND LOWER
UPPER SCISSOR ROLLERS - BOTH SIDES
SCISSOR LOWER ROLLER PINS - BOTH SIDES
NOTE: To grease lower scissor rollers, lift must be down.
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MAINTENANCE2-1Page 10
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 8GREASE POINT - LOWER BOOSTER ARM
Figure 9GREASE POINTS - TRACKS AND BOOSTER ARM UPPER LIP
GREASE POINT
GREASE W/BRUSH
SCISSOR ROLLER TRACKS - BOTH SIDES& UPPER AND LOWER
BOOSTER ARM LIP
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SERVICING 2-1Page 11
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 10OIL POINTS
OIL POINTS
ITEM COMPONENT TOTALPLCS INTERVAL
1 Lift Cylinder Rods 4 6 mos.
2 Platform entry swing gate hinge points & Lock 3 1 mos.
3 Platform Ext. Segments Pocket & Locking Bar 1 mos.
OIL
NOTE: Use SAE 5W-30W oil or other adequateLubricants with brush or oil can as appropriate.
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HYDRAULIC SYSTEM ADJUSTMENTS 2-2Page 1
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Section 2: Hydraulic System Adjustments
WARNING
BEFORE STARTING ANY ADJUSTMENT PROCEDURE THAT REQUIRES THE PLATFORM TO BE IN AN ELEVATED POSITION, MOVE THE MAINTENANCE STAND INTO POSITION AND LOWER THE PLATFORM FULLY AGAINST THE MAINTENANCE PROP.
WARNING
IT IS MANDATORY THAT EYE PROTECTION (SAFETY GOGGLES OR FACE SHIELD) BE WORN WHEN MAKING PRESSURE CHECKS AND/OR ADJUSTMENTS ON THE HYDRAULIC SYSTEM. HYDRAULIC OIL WILL CAUSE EYE INJURIES. IF HYDRAULIC OIL GETS ON THE SKIN, WASH AFFECTED AREA IMMEDIATELY TO AVOID IRRITATION.
WARNING
DRIVE WHEELS MUST BE CHOCKED TO PREVENT MOVEMENT OF THE UNIT IN EITHER DIRECTION.
WARNING
WHEN MAKING PRESSURE CHECKS OR ADJUSTMENTS, USE GAUGES WITH KNOWN ACCURACY. IMPROPER HYDRAULIC ADJUSTMENTS CAN CAUSE INJURY TO PERSONNEL OR DAMAGE TO EQUIPMENT.
WARNING
DO NOT REMOVE GAUGE PORT PLUGS OR GAUGES, OR LOOSEN HYDRAULIC CONNECTIONS WITH THE UNIT RUNNING. HYDRAULIC PRESSURE IN THE SYSTEMS COULD CAUSE HYDRAULIC OIL TO SPRAY ON PERSONNEL.
CAUTION
USE EXTREME CARE TO PREVENT CONTAMINATION OF HYDRAULIC SYSTEM WHEN INSTALLING GAUGES, FITTINGS, OR REPLACING A COMPONENT. CONTAMINATION CAN RESULT IN EQUIPMENT DAMAGE.
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MAINTENANCE2-2Page 2
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
CAUTION
WHENEVER AN ADJUSTABLE HYDRAULIC RELIEF VALVE OR PRESSURE REDUCING VALVE IS REPLACED, REDUCE THE PRESSURE SETTING PRIOR TO STARTING THE UNIT. ADJUST THE REPLACED COMPONENT TO SPECIFICATION AS OUTLINED IN THE ADJUSTMENT PROCEDURES.
CAUTION
WHEN MAKING HYDRAULIC SYSTEM ADJUSTMENTS, THE HYDRAULIC OIL MUST BE AT NORMAL OPERATING TEMPERATURE.
1. HYDRAULIC ADJUSTMENTS - HYDRAULIC POWER MODULE
ITEM FUNCTION SETTING PROCEDURE
A Pressure Gauge N/A Used for reading system pressures.
B Lift Down Speed Control
90 sec+/- 10
Raise lift fully. Activate lift down function and record the time it takes the lift to lower fully (not including stabilizer retract). Adjust valve to increase/decrease lift lower speed. Loosen locknut and turn valve clockwise to slow lift speed, counter-clockwise to increase lift speed. Tighten locknut when adjustment is complete.
C Main Relief 1800 psi+/- 25
With the engine running, extend the stabilizers to the maximum and hold control in “Extend”. Read the pressure at the gauge. To adjust the pressure, loosen the locknut on valve. Turn valve clockwise to increase pressure, counter-clockwise to lower pressure. Tighten locknut when pressure is set.
D Stabilizer SpeedControl(Left Rear Stab.)
N/A Make certain that left rear stabilizer is last to fully extend and last to fully retract. Loosen locknut and turn valve clockwise to slow stabilizer speed, counter-clockwise to increase stabilizer speed. Tighten locknut when adjustment is complete.
E Port Relief 1,200 psi+/- 25
Energize lift down function, read pressure at gauge. Turn valve clockwise to increase pressure, counter-clockwise to lower pressure.
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HYDRAULIC SYSTEM ADJUSTMENTS 2-2Page 3
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 1HYDRAULIC SYSTEM
F
G
StabilizerPressure Reducing Valve
Stabilizer Pressure Switch(Left Rear)
N/A Fully retract lift and stabilizers. Turn valve fully clockwise and extend/retract stabilizers till all stabilizers operate smoothly and consistently with the left rear stabilizer last to extend and last to retract (See Adjustment D). Then turn valve counter-clockwise till chassis is lifted between 1 & 2 in. (2.54 am & 5.08 am). Fully retract stabilizers between adjustments. Chassis must be level +/- 1 in. (2.54 am) side to side.
Ensure Stabilizer Pressure Switch still just activates when stabilizers are extended. Screw in adjustment to increase the pressure needed to activate the switch. Screw out to decrease. Retract stabilizers and verify pressure switch deactivates.
H Compressor Pressure Relief
N/A Open the valve all the way counter clockwise. While the compressor is running continue to raise the lift. Adust valve (clockwise) until the lift operates smoothly. Turn valve clockwise to increase pressure, counter-clockwise to lower pressure.
ITEM FUNCTION SETTING PROCEDURE
A
C
B
DE
F
STABILIZER
G
H
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MAINTENANCE2-2Page 4
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
2. HYDRAULIC ADJUSTMENTS - TRAVERSING PLATFORM VALVE
A. Flow Control Valve
1. Loosen locknut (A).
2. Turn clockwise to to slow down and counter-clockwise to speed up.
3. Tigntened locknut.
Figure 2TRAVERSING PLATFORM VALVE
A
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HYDRAULIC SYSTEM ADJUSTMENTS 2-2Page 5
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
3. COUNTER BALANCE/HOLDING VALVE-HOLD PRESSURE ADJUSTMENT
NOTE: The pressure on the counter balance holding valves is preset by TESCO at 1400 PSI. Adjustments are accomplished using an Allen wrench on the pressure adjuster and a standard open end wrench on the locknut.
NOTE: Counter Balance/Holding Valves should be pre-adjusted before installation by turning adjustment screw clockwise all the way and backing out one and three quarter (1 3/4) turns for 1400 PSI setting.
1. Extend stabilizer cylinders and partially raise lift. Install maintenance prop.
NOTE: Adjust one counterbalance valve at a time.
2. Loosen locknut.
3. Increase holding pressure by turning adjusting screw counter-clockwise direction. Each one eight (1/8) turn is equal to 100 PSI increase in holding pressure (ref. Figure 3).
4. Decrease holding pressure by turning adjusting screw clockwise direction. Each one eight (1/8) turn is equal to 100 PSI decrease in holding pressure.
5. Tighten locknut when adjustment is complete.
Figure 3COUNTER BALANCE/HOLDING VALVE
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MAINTENANCE2-2Page 6
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
4. LIFT DOWN FLOW CONTROL VALVE ADJUSTMENT
(Ref. Figure 4)
The flow control valve is used to restrict the amount of hydraulic oil being used to open the uppercounter balance valves. To have the upper cylinders work with the lower cylinders so that they can comedown together. The lowering speed may be adjusted to increase or decrease the hi-lift’s lowering speed.
1. Raise the scissor to the maximum height.
2. Activate lift down function and record the time it takes the lift to lower fully.
Lift Lower 90 sec +/-10
3. Loosen locknut and turn adjusting screw clockwise to slow lift speed, counter-clockwise to increase lift speed.
4. Tighten locknut when adjustment is complete.
Figure 4LIFT DOWN FLOW CONTROL VALVE ADJUSTMENT
LOCKNUT
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TROUBLESHOOTING 2-3Page 1
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Section 3: Troubleshooting
1. GENERAL INFORMATION
WARNING
ONLY QUALIFIED TECHNICIANS, WHO HAVE BEEN TRAINED IN THE USE AND OPERATION OF THIS EQUIPMENT, SHOULD ATTEMPT ANY TROUBLESHOOTING. THE CHASSIS WHEELS MUST BE CHOCKED TO PREVENT THE HI-LIFT UNIT FROM MOVING IN EITHER DIRECTION. THE MAINTENANCE PROP MUST BE INSTALLED FOR SUPPORT WHENEVER THE PLATFORM IS RAISED FOR MAINTENANCE OR ADJUSTMENTS. FAILURE TO FOLLOW GOOD SAFETY PRACTICES DURING MAINTENANCE OR TROUBLESHOOTING COULD RESULT IN DEATH OR SERIOUS INJURY TO PERSONNEL AND/OR DAMAGE TO EQUIPMENT.
The information contained in this section is provided as a guide to assist technical service personnel introubleshooting operational malfunctions in the ML5-30 Lift Unit hydraulic and electrical systems.
1. Before starting troubleshooting procedures, verify that the correct operating procedures were used. An incorrect operating procedure can cause apparent malfunctions.
2. The most important practice to observe when working on the hydraulic system is cleanliness. Serious damage can result quickly from foreign material in the hydraulic system. When a hydraulic system is opened, cap or plug all ports and openings to keep foreign material and moisture-laden air from entering the system. DO NOT use Teflon tape or pipe compound on straight threads.
NOTE: Refer to the troubleshooting chapter in the chassis manufacturer’s manual for chassis troubleshooting instructions.
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MAINTENANCE2-3Page 2
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
1. INTRODUCTION
The Tesco ML50-30 Lift is a hydraulically operated, electrically controlled maintenance lift. Thehydraulic and electrical systems require a thorough understanding to determine the cause of amalfunction or failure of a component. System diagnosis is mandatory to locate a component that is outof adjustment or has failed.
2. HYDRAULIC SYSTEM
1. The hydraulic system is an open-center system.
2. The hydraulic system diagnosis is accomplished by observing the readings on the pressure gauge or timing a function when a particular hydraulic circuit is actuated. The hydraulic schematics and adjustment procedures indicate the correct setting for each pressure and flow adjustment.
3. The first step in diagnosing a malfunction is to isolate the malfunction to the hydraulic system or to the electrical control system.
NOTE: All solenoid actuated control valves in the hydraulic system are equipped with a manual override that can be used to actuate the valve should there be a loss of electrical current. The manual override shifts the valve spool and permits oil flow for the Hi-Lift function to operate. The pressure gauge can be observed for the correct pressure reading for the system in use.
NOTE: To obtain oil flow the PTO must be activated with the ENABLE switch. Alternatively, for test or emergency operation, the hand pump or optional electric auxiliary hydraulic pump may be used to provide hydraulic flow.
Press both UP switches simultaneously if not equipped with an ENABLE switch. In thiscase one of the UP switches function as the ENABLE switch.
3. ELECTRICAL SYSTEM
The Model ML50-30 has a 12-volt DC electrical system that controls all functions of the Hi-lift. Thecomponents of the electrical system are located in the lower control station, the upper control station,and the main electrical box. Limit switches in various locations sense a specific position of a mechanicalcomponent for the actuation and interlocking of electrical circuits. The electrical box is located below thevan body usally on the passenger’s side mounted on the hydraulic module. It consists of relays, diodes,circuit breakers, and terminal blocks. See Chapter 1, Section 2 for the location and function of each ofthe separate control stations.
4. TROUBLESHOOTING GUIDE
The following guide lists Hi-Lift malfunctions and some possible causes for those malfunctions. Whenthere is a problem or malfunction of the Hi-Lift, read through the list on the left side of the chart. Possiblecauses are listed to the right.
Hydraulic component problems are usually caused by oil contamination, and many components can bemade serviceable by a thorough cleaning. Hydraulic filter elements must be replaced when a systemhas been cleaned of contamination.
Hydraulic troubleshooting can be done using a pressure gauge and the hydraulic schematics.
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TROUBLESHOOTING 2-3Page 3
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
When a component is repaired or replaced, always check the hydraulic circuit for the correct indicatedpressure, correct actuator speeds, and correct hydraulic fluid level.
A. Troubleshooting Chart - General
TROUBLESHOOTING
TROUBLE PROBABLE CAUSE
Ground level controls will not operate with the vehicle’s engine running.
Vehicle not in lift mode (Parking brake off)
Emergency stop activated
Circuit breaker tripped or blown fuse
Defective solenoid coil or relay
Damaged or defective control switch
Damaged wiring or bad ground
Damaged Power Take Off (P.T.O.) or pump drive components
Stabilizers will not hold retracted or extended position.
Faulty check valve
Faulty cylinder
Stabilizers will not retract Vehicle not in lift mode (Parking brake off)
Hi-Lift not fully lowered or stowed
Circuit breaker tripped or blown fuse
Defective relay
Defective Hi-Lift or stabilizer interlock switch
Damaged or defective control switch
Defective valve cartridge
Damaged wiring or bad ground
Damaged Power Take Off (P.T.O.) or pump drive components
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MAINTENANCE2-3Page 4
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Stabilizers will not extend. Vehicle not in lift mode (Parking brake off)
Emergency stop activated
Circuit breaker tripped or blown fuse
Defective solenoid coil or relay
Damaged wiring or bad ground
Damaged or defective control switch
Defective valve cartridge
Damaged Power Take Off (P.T.O.) or pump drive components
Emergency lowering handpump is not operating. Manual overrides not open
Upper controls will not operate with the vehicle's engine running.
Vehicle not in lift mode (Parking brake off)
Enable switch not depressed
Stabilizers not fully deployed
Emergency stop activated
Circuit breaker tripped or blown fuse
Damaged or defective control switch
Defective enable relay
Defective solenoid coil or relay
Damaged wiring or bad ground
Damaged Power Take Off (P.T.O.) or pump drive components
Vehicle’s engine will not turn off when the EMERGENCY STOP SWITCH on either control station is actuated.
Damaged or defective control switch
TROUBLESHOOTING
TROUBLE PROBABLE CAUSE
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TROUBLESHOOTING 2-3Page 5
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Platform mounted spotlight not operating. Burned fuse
Dead or low battery
Defective light bulb in spotlight
Corrosion build up on light bulb terminals
Faulty toggle switch on light assembly
Faulty ground at spotlight caused by corrosion
Faulty wiring harness
Hi-lift settles or does not hold position when control is released.
Air trapped in a lift cylinder
Misadjusted, faulty or sluggish counter balance hold valve on the lift cylinder
Defective lift cartridge valve
Hi-lift unit racked or twisted in one direction during raising or after reaching required height.
Exceeding maximum load capacity
Off center load on work platform
Air trapped in lift cylinder
Misadjusted, faulty or sluggish counter balance hold valve on the lift cylinder
Leak in one of the lift cylinder
Low hydraulic fluid level in reservoir
Faulty hi-lift scissors center pivot pin, attach pin, or roller axle
Hi-lift unit racks or twists during lowering. Off center load on work platform
Air trapped in lift cylinder
Misadjusted, faulty or sluggish counter balance hold valve on the lift cylinder
Uneven holding valve release pressure
TROUBLESHOOTING
TROUBLE PROBABLE CAUSE
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MAINTENANCE2-3Page 6
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
There is no hydraulic fluid flow or pressure from hydraulic oil pump when the engine is running.
Shut off valve closed
Clogged filter
Blockage on pump's suction port or collapsed suction hose
Damage to pump gears or wear plates
Pump does not respond to load immediately or fails to respond totally.
Low hydraulic oil level in reservoir
System relief valve pressure set too low
Pump worn or damaged
Overheated hydraulic oil. Hydraulic oil level too low
Hydraulic oil dirty and deteriorated
Hydraulic oil viscosity too light for climate
Hydraulic oil continuously flowing over relief valve
Relief valve pressure is set too low or too high
Worn pump or internal damage to pump
Hydraulic oil pump is noisy. Low hydraulic oil level
Hydraulic oil viscosity too heavy
Restricted hose or collapsed suction hose
Air leak in suction hose between suction outlet and pump’s inlet port
Hydraulic oil temperature too high
Pump pulling air through the input shaft’s seal when no load condition exists on pump
Hyd. oil foaming excessively Hydraulic oil level too low
Air leak on section hose between suction outlet and pump’s inlet port
Incorrect type or grade of hydraulic oil
TROUBLESHOOTING
TROUBLE PROBABLE CAUSE
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REPAIRS 2-4Page 1
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Section 4: Repairs
WARNING
DO NOT ALLOW PERSONNEL UNDER THE HI-LIFT UNLESS THE MAINTENANCE PROPS ARE IN PLACE. FAILURE TO SUPPORT THE PLATFORM MAY ALLOW PLATFORM TO FALL, RESULTING IN DEATH OR INJURY TO PERSONNEL OR DAMAGE TO EQUIPMENT.
WARNING
USE EYE PROTECTION AND PROTECTIVE CLOTHING RECOMMENDED BY THE MANUFACTURER OF THE WELDING EQUIPMENT THAT IS USED.
1. INTRODUCTION
All welded repairs must conform to the American Welding Society (AWS) Codes D1.1 2004, AWSD14.1-97 and to the Society of Automotive Engineers (SAE) ARP 1330A standards. Welders performingrepairs must be qualified to MIL.STD.-1595. Welded joint configuration and preparations must be inaccordance with existing AWS DD1.1 welding code for structural welding.
2. STRUCTURAL REPAIRS
A. Scissor arms
Welded repairs on scissor arm’s structural tubing are not permitted. Consult with Tesco forapproved methods or guidelines for conducting repairs.
B. Scissor frame or van body
Repair cracks or damage by welding or splicing as required except where the structural integrityof the unit is affected. Consult with Tesco for approved methods or guidelines for conductingrepairs on damaged area.
C. Handrails
Replace sections of damaged handrail with a new piece of metal. Weld into place.
D. Surface rust or scratches
Repair by sanding or cleaning rust with a wire brush. Prepare metal with metal etching chemicalbefore priming and painting.
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SYSTEM SCHEMATICS 2-5Page 1
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Section 5: System Schematics
1. HYDRAULIC SCHEMATIC
A. 4 Stabilizers & 12VDC Pump with Return Filter Figure 1
2. ELECTRICAL SCHEMATIC
A. How to Read This Schematic Figure 2
B. Electrical Schematic, Engine & Chassis - Sheet 1 of 9 Figure 3
C. Electrical Schematic, Lighting - Sheet 2 of 9 Figure 4
D. Electrical Schematic, Lift & Stab. Control - Sheet 3 of 9 Figure 5
E. Electrical Schematic, Lift & Stab. Control - Sheet 4 of 9 Figure 6
F. Electrical Schematic, Options - Sheet 5 of 9 Figure 7
G. Electrical Schematic, Options - Sheet 6 of 9 Figure 8
H. Electrical Schematic, Options - Sheet 7 of 9 Figure 9
I. Electrical Schematic, Tables of Veh. Connections - Sheet 8 of 9 Figure 10
J. Electrical Schematic, Tables of Veh. ConnectionsDPDT & SPDT Relay Wiring - Sheet 9 of 9 Figure 11
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MAINTENANCE2-5Page 2
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 1HYDRAULIC SCHEMATIC - 4 STABILIZERS & 12V PUMP WITH RETURN FILTER
18 G
PM
@ L
O T
HR
OT
TLE
23 G
PM
@ H
I T
HR
OT
TLE
WIT
H O
N-D
EM
AN
D
EN
GA
GE
ME
NT
F
LO
WS
AV
AIL
AB
LE
: Z
ER
O (
DIS
EN
GA
GE
D)
DLD
A-D
HN
VA
LV
E
OR
XG
CA
-XX
N P
LU
G
T-1
3A
CA
VIT
Y
T-2
2A
CA
VIT
Y
T-5
A C
AV
ITY
T-1
6A
CA
VIT
Y
NF
DD
-LG
N
FD
EA
-LA
N
RV
ED
LA
N
CO
DE
61
-16
CO
DE
61
W/O
-RIN
G
W/O
-RIN
G
-32
(OP
TIO
NA
L)
RE
AR
LE
FT
SID
E
STA
BIL
IZE
R
FR
ON
T
RIG
HT
SID
E
STA
BIL
IZE
R
FR
ON
T
LE
FT
SID
E
STA
BIL
IZE
R
V1
V2
C2
C1
RE
AR
RIG
HT
SID
E
STA
BIL
IZE
R
V1
V2
C2
C1
V1
V2
C2
C1
V1
V2
C2
C1
A
FR
OM
MA
IN
MA
NIF
OLD
AU
X P
PO
RT
AIR
CO
MP
RE
SS
OR
- O
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ION
AL
HY
DR
AU
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DR
IVE
N/C
OO
LE
D
TR
AV
ER
SE
C
YLIN
DE
R
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WC
ON
TR
OL
PLA
TF
OR
M T
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VE
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E
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3 T
YP
E
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LV
E
N.C
. C
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CK
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AN
IFO
LD
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INE
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-6-1
6-6
-81/8
NP
T
DO
5 T
YP
E
STA
BIL
IZE
R
VA
LV
E
SO
L3
750/3
000
T
P
SO
L4
PR
ES
SU
RE
RE
DU
CE
RP
RS
BLA
N
EN
GIN
E D
RIV
EN
PU
MP
M
CH
EC
KV
ALV
E
SO
L2
TA
NK
VA
LV
E
ISO
LA
TIO
N
RE
SE
RV
OIR
50 G
AL
-16
ALR
B2
AU
X P
-6A
1-1
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-10
SY
ST
EM
RE
LIE
F
1800 P
SI N
OM
.
T
P
FLO
W C
ON
TR
OL
(NE
ED
LE
VA
LV
E)
LO
WE
RIN
GF
LO
W C
ON
TR
OL
AU
X P
G
1P
1
13
42
SO
L1
OP
TIO
NA
L
PB
U V
ALV
E
SA
ND
WIC
H
RE
LIE
F
-12
AU
X T
HA
ND
P2
PU
MP
SS
UC
TIO
N
D
G2
-04
(ALT
ER
NA
TIV
E T
O
RE
TU
RN
UP
TO
50 G
PM
RE
TU
RN
FIL
TE
R
PR
ES
S. F
ILT
ER
S)
BR
EA
TH
ER
T
LIF
T V
ALV
E
D05 T
YP
E
VA
LV
ES
LIF
T C
YLIN
DE
RS
SO
L5
CO
MP
RE
SS
OR
SO
LE
NO
ID
SO
L9
SO
L1
0
& R
ES
ER
VO
IR
PU
MP
12V
DC M
12 V
DC
EM
ER
GE
NC
Y P
UM
P
B1
-12
SO
L6
LO
WE
RIN
G
ML2 5
030 H
ydra
ulic
Syste
m w
ith F
PP
Retu
rn F
ilter
Manifold
s
1
2
511
5
12
9 9
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SYSTEM SCHEMATICS 2-5Page 3
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
ITEM QTY TESCO NO PART NUMBER/DESCRIPTION NOTE
1 1 326-9110-490 • PUMP, 19 GPM
2 1 TR5012112NFHXNFXB • HYDRAULIC POWER MODULE
1 HYMS20046 •• CARTRIDGE, Systm Relief Valve
1 HYMS20047 •• CARTRIDGE, Stabilizer Flow Control Valve
1 HYMS20049 •• CARTRIDGE, Handpump Valve
1 HYMA10008 •• MANIFOLD, W/Return Filter Provision
1 HYVA10245 •• CARTRIDGE, Pressure Reducing500-3000 psi
4 HYMS20042 •• COIL, D05 12VDC Lift & Stabilizer
2 HYMS20041 •• VALVE, D05 3 Pos./4 Way Lift & Stabilizer
1 HYMS20055 •• MANIFOLD, Sandwitch, Port Relief
1 HYVA10247 •• CARTRIDGE, Port Relief
1 HYMS20048 •• CARTRIDGE, Lift Flow Control Valve
1 HYMS20045 •• GAUGE, 0-3000 PSI
1 HYMS20052 •• VALVE, Check, Inlet
1 HYFI10017 •• FILTER ELEMENT, Return
1 HYMS20051 •• PUMP, AUXILIARY 12VDC
1 HYVA10273 •• SANDWICH VALVE, Relief Lift
1 HYVA10149 •• CARTRIDGE, PBU Valve
5 4 HYVA10120 • CARTRIDGE, Counter Balance Valve
4 HYVA10121 • BODY, Counter Balance Valve
9 4 HYCY10027 • CYLINDER, Double Acting Stabilizer
11 2 HYCY10005 • CYLINDER, Single Acting Lift
12 2 HYCY10006 • CYLINDER, Single Acting Lift
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TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
MAINTENANCE2-5Page 4Dec. 06
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SYSTEM SCHEMATICS 2-5Page 5
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 2HOW TO READ THIS SCHEMATIC
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MAINTENANCE2-5Page 6
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 3ELECTRICAL SCHEMATIC, ENGINE & CHASSIS - SHEET 1 OF 9
6
BATTERY
BACKUPALARM
HOURMETER
+ -
112
LS3
102
104
203
CC1-A
IP
CC1-B
CC2 CC
EN
110
ENGINE STOP
ENGINERUNNING
IGN ON
CC
CC1-C
NEUTRAL200
203
IGNITION
12VDC
IGNITION SW.
100 -
101 -
102 -
103 -
104 -
105 -
106 -
107 -
108 -
109 -
112 -
110 -
111 -
ENGINECONTROLMODULE
HI THROTTLE
STARTER
BACKUP ALARMSTARTERREVERSE SWITCH
(CLOSED IN REVERSE)
HOUR METER STOP
113 -
114 -
115 -
116 -
117 -
TRANSMISSIONOIL PRESS.
(ENGINE RUNNING)
PS1
118 -
119 -
120 -
121 -
PARK BRAKE
122 -
PARKING BRAKE(CLOSED WHEN SET)
309
152
123 -
124 -
125 -
126 -
127 -
IGN+12V
- 12V
NOTE: WHEN CIRCUIT IS OPEN TRANSMISSION IS LOCKED IN NEUTRAL
ENGINE & CHASSIS
221
125
2 2
4
6
10
EN
MAIN
CC
CB060A
ENGINE STOP
8
ENGINE STOP
START
STOP
SW2-AUC-1
ON
SW2-B5
UCS10
7
UC
7
7
41SW2-C
SW2
UCS9 41 CC3ENGINE RESTART J10UC9
J11UC10
J1
UCS-1
J2UCS-2 UC2
12 VOLT ENABLE
2
3
3
200
RESTART
200ENGINE STOP
[OPT.]
B
AREVERSE FLOOD[OPT.] 153
CC1-D
E
[OPT.]
224
IGNITION
101CR2
MB
MBMB
R12MB
MB
MB
CR10
(HIGH THROTTLE)
CR1
CB110A CR1
(IGNITION ON)
CR3
CR4MB
R13
25430 87
7 2
86 85
7 2
4
+12V
8
IGN
IGN
IGN
CB1
11
MAIN BOX MAIN BOX
(ENGINE STOPPED)
110
68
R11
D1MB
7
R11
2
MB
CR2112
87a30
(ENGINE STOPPED)
110
41
R11
CR14MB
OFF
STARTIGN
LS1
IP
EN
CC
ECM
SW1
CHASSIS CHASSIS
Red/Blk
Orange
Red
Brown
Red Blue
11
Brown/Black
WhiteBlack
Brown/Red
Red/Blk
Red
Orange
PTO HARNESS
+ -
NOTE: REMOVE STANDARD JUMPER
FROM IGN TO TERM 5
FORD: USE GROUND [STD]ISUZU: MOVE TO +12V FROMLIFT CIRCUIT - SEE LINE 224
IGN; park switch is groundInternational/Ford Hyd Brakes: move R13 toFORD Air Brakes/GMC as shown
0.2A
NEGLIGIBLE A
0.2A ADDED BY TESCO
0.2A
0.4A
0.2A
0.2A
0.4A
6.8A
47.6A 0.2A
REV. C
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SYSTEM SCHEMATICS 2-5Page 7
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 4ELECTRICAL SCHEMATIC, LIGHTING - SHEET 2 OF 9
IP CC7
GC
IGN+12V
150 -
151 -
152 -
153 -
154 -
155 -
156 -
157 -
158 -
159 -
162 -
160 -
161 -
163 -
164 -
165 -
166 -
167 -
168 -
169 -
170 -
171 -
172 -
173 -
174 -
175 -
176 -
IGN+12V
- 12V
- 12V
HEADLIGHT SWITCH
SW3
FLASHER
BEACON
SW7
LIGHTING
13 14
15 16
15A
GC7
15
35 40
15A
LX
P
MB
J13 J7
PLATFORM WORK LIGHTS
SW6
LIGHTS (2)PLATFORM WORK
BP
WORKLIGHTS
LT3
(2)
CB240A
211
MB
8730
(IGN. ON)
CR3
R15
(BODY DOWN)
(BODY DOWN)LIGHTS
116R15
211
8 6
1 4
MAIN BOX
MAIN BOX
CHASSIS
CHASSIS
35 40
LT-5A
LT-5
UCS12 UCS13
UCS11 UCS6
Orange
27.6A
= 2 X 35W6.0A
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TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 5ELECTRICAL SCHEMATIC, LIFT & STAB. CONTROL - SHEET 3 OF 9
LIFT & STABILIZERS CONTROL
BODY DOWN
STABILIZEREXTENDED
LOWER E-STOP PENDANT E-STOP
(CLOSED WHEN EXT'D)
STABL. EXT'D
BODY UP
ENGINE STOP
R
BODY DOWN
LIFT MODE
LT6
STAB EXT'D
A
261
150
217
152
259
LIFT MODE
G
IP
IP
IPLIFT POWER
[OPT.]
BODY UP
STABSNOT STOWED
200 -
201 -
202 -
203 -
204 -
205 -
206 -
207 -
208 -
209 -
212 -
210 -
211 -
213 -
214 -
215 -
216 -
217 -
218 -
219 -
220 -
221 -
222 -
223 -
224 -
225 -
226 -
227 -
IGN+12V
+12V
UCGC
SW9 SW10-B
221
- 12V
- 12V
GC5 GC6 PC7 PC8
LT7
LT8
SW10-AUC
UPPER E-STOP
UC7 UCS8UCS7 PC8 UC8
219125
STABILIZERSTOWED
STABL. STOWED
PS5ST1 3
2
(CLOSED WHEN STOWED)
SCPS7
(BODY DOWN)
1 3
2
STPS2 STPS2
200
ST
STABILIZERSTOWED
PS2
B ENGINE STOP[OPT.]
OVERRIDE [OPT]
STABL. EXT'D STABL. EXT'D STABL. EXT'D
[OPT. MULTIPLE STABILIZER SWITCHES]
STABL. STOWED
LS6-A LS6-B LS6-C
113
IP
STSTST
SW11
E
CC1-D[OPT.]
105
OPT. +12V LIFT SIGNALFOR HIGH THROTTLEFOR CHASSIS OTHERTHAN FORD
STABL. STOWED
PS5-AST1 3
2
PS5-B PS5-CST ST1 3
2
1 3
2
PS5-B PS5-CST ST1 3
2
1 3
2
30
CR4
87A
30
R13
87 8 6
CR4 CR6
(BRAKE SET)
8586
CR7
R15
R16
R16
41
(NEUTRAL)
(NEUTRAL)
STABL. EXT'D
(BODY DOWN)
CB320A
LIFT CONTROL
LIFT MODE
86 85
R14
(STABS STOWED)
118
120118
213
207
MB
MB
MB
MB
(LIFT MODE)
30 87
CR6203MB
MB
MB
MB
D2
D3
D4R12 114
(ENGINE RUNNING)
IGN LIFTMODE
7 2
7 2
1 4
8 6
IGN
IGN
IGN
IGN
17
18 J161817A17
37
21
37
2222
23
24
LIFT
25
26
27
27
27
BODY DOWN
BODY DOWN
IGN
IGN
+12V
MAIN BOX
LIFT
21
23
24
25
26
27
19 J8J15 J9
R14
STABL. STOWED
MB
7 220
20IGN
86
STABL. STOWED
85
CR13
[ENG. STOP OPT.]
MB
30
CR13
87A
(STAB STOWED)
205 3617B17B 17C
30
CR14
87A
(STAB STOWED)
109 7
CHASSIS
Black Red
Orange/Blk Orange/Red
Blue/Blk Blue/Red
Black Black/Red
Brown (4)
Blue (4)
Brown
Rh/Wht Gr/Ylw
Rd/Blk
BlackBlack
0.2A
0.2A
0.4A
0.4A
1.5A
1.5A
1.5A13.2A 13.2A4.5A
1.5A
1.5A
0.4A
0.2A
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SYSTEM SCHEMATICS 2-5Page 9
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 6ELECTRICAL SCHEMATIC, LIFT & STAB. CONTROL - SHEET 4 OF 9
LIFT UP [LOWER]
LIFT UP LIFT UP
SOL5
[UPPER]
[LOWER]
MAX HEIGHT(OPEN @ HEIGHT)
LOWERING ALARM
LIFT UP
LOWER ALARM
MOTION ALARM
STABILIZERS
STABILIZERS
ENABLE
STABL. RETRACT
STABL. EXTEND
SOL4
SOL3
PTO
SOL2
STABILIZERS
PTO
STABILIZERS
EXTEND
RETRACT
[UPPER]
[LOWER]ENABLE
EXTEND
RETRACT
LIFT DOWN
LIFT DOWN
[UPPER]
UC
GCEN
AG
MVAG
MV
MV
CC
ALL
[OPT.]
250 -
251 -
252 -
253 -
254 -
255 -
256 -
257 -
258 -
259 -
262 -
260 -
261 -
263 -
264 -
265 -
266 -
267 -
268 -
269 -
270 -
271 -
272 -
273 -
274 -
275 -
276 -
+12V
IGN+12V
SW12
SW13
SW14
SW15
SW14-B
SW14-A
SW15-A
SW15-B
SW15-C
SW16
SW17
SW18
SW19
-12V
PC-3 PC-4
GC-1 GC-2
AG-1
AG-2
AG-4
AG-3
HIGH THROTTLE
105
PC-3
GC-1
PC-3
GC-1
PC-6
GC-4
GC-3
PC-5UC
GC
UC
GC
UP INHIBIT261
LIFT DOWN
SOL6
LIFT DOWN
SC
-12V
(PLAT. RETRACTED)
LT-3BP
UC-6
UCS3
UC4
UC5
THROTTLE INHIBIT254
MODELIFT
UC3
LS14
BP
1 3
2
PLAT RETRACTED
LS15
BP
1 3
2PLAT RETRACTED
265
PLAT RETRACTED302
273G
273 G
[OPT.] LIFT W/O STABL'S
(OPEN @ HEIGHT)
LS15 BP
9
S1 S2
315F
321G
320F
319E
(STABL'S EXTENDED)
CR7
ALL MOTIONALARM [OPT.]
(BODY DOWN)
C
68
R16
COMPRESSOR [OPT.]
213
209
D 272
317
250 D
ALARM [OPT.] ALL MOTION
IGNLIFT
MODE
30 87
(DOWN CONTROLACTIVE)
CR9269
30 87A
28
28
28
- 12V
S11S10
S3 S4
S5 S6- 12V
THROTTLE
CR10MB
86 85
29 30 31
LIFT
LIFT
LIFT
33
33
34
UP INHIBIT
CR9MB
86 85
S7 S8
- 12V
MAIN BOX
MAIN BOX
31
32
UPPER
J3
J20 J19
J18
J17
DXMB
28
86 8533
THROTTLE INHIBIT
CR5MB
267
(THROTTLE INHIBIT)
87A
CR5
30
LOWER
J14
F126
COMPRESSOR INHIBIT
COMPRESSOR INHIBIT
COMPRESSOR INHIBIT
33AD5MB
D6MB
OIL OVERHEAT
87a30
CR17323
CR11273
30 87
PLATFROM
CR11MB
86 85
RETRACTED
PLATFROM
CR12MB
86 85
RETRACTED
CHASSIS
CHASSIS
Black
White
Rd/Wy Bd/Yl
Brown Black
Blue
THESE CONNECTIONS MADE AT UPPER CONTROLSWAS FOR PBU OPTION
REMOVE FOR ALL MOTION ALARM
RELOCATED FROM LINE 205
PTO REQUEST 0.2A
3.0A
4.0A
4.0A
4.0A
7.2A
7.2A
7.2A
4.0A4.0A
7.2A
4.0A
3.0A
0.2A
1.0A (?)
6.0A
6.0A
0.2A
0.2A
0.2A
0.2A
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MAINTENANCE2-5Page 10
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 7ELECTRICAL SCHEMATIC, OPTIONS - SHEET 5 OF 9
PLATFORM
HYDRAULIC
PLATFORMRETRACT
PLATFORM
HYDRAULICPUMP
COMPRESSORINHIBIT
EXTEND
ENABLE
PUMP
300 -
301 -
302 -
303 -
304 -
305 -
306 -
307 -
308 -
309 -
312 -
310 -
311 -
313 -
314 -
315 -
316 -
317 -
318 -
319 -
320 -
321 -
322 -
323 -
324 -
325 -
327 -
311
+12V
IGN+12V
-12V
-12V
DOWN
326 -
UC
COMPRESSOR
UCS-3 UCS-4
SWC
CH
PS2
CompressorLow Air Pressure
COMPRESSOR
CHCompressor Fan
CH
Compressor Solenoid
SCISSOR HEIGHTSC
LS16-2
BP
(PLAT. RETRACTED)
315
LS16 BP(PLAT. EXTENDED)
UC
GC
STABL. RETRACT
CLOSED WHEN HOT (140 F)
HYD OIL TEMP
TS1 MV
252
OIL OVERHEAT
R
LT9IP
HYD OIL OVERHEAT
BP
1 3
2 BP
1 3
2PLATF EXT
SOL9
PLATF RETR
SOL10
ELECTRIC
CON1
ELECT
CON1
-+
HYDRAULIC
HYDRAULICPUMP
PUMP
MB
MB
CC
CC
MV
EXTEND
RETRACT
PLATFORM
PC-1
PC-2
EXTEND
0RETRACT
310
SW21
SW21-A
SW21-B
SW23
M1
PC-3
PC-3
HYDR.PUMP
AUX PUMP
CC
CB4150A
MV-1 MV-2 MV-3
F251
256 PTOC
322H
RETRACT
GC-8
RETRACT
GC-1
SWXX-B
GC-7
EXTEND
GC-1
SWXX-A
PLATFORM 0
EXTEND
LT-10
LT-9
LT-1
F262
G266
H307
1
R12
4
(ENGINE RUNNING)
114
IGNLIFT MODE
+12V
44 44
45
46
MAIN BOX
MAIN BOX
LT2
BLACK
RED
BLACK
J24
16
319
87A
COMPRESSOR INHIBIT
CR8
30
CR8MB
J4 LT7
J21
J23
43
42
14
LIFT UP
E258
LIFT DOWN
PLATFORM EXTEND / RETRACT
COMPRESSOR INHIBIT
39
LIFT86 85
OIL OVERHEAT
MB36CR17
OIL OVERHEAT
YEL/GRN
CR12 275
30 87a
CHASSIS
CHASSIS
Black Green
WHT BLK
Rd/Wh Rd/Yl
Rd/Bl
Rd/Yl
N/A WITH ENGINE STOP; see line 202
3.0A
3.0A
0.5A
130A APPROX.
0.2A
1.5A
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SYSTEM SCHEMATICS 2-5Page 11
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 8ELECTRICAL SCHEMATIC, OPTIONS - SHEET 6 OF 9
ENGINERUNNING
ENGINERUNNING
[OPT.]
112 -
113 -
114 -
115 -
116 -
TRANSMISSIONOIL PRESS.
(ENGINE RUNNING)
PS1
309
159
221
IGNITION
101
EN
UC9 CC3
STOP
ON
START
UC10
MB
ENGINE STOP
108 -
109 -
112 -
110 -
111 -
STARTER
STARTERSW2
SW2-C
SW2-B
ENGINE RESTART
CB1 CR1
(IGNITION ON)
SW2-A UC
5
7
41
SW4
PLATFORM FLOODS
BP BP
BP
BP
BP
GC BP
PLATFORM FLOODLIGHTS
BODY INTERIORLIGHTS
REAR FLOODLIGHT
BEACONLIGHT
BEACONLIGHT
PLATFORM FLOODLIGHTS
BODY INTERIORLIGHTS
REAR FLOODLIGHT
LT2
LT3
LT4
LT5
TIMER SWITCH
INTERIOR LIGHTS[TIMER SWITCH IS STD.]
BEACON
SW5
SW7
REVERSE FLOOD
A107
SW5-A SW5-B
15 1615
35 40
152 -
153 -
154 -
155 -
156 -
157 -
158 -
159 -
1515A
41
FLASHER
LX
P
MB35 40
7
UC-1 UC-2
HOUR METER STOP
ENGINE STOP
104
110
1027
3-WAY SWITCHES[OPT.]
IGNITION
101MB
R12MB
MB
CB1 CR1
(IGNITION ON)
CR3
7 2
CR2
MB
110 MB
MB
D1
(ENGINE STOPPED)
R11 R11
7 28 6
+12V IGN
IGN+12V
8
IGN
IGN
RELOCATE THIS WIRE FROM
IGN TO 8
CB240A MB
(BODY DOWN)LIGHTS
R15211
1 4
8730
(IGN. ON)
CR3116
8
LT-5
LT-5A
OPTIONS
OPTION FOR BEACON ON WHEN ENGINE RUNNING (CONTINENTAL)NOTE: For this option, the body interior lights and platform floods must bothbe on timer switches. The rear flood must be either on a timer or be a reverse light(Continental wires the rear flood as a reverse light).
OPTION FOR ENGINE RESTART FROM UPPER CONTROLS
NOTE: REMOVE STANDARD JUMPER
FROM IGN TO TERM 5
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MAINTENANCE2-5Page 12
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 9ELECTRICAL SCHEMATIC, OPTIONS - SHEET 7 OF 9
[THIS SWITCH REPLACES STD.JUMPER WIRE FROM IGN TO 17]
6
203
IPLS3
(CLOSED WHEN MICO BRAKE SET)
MICO [OPT]
120 - PARK BRAKE
125
6
THIS WIRE INTERNALTO MICO CONTROL UNIT
-12V
LOWER E-STOP UPPER E-STOPLIFT MODE[LIFT/DRIVE]
SW8
LIFT MODEGC
203 -
204 -
UCGCSW9 SW10
221
GC5 GC6 UC1 UC2
-12V
NEUTRAL INDICATION
TCM[ALLISON TRANSMISION]
(GROUNDED IN NEUTRAL)
CC4EN
CC6-B
CC6-A
124 -
125 -
126 -
NEUTRALLOCK
NOTE: WHEN CIRCUIT IS OPEN TRANSMISSION IS LOCKED IN NEUTRAL
11
12
11
12
IGN+12V
- 12V
42
(GROUND POWER CONNECTED)
CR20
GROUNDPOWERCONNECTED
GROUND POWERCONNECTED
R
LTX
CR20
125
GP
IP GROUNDPOWERWARNINGLIGHT
217 -
GROUND POWER
315 -
316 -
120VAC WHENGROUND POWER
CONNECTED
CR20
(GROUND POWER CONNECTED)
316
217
316
+120VAC GROUND
41 42
3433
A1 A2
42
+12V
306 -
BPPS17 PLATFORM
EXTEND
-12V
BPPS17-A
SW21
SW21-A EXTEND
AU-1 AU-4
PLATF INHIBIT
SOL9
PLATF EXT
BP1 3
2
1 3
2
PLATF INHIBIT
LT-1
MBR13
7 2
IGN
+12V
30
R13
87 8 6
CR4 CR6
(BRAKE SET)(NEUTRAL) LIFT MODE
86 85120118
MBIGN
17
18 191817A17
IGN
+12V
(PARK BRAKE SET)
R14
(STABS STOWED)
120 207R13
681 4
IGN
MODELIFT
IGN
J22
J6
14J23
J25
OPTION FOR MICO BRAKE
OPTION FOR LIFT/DRIVE SWITCH
OPTION FOR NO VEHICLE MOVEMENT (NEUTRAL LOCK) WHEN GROUND POWER CONNECTED
OPTIONS
OPTION FOR PLATFORM EXTEND INHIBIT
1.5A
3.0A
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SYSTEM SCHEMATICS 2-5Page 13
ML50-30 MAINTENANCE LIFT TESCO EQUIPMENT LLC
Figure 10ELECTRICAL SCHEMATIC, TABLES OF VEH. CONNECTIONS - SHEET 8 OF 9
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MAINTENANCE2-5Page 14
TESCO EQUIPMENT LLC ML50-30 MAINTENANCE LIFT
Figure 11ELECTRICAL SCHEMATIC, TABLES OF VEH. CONNECTIONS
DPDT & SPDT RELAY WIRING - SHEET 9 OF 9
Mar. 17
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