Nilfisk-Advance ConvertaMAX 28 User manual

5/00 revised 12/02 Form Number
56043057
ConvertaMAX™28/34
I-MAX™28HD/34HD
BA 750/850
SERVICE MANUAL
Advance MODELS (Active 56396015, 56396019,
56396016, 56396020) (Obsolete 56396000,
56397200, 56396001, 56397201)
Nilfisk MODELS (Active 56396017, 56396018)
(Obsolete 56396002, 56396003)

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FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
™
28HD/34HD, BA 750/850
TABLE OF CONTENTS
GENERAL INFORMATION .................................................................................................................................................. 2
SAFETY INSTRUCTIONS....................................................................................................................................................3
SPECIFICATIONS & MAINTENANCE ............................................................................................................................. 4-6
PM CHECKLIST ...................................................................................................................................................................7
KNOW YOUR MACHINE ............................................................................................................................................... 9-13
SOLUTION SYSTEM ................................................................................................................................................... 14-19
FUNCTIONAL OVERVIEW .............................................................................................................................................. 14
TROUBLESHOOTING GUIDE & SYSTEM MAINTENANCE ........................................................................................... 15
SOLUTION SOLENOID VALVE REMOVAL (BEFORE SN BREAK) ...............................................................................15
SOLUTION VALVE DISASSEMBLY AND CLEANING (BEFORE SN BREAK) ...............................................................16
SOLUTION FILTER REMOVAL (BEFORE SN BREAK) ..................................................................................................16
SOLUTION FLOW CONTROL VALVE REMOVAL (BEFORE SN BREAK ......................................................................16
SOLUTION SOLENOID VALVE REMOVAL (AFTER SN BREAK) ..................................................................................18
SOLUTION VALVE DISASSEMBLY AND CLEANING (AFTER SN BREAK) ..................................................................18
SOLUTION FILTER REMOVAL (AFTER SN BREAK) .....................................................................................................18
SOLUTION FLOW CONTROL VALVE REMOVAL (AFTER SN BREAK) ........................................................................19
SCRUB BRUSH SYSTEM............................................................................................................................................ 20-24
GENERAL BRUSH SYSTEM FUNCTIONAL OVERVIEW ...............................................................................................20
SCRUB BRUSH SYSTEM TROUBLESHOOTING .......................................................................................................... 22
28/34 BRUSH DECK REMOVAL .....................................................................................................................................23
SCRUB BRUSH LIFT ACTUATOR REMOVAL................................................................................................................ 23
SCRUB BRUSH MOTOR/GEARBOX REMOVAL ............................................................................................................ 23
RECOVERY SYSTEM.................................................................................................................................................. 25-27
FUNCTIONAL OVERVIEW .............................................................................................................................................. 25
VACUUM/RECOVERY SYSTEM MAINTENANCE CHECKLIST .....................................................................................26
TROUBLESHOOTING GUIDE ......................................................................................................................................... 26
MAINTENANCE OF FLOAT CAGE AND FLOAT DUCT ................................................................................................. 26
VACUUM MOTOR REMOVAL .........................................................................................................................................26
RECOVERY TANK REMOVAL ........................................................................................................................................ 26
SQUEEGEE SYSTEM.................................................................................................................................................. 28-31
SQUEEGEE SYSTEM LIFT MOTOR OVERVIEW ..........................................................................................................28
OPERATIONAL OVERVIEW OF THE SQUEEGEE LIFT MOTOR REVERSE FUNCTION ............................................28
REVERSE SWITCH INSTALLATION AND ADJUSTMENT .............................................................................................29
SQUEEGEE LIFT ACTUATOR MOTOR REMOVAL .......................................................................................................30
SQUEEGEE TOOL BLADE(S) REPLACEMENT .............................................................................................................30
SQUEEGEE ADJUSTMENT ............................................................................................................................................ 30
WHEEL DRIVE SYSTEM ............................................................................................................................................. 32-43
GENERAL FUNCTIONAL OVERVIEW ...................................................................................................................... 32-33
TROUBLESHOOTING GUIDE ................................................................................................................................... 34-36
PARKING BRAKE OPERATION ......................................................................................................................................37
BRAKE ASSEMBLY REMOVAL ......................................................................................................................................37
BRAKE CALIPER ADJUSTMENT ....................................................................................................................................37
DRIVE MOTOR REMOVAL.............................................................................................................................................. 37
DRIVE WHEEL REMOVAL .............................................................................................................................................. 38
CHAIN REMOVAL AND ADJUSTMENT .................................................................................................................... 38-39
POTENTIOMETER (5K) TESTING AND REMOVAL (FOR MACHINES BUILT BEFORE DEC. 1 2000) ....................... 40
POTENTIOMETER INSTALLATION AND ADJUSTMENT (MACHINES BEFORE DEC. 1, 2000) ................................. 41
POTENTIOMETER (5K) TESTING AND REMOVAL (FOR MACHINES BUILT AFTER DEC. 1, 2000) ......................... 42
POTENTIOMETER INSTALLATION AND ADJUSTMENT (MACHINES AFTER DEC. 1, 2000) .............................. 42-43
POTENTIOMETER (100K) WHEEL DRIVE SPEED LIMIT TESTING (ALL MODELS) ...................................................43
revised 12/02

FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
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28HD/34HD, BA 750/850
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1
TABLE OF CONTENTS
ELECTRICAL SYSTEM................................................................................................................................................ 44-67
BATTERIES / CHARGERS .............................................................................................................................................. 44
INSTALL THE BATTERIES ..............................................................................................................................................44
DESCRIPTION OF LOW VOLTAGE CUTOUT FEATURE ..............................................................................................44
DESCRIPTION OF THE BATTERY CONDITION INDICATORS .....................................................................................45
BATTERY CHARGING, MAINTENANCE AND TESTING ...............................................................................................45
ACTUATOR DRIVE NUT ADJUSTMENT .................................................................................................................. 46-47
CURTIS SPEED CONTROL ...................................................................................................................................... 48-49
FUNCTIONAL OVERVIEW OF MAIN CONTROL BOARD ..............................................................................................50
MAIN CONTROL BOARD TROUBLESHOOTING GUIDE ...............................................................................................50
MAIN CONTROLLER ERROR CODES ..................................................................................................................... 50-52
MAIN CONTROLLER DIAGNOSTIC SERVICE TEST MODE ................................................................................... 53-56
MAIN CONTROL BOARD SPECIAL PROGRAM OPTIONS ..................................................................................... 57-62
ELECTRICAL COMPONENT LOCATION ........................................................................................................................ 63
WIRING DIAGRAM (OBSOLETE MODELS) ...................................................................................................................64
WIRING SCHEMATIC (OBSOLETE MODELS) ...............................................................................................................65
WIRING DIAGRAM (ACTIVE MODELS) ..........................................................................................................................66
WIRING SCHEMATIC (ACTIVE MODELS) .....................................................................................................................67
Note: All references to right, left, front, or rear in this manual are as seen from the operator’s stand-point.
revised 12/02

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FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
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28HD/34HD, BA 750/850
INTRODUCTION
This manual will help you get the most from your ConvertaMAX™28/34, I-MAX™28HD/34HD & BA 750/850. Read it thoroughly before servicing
the machine.
Note: Bold numbers in parentheses indicate an item illustrated on pages 9-10.
PARTS AND SERVICE
Repairs, when required, should be performed by your Authorized Nilfisk-Advance Service Center, who employs factory trained service personnel,
and maintains an inventory of Nilfisk-Advance original replacement parts and accessories.
Call the NILFISK-ADVANCE DEALER named below for repair parts or service. Please specify the Model and Serial Number when discussing
your machine.
(Dealer, affix service sticker here.)
NAME PLATE
The Model Number and Serial Number of your machine are shown on the Nameplate on the machine. This information is needed when ordering
repair parts for the machine. Use the space below to note the Model Number and Serial Number of your machine for future reference.
MODEL NUMBER
SERIAL NUMBER
TRANSPORTING THE MACHINE
CAUTION!
Before transporting the machine on an open truck or trailer, make sure that . . .
•The machine is tied down securely - see tie-down locations in Know Your Machine section.
• All access doors and covers are secured (tape and strap as needed).
TOWING
CAUTION!
If the machine must be towed or pushed, make sure the Master On/Off Key Switch (20) is in the OFF position and do not move the
machine faster than a normal walking pace (2-3 mph, 3-5kph) and for short distances only.
OTHER MANUALS AVAILABLE FOR YOUR MACHINE
The following manuals are available from the Nilfisk-Advance Literature Service Department (order according to model name, number and
machine’s serial number):
• A Parts List and Operation Manual are available for each machine (request by your machine’s “Model Number” and “Serial Number”).
• Operation Manuals for the BA 750 / BA 850 are multi-language; (Danish, Norwegian, Swedish, Finnish), (English, German, French,
Netherlands) or (Spanish, Portuguese, Italian, Greek)
GENERAL INFORMATION
revised 12/02

FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
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28HD/34HD, BA 750/850
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3
CAUTIONS AND WARNINGS
SYMBOLS
Nilfisk-Advance uses the symbols below to signal potentially dangerous conditions. Read this information carefully and take the
necessary steps to protect personnel and property.
DANGER!
Is used to warn of immediate hazards that will cause severe personal injury or death.
WARNING!
Is used to call attention to a situation that could cause severe personal injury.
CAUTION!
Is used to call attention to a situation that could cause minor personal injury or damage to the machine or other property.
GENERAL SAFETY INSTRUCTIONS
Specific Cautions and Warnings are included to warn you of potential danger of machine damage or bodily harm.
WARNING!
•This machine should only be used by properly trained and authorized persons.
•Keep sparks, flame and smoking materials away from batteries. Explosive gases are vented during normal operation.
•Charging the batteries produces highly explosive hydrogen gas. Charge batteries only in well-ventilated areas, away from open
flame. Do not smoke while charging the batteries.
•Remove all jewelry when working near electrical components.
•Turn the key switch off (O) and disconnect the batteries before servicing electrical components.
•Never work under a machine without safety blocks or stands to support the machine.
•Do not dispense flammable cleaning agents, operate the machine on or near these agents, or operate in areas where flammable
liquids exist.
•Do not clean this machine with a pressure washer.
•Do not operate this machine on ramps or inclines of more than a 9.5 degree angle.
CAUTION!
•This machine is not approved for use on public paths or roads.
•This machine is not suitable for picking up hazardous dust.
•Use care when using scarifier discs and grinding stones. Nilfisk-Advance will not be held responsible for any damage to floor
surfaces caused by scarifiers or grinding stones.
•When operating this machine, ensure that third parties, particularly children, are not endangered.
•Before performing any service function, carefully read all instructions pertaining to that function.
•Do not leave the machine unattended without first turning the key switch off (O), removing the key and securing the machine’s
parking brake.
•Turn the key switch off (O) before changing the brushes and before opening any access panels.
•Take precautions to prevent hair, jewelry, or loose clothing from becoming caught in moving parts.
•Use caution when moving this machine in below freezing temperature conditions. Any water in the solution or recovery tanks
or in the hose lines could freeze.
• The batteries must be removed from the machine before the machine is scrapped. The disposal of the batteries should be safely
done in accordance with your local environmental regulations.
SAVE THESE INSTRUCTIONS
GENERAL INFORMATION

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FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
™
28HD/34HD, BA 750/850
Model designation: (A)=ConvertaMAX 28 & BA 750, (B)=I-MAX 28HD, (C)=BA 850, (D)=ConvertaMAX 34, (E)=I-MAX 34HD
General Specifications
ABCDE
Machine Length (English) 64 in. 65 in. 67.5 in. 67.5 in. 67.5 in.
Metric 163cm 165cm 172 cm 172 cm 172 cm
Machine Width with Squeegee (English) 36.25 in. 36.25 in. 45 in. 45 in. 45 in.
Metric 92cm 92cm 114cm 114cm 114cm
Machine Width w/out Squeegee (English) 30 in. 30 in. 30 in. 35.5 in. 35.5 in.
Metric 76cm 76cm 76cm 90cm 90cm
Machine Height 44 in. (112cm) 44 in. (112cm) 44 in. (112cm) 44 in. (112cm) 44 in. (112cm)
Machine Net Weight* (English) 495 lbs. 535 lbs. 556 lbs. 579 lbs. 619 lbs.
Metric 225 kg 243 kg 252 kg 263 kg 281 kg
Machine Gross Weight** (English) 1,100 lbs. 1,140 lbs. 1,120 lbs. 1,350 lbs. 1,435 lbs.
Metric 499 kg 518 kg 508 kg 612 kg 651 kg
Cleaning Width (scrubbing path) (English) 28 in. 28 in. 33.5 in. 33.5 in. 33.5 in.
Metric 71cm 71cm 85 cm 85 cm 85 cm
Coverage Rate Per Hour (theory) (English) 37,100 ft237,100 ft244,388 ft244,388 ft244,388 ft2
Metric 3,447m23,447m24,124m24,124m24,124m2
Coverage Rate Per Hour (actual) (English) 16,900 ft216,900 ft220,475 ft220,475 ft220,475 ft2
Metric 1,570m21,570m21,902m21,902m21,902m2
Brush Diameter (qty of 2) (English) 14.5 in. 14.5 in. 17 in. 17 in. 17 in.
Metric 37cm 37cm 43cm 43cm 43cm
Brush Speed (RPM) 220 220 220 220 220
Brush Pressure Variable, (English) 25-250 lbs. 25-300 lbs. 25-250 lbs. 25-250 lbs. 25-300 lbs.
Metric 11-113 kg 11-136 kg 11-113 kg 11-113 kg 11-136 kg
Solution Tank Capacity 24 gal. (91l.) 24 gal. (91l.) 24 gal. (91l.) 30 gal. (114l.) 30 gal. (114l.)
Recovery Tank Capacity 24 gal. (91l.) 24 gal. (91l.) 24 gal. (91l.) 30 gal. (114l.) 30 gal. (114l.)
Vacuum Water Lift (Sealed) 56 in. 56 in. 56 in. 68 in. 68 in.
(Open Hole Adapter 1") 9 in. 9 in. 9 in. 13 in. 13 in.
Sound power level
as per ISO 3744 (at operator) 74 dB(A) 74 dB(A) 74 dB(A) 74 dB(A) 74 dB(A)
Transport Speed (Fwd. Maximum) 265 FPM 265 FPM 265 FPM 265 FPM 265 FPM
Metric 81 m/min 81 m/min 81 m/min 81 m/min 81 m/min
Transport Speed (Rev. Maximum) 140 FPM 140 FPM 140 FPM 140 FPM 140 FPM
Metric 43 m/min 43 m/min 43 m/min 43 m/min 43 m/min
Power Source (Batteries) STD (4) 6V/238AH (4) 6V/238AH (4) 6V/238AH (6) 6V/238AH (6) 6V/238AH
Battery Weight (each) 66lbs. (29.9kg) 66lbs. (29.9kg) 66lbs. (29.9kg) 66lbs. (29.9kg) 66lbs. (29.9kg)
Battery Compartment Size
Height (Max.) 13 in. (33cm) 13 in. (33cm) 13 in. (33cm) 15 in. (38 cm) 15 in. (38 cm)
Width (Max.) 15 in. (38cm) 15 in. (38cm) 15 in. (38cm) 21.37 in. (54 cm) 21.37 in. (54 cm)
Length (Max.) 24 in. (61cm) 24 in. (61cm) 24 in. (61cm) 23.5 in. (59 cm) 23.5 in. (59 cm)
Battery Chargers – see Electrical System Battery Section
Wheel Drive Motor (all models) .75 hp, 560 watt .75 hp, 560 watt .75 hp, 560 watt .75 hp, 560 watt .75 hp, 560 watt
Vacuum Motor (all models) .75 hp, 570 watt .75 hp, 570 watt .75 hp, 570 watt .75 hp, 570 watt .75 hp, 570 watt
Brush Drive Motors (2 each) .75 hp, 560 watt 1 hp, 746 watt .75 hp, 560 watt .75 hp, 560 watt 1 hp, 746 watt
Machine Current (Average) 65 Amps 81 Amps 65 Amps 60 Amps 65 Amps
*Net Weight: Standard machine without options, empty solution and recovery tanks, without removable scrub brushes and no batteries installed.
**Gross Weight: Standard machine without options, full solution tank and empty recovery tank, with removable scrub brushes and 305 AH batteries.
SPECIFICATIONS

FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
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28HD/34HD, BA 750/850
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5
SPECIFICATIONS
TOP VIEW
SIDE VIEW
Length
Height
Width
Squeegee
Width

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FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
™
28HD/34HD, BA 750/850
MAINTENANCE
MAINTENANCE SCHEDULE
Maintenance intervals given are for average operating conditions. Machines used in severe operational environments may require
service more often.
MAINTENANCE ITEM Daily Weekly Monthly Yearly
Charge the Batteries X
Drain / Clean and Check Tanks & Hoses X
Check / Clean / Rotate the Brushes/Pads X
Check / Clean / Adjust the Squeegee X X
Check / Clean Vacuum Shut-Off Float X
Check Each Battery Cell’s Water Level X
Inspect and Clean Solution Filter X
*Check Parking Brake For Wear & Adjustment X
Lubricate the Machine X
**Check Motor(s) Carbon Brushes X
*If machine is equipped with the optional parking brake.
**Note: See the individual machine system sections for maintenance information.
WARNING!
Turn the key switch off and disconnect the battery before servicing the machine.
• Check vacuum motor carbon brushes (Qty 2) once a year or after 300 operating hours.
• Check brush and wheel drive motor(s) carbon brushes (Qty 4 per motor) once a year or after 500 operating hours.
• The original (new) length of each carbon brush is 1" (25.4mm) on all machine models 24 volt and 36 volt motors.
• Replace carbon brushes when shorter than 3/8" (9.5mm) to obtain the same motor efficiency as new brushes.
IMPORTANT!
Motor damage resulting from failure to service the carbon brushes is not covered under warranty. See the Limited Warranty
Statement.
BATTERIES AND CHARGERS
Attention: See the electrical system manual section for battery installation, battery maintenance and charger system requirements.
LUBRICATING THE MACHINE
Once a month, pump a small amount of grease into each grease fitting on the machine until grease seeps out around the bearings.
Grease fitting locations are:
• Rear Caster Wheel Axle & Swivel (2) per Assembly
Once a month, apply light machine oil to lubricate the:
• Drive Chain
• Squeegee Tool Adjustment Knob, Wheels & Rollers
• Pivot Points For the Squeegee & Scrub Brush Linkage
revised 12/02

FORM NO. 56043057 / ConvertaMAX
™
28/34, I
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MAX
™
28HD/34HD, BA 750/850
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7
Copyright 2001 Nilfisk-Advance. 8/09/01
Advance ConvertaMAX 28/34, I-MAX 28HD/34HD
Models 56396000, 56397200, 56396001, 56397201, 56396015, 56396019, 56396016, 56396020
Nilfisk BA 750/850 Models 56396002, 56396003, 56396017, 56396018
PM Checklist
Defect Codes
Customer A needs adjustment
Bbinding
Address C dirty or contaminated
Ddamaged, bent or torn
City St Zip Lleaks
Mmissing
Model Serial Hours Wworn out
Ref
OPERATIONAL INSPECTION ITEMS
OK
Defect Codes
(circle)
Does
Not
Work
1 Drive Paddle Operation (check for Fwd/Rev Drive & any neutral creep) A B D
2 Drive System Performance (Speed Changes Min/Max) noisy sluggish
3 Scrub System (Raise/Lower, Brush Motor On/Off, Brush install & Remove Feature) A B D
4 Scrub Brush (pressure settings Normal & Heavy) A B
5 Squeegee System (Raise/Lower & Squeegee Tool pickup Performance) A B D
6 Vacuum Performance (Sealed water lift 56" for 24V, 68” for 36V and 1- inch open
hole adapter 9” for 24V, 13” for 36V)
CLW
7 Solution Control (On/Off Manual /Auto and Flow Volume Min/Max) A B L
8 Battery Charger (Auto turn ON & OFF) D
Ref
VISUAL INSPECTION ITEMS
Comments OK
Defect Codes
(circle)
Does
Not
Work
9 Scrub Brushes, check for wear and rotate DMW
10 Scrub Brush Motors, check for carbon brush wear 500 Hours B C W
11 Scrub Brush Motors, check gearboxes B D L
12 Brush Drive Plate Retainer Clips & flex couplers C D M
13 Scrub Deck Skirts and Side Wheel(s) D M W
14 Solution Solenoid Valve C D L W
15 Solution Flow Control Valve and Linkage A B D W
16 Solution Tank, Delivery Hoses & Filter Clean filter screen C L
17 Vacuum Motor Carbon Brushes (wear limit 3/8”) 300 Hours B C W
18 Vacuum Motor Gaskets CDL
19 Vacuum Float Ball & Cage Assembly Clean float C D M
20 Recovery Tank Cover Gasket L M W
21 Recovery Tank Drain Hose & Cap C D L
22 Squeegee Pick-Up Hose Back flush C D L
23 Squeegee Tool & Blades (clean & rotate) A D W
24 Squeegee Tool Wheels (lubricate) 2 side and 2 floor A D W
25 Battery Condition (load test, clean & water) C W
26 Front Drive Wheel Motor Check Carbon Brushes 500 Hours B C W
27 Front Drive Tire tread wear W
28 Drive wheel Motor Chain (Lubricate and tension) A B C W
29 Rear chassis Caster Wheels (Lubricate) tread wear W
NOTE: For additional service information see service manual form number 56043057 and
operators manual form numbers 56041463, 56041464, 56041465 / 56041479 / 56041515, 56041516,
56041517.
WORK COMPLETED BY: ACKNOWLEDGED BY:
revised 12/02

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FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
™
28HD/34HD, BA 750/850
BLANK
revised 12/02

FORM NO. 56043057 / ConvertaMAX
™
28/34, I
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MAX
™
28HD/34HD, BA 750/850
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9
1 Solution Tank Fill
2 Recovery Tank & Cover
3 Drive Paddle
4 Solution Drain Hose / Level Indicator
5 Recovery Drain Hose
6 Squeegee Adjustment Bolt
7 Squeegee Blade Latch
8 Squeegee
9 Battery Charger Connector
10 Solution Flow Control Knob
11 Speed Limit Control Knob
12 Wheel Drive Circuit Breaker (40 Amp)
13 Control Circuit Circuit Breaker (10 Amp)
14 Brush Deck
15 Operator Control Handle
16 Operator Hand Brake
KNOW YOUR MACHINE
1
1
2
3
4
5
7
8
9
10
11
12
13
14
15
16
Tie Down, Front
Tie Down, Rear
6
revised 12/02

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FORM NO. 56043057 / ConvertaMAX
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28/34, I
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MAX
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28HD/34HD, BA 750/850
KNOW YOUR MACHINE
17 18 19 20
21
22
23
24
25
26
27
28
29
30
32
31
33
34
36
35
CONTROL PANEL
17 Battery Condition Indicator
18 Hourmeter/Status Display
19 Main Power Indicator
20 Master On/Off Key Switch
21 Solution System Indicator
22 Solution System Fault Indicator
23 Solution Button
24 Vacuum System Fault Indicator
25 Vacuum Button
26 Vacuum System Indicator
27 Heavy Scrub Button
28 Heavy Scrub Mode Indicator
29 Normal Scrub Button
30 Normal Scrub Mode Indicator
31 Scrub Off Button
32 Scrub Mode Off Indicator
33 Brush Remove Button
34 Brush Remove Indicator
35 Brush Install Button
36 Brush Install Indicator
revised 12/02

FORM NO. 56043057 / ConvertaMAX
™
28/34, I
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MAX
™
28HD/34HD, BA 750/850
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11
FUNCTIONAL DESCRIPTION OF CONTROLS:
Solution Tank Fill (1) – Open to fill the solution tank, use non-foaming chemicals only. Capacity is 24 or 30 gallons (90 or 113 Liters) depending
on model.
Recovery Tank & Cover (2) – Rear of tank is entry for waste water into tank. Capacity is 24 or 30 gallons (90 or 113 Liters) depending on model.
Cover also houses float ball, which shuts off vacuum port to vac motor when tank is full.
Drive Paddle (3) – Located on top at the rear of the machine, the operator can make the machine go forward by pushing forward on it, or reverse
by pulling backward on it. The speed is variable depending on how far forward or backward the paddle is moved. When the brush head is in the
“DOWN” position, the brushes, vacuum and solution will operate when the drive is engaged in either direction, but will stop after the machine is
stationary for 3 seconds.
Solution Drain Hose / Level Indicator (4) – Used to empty the solution tank and show current level of solution in tank, graduations are marked
on the side of the solution tank next to the hose.
Recovery Drain Hose (5) – Used to empty the recovery tank.
SqueegeeAdjustment Bolt(6)– Used to adjust the tilt of the squeegee. Turn bolt clockwise to tilt the squeegee backwards and counter-clockwise
to tilt it forward.
Squeegee Blade Latch (7) – Holds rear squeegee blade and straps in place, release to replace rear blade.
Squeegee (8) – Picks up solution after scrubbing.
Battery Charger Connector (9) – Plug battery charger into this port to charge batteries.
SolutionFlowControl Knob(10)– Turn this dial to the right to decrease solution flow to the floor. Turn to the left, to increase the amount of solution
flow to the floor. When the Drive Paddle (3) is released from either forward or reverse travel, the solution flow will stop automatically, and resume
when the drive is engaged.
Speed Limit Control Knob (11) – The Speed Limit Control Knob is used to adjust the maximum speed in both forward or reverse.
WheelDrive CircuitBreaker(12) – Provides overload protection to machine’s wheel drive motor. If it trips, it will pop out. To reset, wait one minute
and press the button back in. If any breaker trips repeatedly, have the machine serviced.
Control Circuit Circuit Breaker (13) – Provides overload protection. If it trips, it will pop out. To reset, wait one minute and press the button back
in. If any breaker trips repeatedly, have the machine serviced.
Brush Deck (14) – Contains brush drive motors and brushes.
Operator Control Handle (15) – Operator holds onto this to control the machine.
Operator Hand Brake (16) – Use to prevent machine from rolling.
FUNCTIONAL DESCRIPTION OF CONTROL BUTTONS:
The controls were designed with one touch operation in mind. For single pass scrubbing the user can simply depress one button and all systems
on the machine will be ready to go.
For most single-pass scrubbing operations, the operator should only need to use the middle three buttons on the control panel. These are the
Scrub Mode Off, Normal Scrub, and Heavy Scrub buttons. For this reason these buttons are outlined in bright white on the control panel while
the other buttons are outlined in gray.
Solution Button (23) - This button is used to select the mode of operation for the solution system. There are 3 modes of operation for this system.
The modes are OFF, AUTO, MOMENTARY ON. Following is a description of each mode and how they are selected.
OFF MODE: In this mode the solution flow is turned off. As mentioned below, when a scrub mode is selected, the solution system will be placed
in the AUTO mode. If it is desired to scrub without dispensing solution, the solution can be turned off by pressing this button.
AUTO MODE: This mode is automatically selected when a scrub mode is selected. In this mode the solution flow will be turned on whenever
forward or reverse direction is selected via the Drive Paddle (3). The solution flow will be turned off otherwise.
MOMENTARY ON MODE: This mode can only be selected when the scrub mode is OFF. Solution can be dispensed by pressing and holding
the solution button. Solution will be dispensed for as long as the button is held. This is for pre-wetting the floor prior to scrubbing.
Vacuum Button (25) - This button is used to select the mode of operation for the vacuum/squeegee system. There are 3 modes of operation for
this system. These modes are OFF, AUTO, ON. Following is a description of each mode and how they are selected.
OFFMODE: In this mode the vacuum is off and the squeegee is in the up position. As mentioned below, when a scrub mode is selected, the vacuum
system will be placed in the AUTO mode. If it is desired to double-scrub (scrub without recovering the solution) the vacuum system can be turned
off by pressing this button.
AUTO MODE: This mode is automatically selected when a scrub mode is selected. In this mode the squeegee will be in the down position unless
the reverse direction is selected via the Drive Paddle. The vacuum will turn on if either direction is selected. While in this mode the vacuum will
remain on for 10 seconds after the Drive Paddle returns to the neutral position. This is so that the solution in the squeegee and hose can be drawn
into the tank. This mode can be selected independently of the scrub mode by pressing and releasing the vacuum button.
ON MODE: In this mode the squeegee will remain in the UP position and the vacuum will be on regardless of the Drive Paddle (3) position. This
mode is selected by pressing and holding the Vacuum Button (25) for approximately 1.5 seconds. The vacuum mode must first be OFF before
enteringthismode. Thismodeisincludedintheeventan external wand is to be used with this machine or if the operator wants to clean the squeegee
using the vacuum hose.
KNOW YOUR MACHINE
revised 12/02

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FORM NO. 56043057 / ConvertaMAX
™
28/34, I
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MAX
™
28HD/34HD, BA 750/850
Heavy Scrub Button (27) - Pressing the heavy scrub button will enable the scrub system and set the scrub pressure to the last selected value
for the heavy scrub mode. The status display will momentarily display the scrub pressure setting. This is indicated by “PA” followed by a number.
Subsequent presses of the heavy scrub button will step the pad pressure setting through the allowable range up to the maximum value programmed
for the heavy scrub mode. Once the maximum value is reached the pressure setting will step back to (normal scrub limit + 1). The factory default
maximum for the normal scrub mode is 9 (commercial) or 12 (industrial). The following will occur when this button is pressed:
• The scrub deck will be lowered
• The vacuum and solution systems will be enabled (vacuum and solution modes = AUTO)
• As soon as a direction is commanded by the Drive Paddle (3) (forward or reverse) the brushes will start turning and the vacuum will turn
on.
Normal Scrub Button (29) - Pressing the normal scrub button will enable the scrub system and set the scrub pressure to the last selected value
for the normal scrub mode. The status display will momentarily display the scrub pressure setting. This is indicated by “PA” followed by a number.
Subsequent presses of the normal scrub button will step the pad pressure setting through the allowable range up to the maximum value
programmed for the normal scrub mode. Once the maximum value is reached the pressure setting will step back to 1. The factory default maximum
for the normal scrub mode is 4. The following will occur when this button is pressed:
• The scrub deck will be lowered
• The vacuum and solution systems will be enabled (vacuum and solution modes = AUTO)
• As soon as a direction is commanded by the Drive Paddle (3) (forward or reverse) the brushes will start turning and the vacuum will turn
on.
Scrub Off Button (31) - Pressing this button when the unit is in a scrub mode will cause the following to occur:
• The scrub brushes will turn off
• The scrub deck will raise to the UP position
• The solution flow will be stopped
• The first time that this button is pressed, the vacuum/squeegee system will NOT be turned off. This is so that any remaining water may be
picked up without having to turn the vacuum back on. If this button is pressed a second time (pressed after the scrub mode has been turned
off) the squeegee will raise and the vacuum will shut off after a 10 second delay.
Brush Remove Button (33) – To remove the brushes from the machine, have the machine stationary and the Brush Deck (14) in the “RAISED”
position. The Brush Remove Indicator (34) will be yellow when it is okay to activate the remove feature, otherwise it will be off.
• Press and release the pad/brush remove button. The Brush Remove Indicator (34) will turn green to show that the remove process is
activated.
• The scrub motor will run for a brief period and then stop abruptly. This should cause the pads/brushes to drop off of the drive lugs.
Brush Install Button (35) – Have the machine stationary and the Brush Deck (14) in the “RAISED” position. The Brush Install Indicator (36) will
be yellow when it is okay to activate the install feature, otherwise it will be off.
• Place the pads/brushes under the scrub deck so that the pads/brushes are centered under the drive lugs.
• Press and release the pad/brush install button. The Brush Install Indicator (36) will turn green to show that the install process is activated.
• The scrub deck will lower and the scrub motors will run momentarily to engage the pads/brushes. If the pads/brushes do not engage fully,
press and hold the install button to activate the scrub motors.
• To scrub, press either the Normal (29) or Heavy Scrub Button (27).
• To raise the scrub deck, press the Scrub Off Button (31).
DESCRIPTION OF INDICATORS ON THE CONTROL PANEL:
In general, the following guidelines apply to the control panel indicators:
A steady red indicator means that the function is inhibited for some reason.
A flashing red indicator means that a fault has occurred in the particular system. An example of this would be an over-current fault.
A yellow indicator means that the particular function has been enabled but is not currently on. For example, if a scrub mode is selected and the
Drive Paddle (3) is in neutral, the scrub system, vacuum, and solution indicators will all be yellow indicating that the systems are enabled and ready
to turn on when the Drive Paddle (3) is moved to forward or reverse.
A green indicator means that the particular system is on.
A flashing green indicator means that the particular system is in a delayed-off condition. An example of this is when a scrub mode is selected and
the Drive Paddle (3) goes from forward or reverse to neutral. When this happens the vacuum indicator will flash green indicating that the vacuum
is still on but that it will be turning off after the delay period.
Main Power Indicator (19):
• This indicator will be GREEN when the key switch is ON.
• This indicator will flash RED if there is a system fault that requires turning the Master ON/OFF Key Switch (20) off to reset.
• This indicator will flash fault codes from the Curtis Speed Control if a fault exists. This will be accompanied by an “Err03” indication on the Hourmeter/Status
Display (18).
KNOW YOUR MACHINE
revised 12/02

FORM NO. 56043057 / ConvertaMAX
™
28/34, I
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MAX
™
28HD/34HD, BA 750/850
-
13
KNOW YOUR MACHINE
Solution System Indicator (21):
• This indicator will be YELLOW if the solution system is in the AUTO mode and the Drive Paddle (3) is in the neutral position. This indicates that the solution
system is enabled but the solution flow is currently off.
• This indicator will be GREEN if the solution system is in the AUTO mode and the Drive Paddle (3) is in the forward or reverse position. It will also be GREEN
if the solution system is in the MOMENTARY ON mode. This indicates that the solution flow is currently on.
• This indicator will be OFF if the solution system is in the OFF mode.
Solution System Fault Indicator (22):
• This indicator will flash red if there is a fault in the solution system. This will be accompanied by an error indication on the Hour Meter / Status Display (18).
Vacuum System Fault Indicator (24):
• This indicator will flash red if there is a fault in the vacuum or squeegee systems. This will be accompanied by an error indication on the Hour Meter / Status
Display (18).
• This indicator will be RED and the Hour Meter / Status Display (18) will show “FULL” if the recovery tank float valve has closed. If this indication occurs
and the tank is not full, see the Troubleshooting section.
Vacuum System Indicator (26):
• This indicator will be YELLOW if the vacuum/squeegee system is in the AUTO mode and the Drive Paddle (3) is in the neutral position. This indicates that
the vacuum system is enabled but the vacuum is currently off.
• This indicator will be GREEN if the vacuum is currently on. This indicates that the system is in the AUTO mode and the Drive Paddle (3) is not in neutral
or that the vacuum system is in the ON mode.
• This indicator will FLASH GREEN if the shutoff delay is keeping the vacuum on. This occurs if the vacuum system is in the AUTO mode and the Drive Paddle
(3) goes to the neutral position. This will also occur if the vacuum system is turned off while it was in either the AUTO or ON modes. The shutoff delay
will turn the vacuum off after the delay period.
• This indicator will be OFF if the vacuum/squeegee system is in the OFF mode.
Heavy Scrub Mode Indicator (28):
• This indicator will be YELLOW if the heavy scrub mode has been selected but the scrub motor is off. This will be the case if the Drive Paddle (3) is in the
neutral position. The scrub motor will stay on for approximately 3 seconds after the Drive Paddle (3) returns to the neutral position.
• This indicator will be GREEN if the heavy scrub mode has been selected and the scrub motor is on.
• This indicator will be OFF if the scrub mode is off or if the normal scrub mode has been selected.
Normal Scrub Mode Indicator (30):
• This indicator will be YELLOW if the normal scrub mode has been selected but the scrub motor is off. This will be the case if the Drive Paddle (3) is in the
neutral position. The scrub motor will stay on for approximately 3 seconds after the Drive Paddle (3) returns to the neutral position.
• This indicator will be GREEN if the normal scrub mode has been selected and the scrub motor is on.
• This indicator will be OFF if the scrub mode is off or if the heavy scrub mode has been selected.
Scrub Mode Off Indicator (32):
• This indicator will be RED if the scrub system is inhibited for any reason. Possible reasons are:
• The scrub deck has not returned to the UP position.
• A system fault
• Low voltage condition
• This indicator will be GREEN if the system is ready to be placed in either the normal or heavy scrub modes.
• This indicator will be OFF if either the normal or heavy scrub modes have been selected.
• This indicator will flash RED if there is a fault in one of the scrub system components. This will be accompanied by an error indication on the Hour Meter
/ Status Display (18).
Brush Remove Indicator (34):
• This indicator will be YELLOW when it is OK to activate the remove feature, otherwise it will be off.
• This indicator will be GREEN if the remove process is activated.
Brush Install Indicator (36):
• This indicator will be YELLOW when it is OK to activate the install feature, otherwise it will be off.
• This indicator will be GREEN if the install process is activated.
DESCRIPTION OF THE BATTERY CONDITION INDICATOR
Attention: See the Electrical System manual section for the explanation of the battery condition indicator lights.
DESCRIPTION OF THE HOURMETER/STATUS DISPLAY
The 5 character display in the middle of the control panel is primarily used as a display for the hourmeter function. This display is also used to display the following
information depending upon which mode the control is in:
• Error codes*
• Brush pressure adjustment setting for normal and heavy scrub modes
• Display of service test mode and control system default parameters*
• Recovery tank FULL indicator*
*NOTE: Reference (in the Electrical System) the Main Control Board Troubleshooting Guide and the Main Control Board Special Program Options sections. These
sections will explain the machine error code descriptions and scrub system controller default parameter changes.
DESCRIPTION OF INDICATORS ON THE CONTROL PANEL: (CONTINUED)
revised 12/02

14
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FORM NO. 56043057 ConvertaMAX
™
28/34, I
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MAX
™
28HD/34HD, BA 750/850
SOLUTION SYSTEM
FRONT
A
B
Fill Opening (Front)
Fill Opening (Rear)
(L1)
Electrical
Solenoid
Valve
Solution Tank
C
D
FUNCTIONAL OVERVIEW
The ConvertaMAX™28, I-MAX™28HD and BA 750/850 models have a solution tank fill capacity of 24-gallons (90 liters). The ConvertaMAX™34
and I-MAX™34HD models tank capacities are 30-gallons (114 liters). All models use two tank fill openings one located in the front and another
in the rear, which offers ease of filling. Plumbed into the main solution control valve hose outlet is a serviceable solution filter, to keep debris from
entering the solenoid valve. Also fitted to the tank is a flexible hose used to indicate the solution level and to drain the tank for system maintenance.
See Figure 1*. The solution system uses (2) valves to regulate the amount of solution dispensed onto the floor. The knob (A) located on the control
panel operates the main solution valve (B) that controls the needed flow volume demand to the scrub brushes. The (L1) electrical solenoid valve
stops and starts the solution flow to the scrub brushes. The electrical circuit that turns on (energizes) the solenoid coil is activated through the
(A3) control panel switch buttons and the (A2) main controller assembly. Note: See the Know Your Machine section in this manual for a complete
explanation of the solution operation modes.
During normal and heavy machine scrubbing the solution systems Auto Mode is selected and works in conjunction with the wheel drive speed
controller and the (A2) main controller’s scrub system outputs to turn On & Off the (L1) solenoid valve. The solution will flow to the scrub brushes
when the main flow control valve is open, the scrub deck is lowered and the handle drive paddle (box) is pushed or pulled into Fwd or Rev. Note:
When the solution On/Off button is turned Off, no flow can occur regardless of the manual flow control valve being On, drive control paddle activated
and the scrub deck down.
FIGURE 1
*Note: Figure 1 shows the solution components of the ConvertaMAX™28, I-MAX™28HD, BA 750 and BA 850 (old style). Similar components
are found on the ConvertaMAX™34 and I-MAX™34HD.
revised 12/02

FORM NO. 56043057 ConvertaMAX
™
28/34, I
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MAX
™
28HD/34HD, BA 750/850
-
15
SOLUTION SYSTEM
E
FRONT
F
FRONT
F
E
ConvertaMAX™28, I-MAX™28HD, BA 750 and BA 850 ConvertaMAX™34 and I-MAX™34HD
TROUBLESHOOTING GUIDE
Problem Possible Cause
Inadequate or no solution flow No solution in the tank
Main solution flow control valve knob is in the off position
Clogged solution filter, valves and hoses
Defective solution solenoid valve (L1)
Solution system fault in the main controller A2*
*Reference the Main Control Board Troubleshooting Guide in the Electrical System of this manual for further information.
SOLUTION SYSTEM MAINTENANCE
• Solution Tank: See Figure 1. Weekly empty the solution tank; remove the solution Drain Hose (C) from its storage area (located on the right
rear control handle compartment). Direct the hose to a designated “Disposal Site” and flush the tank with clean water.
• Solution Filter: Remove and clean the inline Solution Filter (D). To access the filter housing for removal, work underneath the middle left side
chassis panel. No tools are needed to remove the filter (hand tighten only). Service Tip: The manual solution control knob must be placed in the
full OFF position. This prevents loss of solution when servicing the filter strainer with a partial or full tank.
SOLENOID VALVE REMOVAL (BEFORE SN BREAK)**
1Drain the solution tank, or put the flow control valve knob in the full off position to prevent solution loss.
2Lower the brush deck to the floor with the scrub brushes installed. Don’t turn the key switch off until disconnecting the battery pack connector.
This procedure is done to prevent the scrub deck from automatically raising when the key is turned off.
3Remove the front brush head shroud (held in place by 6 screws) and the right side scrub brush skirt assembly from the machine.
4Disconnect the solenoid wire assembly pig tail connector. Unplug the solenoid valve wire assembly connection from the machine harness.
5Loosen the two hose clamps and separate both solution hoses at the solenoid valve body.
6See Figure 2. Remove the Insulated Bushing (E) from the valve body nipple, then remove the (F) Conduit Anchor Connector from the nipple
as shown.
7Pull the valve body to the rear and guide the coil wires through the slot in the mount bracket to complete removal. Make service repairs and
re-install in reverse order.
FIGURE 2
**Note: Follow these instructions for machines before these serial numbers. ConvertaMAX™28 – 1520376, I-MAX™28HD – 1516325, BA 750
– 1516328, BA 850 – 1516334, ConvertaMAX™34 – 1521967, I-MAX™34HD – 1517856.
revised 12/02

16
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FORM NO. 56043057 ConvertaMAX
™
28/34, I
-
MAX
™
28HD/34HD, BA 750/850
SOLUTION SYSTEM
SOLENOID VALVE DISASSEMBLY AND CLEANING (BEFORE SN BREAK)*
1Remove the solenoid valve. See the Solenoid Valve Removal section for instructions.
2See Figure 3. Remove the (2) (G) Screws and nuts and disassemble the valve (be careful not to lose any internal parts).
3Thoroughly wash dirt from block (H) and diaphragm (I).
4After reassembling, test the solenoid valve for proper operation.
Note: Solenoid valve replacement seal kit (Viton) part number 56324506.
SOLUTION FILTER REMOVAL (BEFORE SN BREAK)*
1Drain the solution tank using the solution drain hose or put the flow control valve knob in the full off position to prevent solution loss.
2See Figure 4A or 4B. Loosen the (2) Hose Clamps (J) and pry off both the solution hoses (inlet & outlet) from the filter head barb fittings.
3Loosen the (2) Hose Clamps (K) and separate the filter housing from the filter mounting bracket tabs.
SOLUTION FLOW CONTROL VALVE REMOVAL (BEFORE SN BREAK)*
1Drain the solution tank using the drain hose.
2See Figure 4A or 4B. Loosen the (2) Hose Clamps (L) & (M) and pry off both solution hoses (inlet & outlet) from the shut off valve.
3Remove the (2) Set Screws (N) from the adjustment rod connection Adapter (O).
4Remove the (2) Nuts (P) & Screws (Q) that secure the Valve Mount Bracket (R) then separate the valve from the rod connection and remove
the bracket and valve from the machine.
5With the valve and bracket removed loosen the Hose Clamp(s) (S) and remove the valve from the mount bracket.
*Note: Follow these instructions for machines before these serial numbers. ConvertaMAX™28 – 1520376, I-MAX™28HD – 1516325, BA 750 –
1516328, BA 850 – 1516334, ConvertaMAX™34 – 1521967, I-MAX™34HD – 1517856.
FIGURE 3
G
H
I
G
revised 12/02

FORM NO. 56043057 ConvertaMAX
™
28/34, I
-
MAX
™
28HD/34HD, BA 750/850
-
17
SOLUTION SYSTEM
FRONT
J
L
J
M
O
K
Q
N
P
R
L
K
J
J
Q
N
S
O
R
M
K
K
FRONT
S
S
FIGURE 4B ConvertaMAX™34 & I-MAX™34HD
FIGURE 4A ConvertaMAX™28, I-MAX™28HD, BA 750 & BA 850
revised 12/02

18
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FORM NO. 56043057 ConvertaMAX
™
28/34, I
-
MAX
™
28HD/34HD, BA 750/850
SOLUTION SYSTEM
SOLENOID VALVE REMOVAL (AFTER SN BREAK)**
1Drain the solution tank or put the Flow Control Valve Knob (A) (shown in Figure 1) in the full off position to prevent solution loss.
2Remove the lower left side chassis panel (held in place by 3 screws) and the left side scrub brush skirt assembly from the machine.
3See Figure 5. Unplug the L1 solenoid valve wire assembly connection from the machine harness.
4Loosen both the inlet and outlet Hose Clamps (T) and (U) that secure the hoses to the valve body.
5Separate (pry) the solution outlet hose off from its valve body barbed fitting.
6Remove the (2) Hex Screws (V) that secure the valve to the Mount Bracket (W), then pull the valve body to the front separating it from the
solution inlet Hose (X), completing the part removal.
SOLENOID VALVE DISASSEMBLY AND CLEANING (AFTER SN BREAK)**
1Remove the solenoid valve. See the Solenoid Valve Removal section for instructions.
2See Figure 5. Remove the (4) (Y) Screws and disassemble the valve (be careful not to lose any internal parts).
3Thoroughly wash dirt from block (Z) and diaphragm (AA).
4After reassembling, test the solenoid valve for proper operation.
FIGURE 5
FRONT
T
W
X
U
V
Assembly
AA
Z
Y
L1
SOLUTION FILTER REMOVAL (AFTER SN BREAK)**
1Drain the solution tank using the solution drain hose or put the flow control valve knob in the full off position to prevent solution loss.
2See Figure 6A or 6B. Loosen the (2) Hose Clamps (BB) and pry off the inlet solution hose from the filter head hose barb fitting.
3Remove the (2) Hose Clamps (CC) that secure the filter housing to the Mount Bracket (W), then pull the valve body to the rear separating
it from the solution outlet hose, completing the part removal.
**Note: Follow these instructions for machines with these serial numbers and after. ConvertaMAX™28 – 1520376, I-MAX™28HD – 1516325, BA
750 – 1516328, BA 850 – 1516334, ConvertaMAX™34 – 1521967, I-MAX™34HD – 1517856.
revised 12/02