Power Step Caterpillar 785D User manual

PSA-CAT785-FS 25-7-13B
Model No.: PSA-785D-FS
Serial No.: 785D-001 to 785D-002
Date Manufactured: Sept 2009
FOLDING RETRACTABLE STAIRWAY
Manual for Cat 785D Haul Truck

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Pg2
PSA-CAT785-FS 25-7-13B
CONTENTS
Page 2Section 1 Mounting and Installation
5Section 2 Electrical Installation
6Section 3 Installation of Hydraulic Power Pack Enclosure
7Section 4 Operating Procedure
8Section 5 Recommended Maintenance Procedure
9Section 6 Assembly Complete-Main Assemblies
10 6-1 Assembly Complete
Parts List
11 6-2 Landing Assembly
Parts List
13 6-3 Stair Assembly
Parts List
15 6-4 Electrical System
17 6-5 Hydraulic Cylinder
Valve diagram
19 6-6 Power Pack
21 Wiring Diagrams

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 1. Mounting and Installation
See Page 4
Pg3
PSA-CAT785-FS 25-7-13B
PROCEDURE
1. Remove OEM landing, so bottom of fixed stair and end of bumper look generally
as shown on View 2.
2. Assemble the Mounting Plate and various bolting pads as shown in View 4.
3. Locate the Mounting Plate and its attachments at the end of the bumper as shown
in Views 5 & 6. Note that the Seat Bars on the back of the mounting plate should
support the mounting plate on the truck's original landing mountings, at the
correct height.
4. Tack weld all relevant components to the truck bumper and wall plate. Try the
Power Step Landing and Stair in place against the mounting plate, without putting
any load on the mounting plate. If it fits correctly, remove the landing and unbolt the
mounting plate from the mountings. If it doesn't fit correctly make corrections to suit.
5. Weld the mounting components to the truck per View 3, including one additional
piece, 23 814 03 Gusset Bar. Where the top/bottom of the gusset bar and the web
plate of the Inner Mounting protrude above/below the wall plate to which they are
welded, neatly trim off the excess. Note that the little gussets are to be positioned
so as to approximately align with the diaphragm plates behind the wall plate - see
View 5.
6. Fit the Power Step Landing & Stairs. View 7 shows the location of all the relevant
boltholes.
Welding: all Cat SP to AS1554, 6 cfw uno.
NOTE
Follow all on-site/Mine lifting and safety procedures when installing
PSFS to Truck.

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Caterpillar 785D Haul Truck
Section 1. Mounting and Installation 23815
Pg4
PSA-CAT785-FS 25-7-13B

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 2. Electrical Installation
Pg5
PSA-CAT785-FS 25-7-13B
Remove centre console panel in cabin -
- to do this remove six (6) screws and gear selection knob.
Position stairway indicator panel on centre console, above hour meter.
- drill two mounting screw holes (6mm or 7/32")
- one electrical cable hole (12mm or 15/32")
- do not re-fix console Panel
Remove four (4) screws holding Caterpillar fuse panel behind operator's seat. Drill one
hole to insert Caterpillar fuse holder - fit fuse holder, into fuse indicator panel - tighten.
Drill size (12mm or 15/32").
Remove rear access panel from back of cabin and run short conduit through the main
cable gland to inside centre console, ensuring conduit goes underneath control box.
Connect blue wire start from conduit above to blue wire of cabin indicator panel harness.
In rear access, connect black wire, with 10mm eye terminal to machine ground, and blue
wire to outer terminal of newly inserted fuse holder.
Install short blue wire to screw terminal of Caterpillar circuit breaker, and other end to fuse
holder.
Run wiring harness from Power Step Folding Stairway magnetic proximity switch around
under radiator, and follow cabling/hose routing up to air line/ electrical outlet on rear Right
Hand Side of cabin.
Drill hole in RH Cabin access panel - route wiring harness in through access panel, and
through to under centre console - connect wires appropriately as colour coded. Hole
saw/drill size (24mm), cable tie harness as appropriate, approximately every 300mm.
WARNING
LOW OR FAULTY BATTERIES WILL VOID
WARRANTY ON THE POWER PACK AND ALL
ELECTRICAL SWITCHES AND COMPONENTS

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 3. Installation of Hydraulic Power Pack Enclosure
Pg6
PSA-CAT785-FS 25-7-13B
Main Hydraulic Enclosure is positioned on top of front bumper, as indicated position to
allow easy access as walking up or down diagonal stairway across front of radiator.
Mark mounting position.
Remove M10 x 25 bolts from bottom of enclosure to release mounting plates.
Remove paint from mounting area and mounting plate.
Stitch weld mounting plates in position.
Allow to cool, thoroughly and clean area, prime and paint.
Remount Enclosure, with ports to right hand side of truck.
Power Pack enclosure
mounting position

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 4. Operating Procedure
Pg7
PSA-CAT785-FS 25-7-13B
To Lower Stairway (from the machine)
Position machine in a level, safe area, away from the work face, whenever possible.
Apply park brake and lower engine speed to idle.
Check that the area below the Stair Access System is clear of people and
obstacles, and lower Stair by operating the two position electrical switch adjacent
to the stair, to the down position by pressing the switch down.
Hold the switch in the down position until Stair is fully lowered.
If the truck is parked on uneven ground, the bottom of the stairway may touch the
ground before the ladder is in the fully lowered position.
Should this occur, descend the Stair with caution.
To Raise Stairway
Ascend the Stair onto the landing of the truck.
Ensure the area around the Stair is clear of people and standing to the side, clear
of the area the handrails and Stair raises into, operate the electrical switch to the
raise position (up).
Hold the switch in the up position until the Stair is in the fully raised position.
The Stair is now raised and stored.
OPERATING NOTES
NOTE: FLOW CONTROL VALVE ADJUSTMENT:
The valve should be positioned to restrict the flow and speed of the Power Step when
lowering. Adjust the knob on top of the valve by turning left or right (clockwise) when the
step is being lowered, until it is lowering at a safe and reasonable speed.
When it is adjusted, lock the adjusting knob by tightening the grub screw located on the
side of the knob.
NOTE: MAGNETIC 'GO' SWITCH ADJUSTMENT:
The switch target trigger area is located on the opposite side and end from the cable entry
point on the switch. Once it is mounted to the switch bracket, adjust the switch in or out
from the stair steel trigger point, to be within 3mm - 10mm from touching each other when
the stair is in the desired rest position.
[DO NOT EXCEED 10mm DISTANCE BETWEEN THE SWITCH AND STRIKER PLATE].
Test by raising and lowering the Power Step a couple of times and adjust again if
necessary.

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 5. Recommended Maintenance Procedure
Daily Visually check stairway and structure for damage, loose components,
handrails, etc.
Check for hydraulic oil leaks from hydraulic cylinders, plumbing and hoses.
Notify the appropriate supervisor for any observed damage or malfunction.
500 Hours
Grease 2 grease nipples on Stair Pivot shaft
Check main mounting bolts for torque.
Check hydraulic oil level in power pack and top up as necessary. (Stairway in raised
position).
Top up using same hydraulic oil as used in hydraulics of machine.
Thoroughly check all electrical wiring for damage, replace as necessary.
Repeat daily check as above.
5000 Hours
Change hydraulic oil in tank of hydraulic power pack
It is recommended that the same hydraulic oil be used in the power pack as the
hydraulics of the machine.
Grease 2 grease nipples on Stair Pivot shaft
Check and inspect all main bolts on stairway system.
Retorque if required.
Repeat daily check as above.
Pg8
PSA-CAT785-FS 25-7-13B

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6. Assembly Complete - Main
Assemblies
See Pg 10
Pg9
PSA-CAT785-FS 25-7-13B
Item Part No. Part Name Qty
1
2
PSA-785D-FS
PS-23812-A
ASSEMBLYCOMPLETE
LANDING ASSEMBLY
(INC.HANDRAILS)
REFER TO 6.2FOR DETAILS
1
1
3PS-23811-A FOLDING STAIRS ASSEMBLY
(INC.HANDRAILS)
REFER TO 6.5 FOR DETAILS
1
4PS-62998-AH HYDRAULIC CYLINDER
REFER TO 6.5 FOR DETAILS 1
5PS-80103A-SLD POWER PACK
REFER TO 6.6 FOR DETAILS 1

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Hydraulic Operation
Section 6-1. Assembly Complete
Pg10
PSA-CAT785-FS 25-7-13B

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-2. Landing Assembly PS 23812-A
Pg11
PSA-CAT785-FS 25-7-13B

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-2. Landing Assembly PS-23812-A
Parts List
See Drawing Pg 11 (Does not include items 4,7,8,9,10 and 11)
Pg12
PSA-CAT785-FS 25-7-13B
Item Part No. Part Name Qty
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
PS-22502
PS-22507-97
PS-22507-96
PS-23813-00
PS-22502-01
PS-63009B
PS-23813-04
PS-23814-99
PS-23813-06
PS-23814-01
PS-23814-02
CPS-M16X50ZP
CPS-M12X50ZP
CPS-M12X40ZP
CPS-M12X35ZP
CPS-M12X30ZP
CPS-M12NZP
CPS-M16WH
CPS-M12WH
FRAME
HANDRAIL - FRONT
HANDRAIL - REAR
MOUNTING PLATE
CYLINDER MOUNTING
CYL-MOUNTING-BUSH - 1 1/4”OD x 1” x 28
FLOOR INFILL
INNER MOUNTING
LIFTING TAG
MIDDLE BOLT PAD
OUTER BOLT PAD
BOLT-M16 x 50
BOLT-M12 x 50
BOLT-M12 x 40
BOLT- M12 x 35
BOLT- M12 x 30
NUT-M12
WASHER - HARDENED - M16
WASHER - HARDENED - M12
1
1
1
1
1
1
1
1
1
1
1
12
6
4
12
5
12
6
27

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Caterpillar 785D Haul Truck
Section 6-3. Stair Assembly PS-23811-A
Pg13
PSA-CAT785-FS 25-7-13B

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-3. Stair Assembly PS-23811-A
Parts List
See Drawing Page 13
Pg14
PSA-CAT785-FS 25-7-13B
Item Part No. Part Name Qty
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
PS-23811
PS-23811-F
PS-23811-R
PS-22501
PS-22509
PS-40001
PS-63009-B
PS-22510
PS-23465
CPS-M12X120ZP
CPS-M12X30ZP
CPS-M12NZP
CPS-M12NN
CPS-M12WH
PS-61006-2
STRINGER ASSEMBLYONLY
HANDRAIL-FRONT
HANDRAIL-REAR
STAIR TREADS
PIVOT SHAFT-STAIRS
RUBBER STOP
CYL-MOUNTING BUSH
PIVOT BUSH
STAIR EXTENSION
BOLT-M12 x 120
BOLT-M12 x 30
NUT-M12
NYLOC NUT-M12
WASHER-HARDENED-M12
GREASE NIPPLE 1/4”BSP
1
1
1
6
1
1
1
2
1Set
2
36
36
2
40
2

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-4. Electrical System
PSA-CAT785-FS 25-7-13B Pg15
Cab Harness & Equipment
Refer Wiring Harness Drawing Page 18
3M Harness Ext. (Not shown) - PS-77011
PS-77002
Harness for Indicator Box PS-77003
Harness
PS-75430
Proximity Switch
PS-77004
Harness for
Proximity Switch
Proximity Switch Assembly
Mounted on Fixed Landing
Control Pendant Switch
Mounted on Handrail
PS-73013
Control Pendant Switch
PS-73013B
Pendant Bracket

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-5. Hydraulic Cylinder Assembly P/No. PS-62998-AH
Pg16
PSA-CAT785-FS 25-7-13B
Item Part No. Part Name Qty
1
1A
1B
1S
2
3
4
5
6
7
8
9
10
11
12
13
14
PS-62998-AH
PS-62998-HPK
PS-62998-A
PS-62998-P
PS-63103
PS-63201
PS-61154
PS-61151
PS-61157
PS-61158-5MM
PS61163
PS-61160
PS-61147
PS-61158-1MM
PS-61145
PS-60051-3.5
PS-60050-3.5
PS-61153
HYDRAULIC CYL. (with hard plumbing )
HARD PLUMBING KIT
HYDRAULIC CYLINDER 2 1/2”
PIN - CYLINDER (Incl. clips)
SEAL KIT (Not shown)
VALVE - PILOT OPERATED LOCKING
FITTING - ELBOW-9/16” JIC
FITTING - SWIVEL ELBOW 7/16”JIC
FITTING - O RING 1/4BSPPx 9/16”JIC
FITTING - 0.5mm RESTRICTION 90 DEG
REDUCER JIC x BSPP
TUBE (Cut to suit) 510mm
FERRULES
FITTING - 1MM RESTRICTION 90 DEG
FITTING- 9/6”JIC SWIVEL
HOSE- HYDR. ( 9/6”JIC SWIVEL FITTING)
HOSE- HYDR. ( 7/6”JIC SWIVEL FITTING)
FITTING - STRAIGHT 7/16”
1
1
1
2
1
1
1
1
1
1
2
1
2
1
1
2
1
1
CYL. END
ROD END
NOTE: HYDRAULIC CYLINDER ASSEMBLYP/No PS- 62998-AH includes Part No.s 1 to 11

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-5 Hydraulic Cylinder Assembly (Valve Diagram)
Pg17
PSA-CAT785-FS 25-7-13B
5mm 1mm
Double Acting Hydraulic System with
directional Control Valve and Cylinder
Lock Valve

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-6. Power Pack PS-80103A-SLD
See Parts List Pg 20
Pg18
PSA-CAT785-FS 25-7-13B
99A 8
4
13
27
26 6525
6
27
7A
10
29
11
16
14
12
330
24 3B
Hoses shown
dotted
View B View A
8A

NOTE.
THE RELIEF PRESSURE OF THE POWERPACK IS TO BE SET TO 2800PSI.
IF THE POWERPACK IS REPLACED,THIS RELIEF PRESSURE WILL NEED TO BE
RESET USING INLINE GAUGES.
FAILURE TO DO SO MAYRESULT IN ACCIDENT OR INJURY
FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-6 Power Pack PS-80103A-SLD
See Parts List Pg 20
Pg19
PSA-CAT785-FS 25-7-13B
15
22
21
View B
View A
32
33
24
14
19
11
16
30
23
9
9A
10
18
31
17
12
BEACON
WORKLIGHT

FOLDING STAIRWAY
Caterpillar 785D Haul Truck
Section 6-6 Power Pack PS-80103A-SLD
See Photos 18 & 19
Pg20
PSA-CAT785-FS 25-7-13B
Item Part No. Part Name Qty
1
2
3
3A
4
5
6
7
7A
8
8A
9
9A
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
PS-80103A-SLD
PS-21107-METAL
PS-80103A
PS-80103-CLAMP
PS-82415
PS-84214
PS-82492
PS-60051-900MM 9/16”
PS-60050-900MM 7/16”
PS-61152
PS-61150
PS-61177
PS-61176
PS-84213
PS-84212
PS-84303
PS-1712080
PS-73012
PS-82493
PS-HD10-5-16P
PS-41010
PS-41011
PS-41012
PS-41013
PS-41014
PS-41023
PS-41024
PS-41041
PS-41019
PS-41017
PS-41018
PS-41016
PS-73010
PS-73009
PS-HD10-3-16P
PS-HD10-5-16P
PS-41032
POWER PACK ASSEMBLY
MOTOR ENCLOSURE- SEALED ST/ST
POWER PACK
CLAMP ELECTRIC MOTOR
AUDIBLE ALARM
BRIDGE RECTIFIER
SOLENOID 24V START MOTOR
HYDR. HOSES 9/16”JIC STRAIGHT SWIVEL
HYDR. HOSES 7/16”JIC STRAIGHT SWIVEL
HYDRAULIC FITTING 9/16”
HYDRAULIC FITTING 7/16”
HYDRAULIC FITTING 9/16”
HYDRAULIC FITTING 7/16”
135A CIRCUIT BREAKER
5A CIRCUIT BREAKER
ISOLATION SWITCH
SEALED WIRING BOX
TOGGLE SWITCH KIT
BATTERYFEED STUDS
5 PIN SOCKET
DECAL-Battery Isolation
DECAL-Battery Supply C/B-135A
DECAL-Controller Supply C/B-10A
DECAL-Battery Supply-PosItive
DECAL-Battery Supply-Negative
DECAL-Up/Down
DECAL HYDRAULIC-HOSES
DECAL OIL TANK
DECAL BRIDGE RECTIFIER
DECAL SOLENOID
DECAL ALARM
DECAL RAISE/LOWER SWITCH
RUBBER BOOT RED
RUBBER BOOT BLACK
3 PIN SOCKET (PARK BREAK)
5 PIN SOCKET (AUTO-RAISE)
DECAL AUTO-RAISE SOCKET
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
6
3
1
1
1