2 45735677_ed1
Always wear eye protection when operating or performing maintenance on this tool.
Always turn o the air supply and disconnect the air supply hose before installing, removing or adjusting any accessory on this tool or
before performing any maintenance on this tool.
Note:When reading the instructions, refer to exploded diagrams in parts Information Manuals when applicable (see under Related Documentation
for form numbers).
Disassembly
General Instructions
Never apply excessive pressure by a holding device which may
cause distortion of a part.
Apply pressure evenly to parts, which have a press t.
Apply even pressure to the bearing race that will be press tted
to the mating part.
Use correct tools and xtures when servicing this tool.
Don’t damage“O” Rings when servicing this tool.
Use only genuine ARO replacement parts for this tool.
When ordering, specify part number, description, tool model
number and serial number.
Disassembly of Motor
Remove Sanding Pad (34).
Remove Lock Ring (27) and pull Motor and Seal (21) from
Housing.
Remove Retaining Ring (18).
Using special brass blocks to t around outside diameter
of Cylinder, clamp around Cylinder and press Shaft of
Counterbalance through Bearing (19) and End Plate (20).
Remove Blades (24), Rotor (23), and Key (28).
Remove End Plate (25) and Bearing (19).
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2.
3.
4.
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6.
7.
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3.
4.
5.
6.
Throttle Disassembly
Remove Vacuum Adapter (15) (if applicable) by pressing in on
tabs and pulling Vacuum Adapter out.
Remove Inlet Adapter (13), releasing Spring (12) and Valve (11).
Note: Do not remove seat (10) unless damage is evident.
Remove Muer (14).
To remove Valve Stem (6), remove Roll Pin (8) and Lever (7).
Regulator Disassembly
Remove Lever (7) by removing Roll Pin (8).
Remove Snap Ring (5) from Regulator (3).
Remove regulator assembly (3) - includes 2“O” Rings (4).
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2.
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4.
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3.
Assembly
Assembly of Motor
Grease and assemble “O”Ring (26) to Lock Ring (27).
Assemble Lock Ring over Counterbalance (29).
Assemble Bearing (19) into End Plate (25), pressing on outer race
of Bearing.
Assemble End Plate (25) onto Shaft of Counterbalance, pressing
on inner race of Bearing.
Install Key (28) in key slot.
Assemble Rotor (23) to Counterbalance, aligning key-way to Key (28)
.
Assemble Five rotor blades (24) to Rotor Slots.
Assemble Cylinder (21) over Rotor, aligning Roll Pin in Cylinder
with slot in End Plate.
Assemble Bearing (19) into End Plate (20), pressing on outer race
of Bearing.
Assemble End Plate (20), with Bearing (19), to Counterbalance,
pressing on inner race of Bearing.
Note: Align slot in End Plate with Roll Pin in Cylinder.
Install Retaining Ring (18) to groove in Counterbalance, with bow
in ring positioned as shown in parts illustration page.
Assemble Seal (22) to grooves in Cylinder.
Assemble Motor to Housing, aligning Seal (22) with air inlet.
Tighten Lock Ring (27), securing Motor Assembly.
Assemble Sanding Pad (34) and tighten securely.
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15.
Throttle Assembly
Coat Valve Stem (6) with ARO 29665 spindle oil and assemble into
Housing with hole in Valve Stem in line with Housing to accept
Valve (11).
Assemble Seat (10) into Housing with rounded corners into
housing rst.
Coat Valve (11) with ARO 29665 spindle oil and assemble into
housing, securing Valve Stem (6).
Assemble Spring (12) into Housing.
Assemble Inlet Adapter (13) to Housing, securing throttle
components.
Assemble Lever (7) to Housing, securing with Roll Pin (8).
Assemble Vacuum Adapter (15) or Plug (16) to Housing. To
assemble Vacuum Adapter, push into Housing until tabs on
Vacuum Adapter snap into slots in Housing. To assemble Plug,
push into Housing until it is ush with port opening.
Regulator Assembly
Assemble Regulator (3) and 2“O”Rings (4).
Insert Regulator assembly (3) into Housing (1).
Assemble Snap-Ring (5) into groove on regulator assembly (3).
Install Lever (7) by adding Roll Pin (8).
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5.
6.
7.
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4.
Related Documentation
For additional information refer to:
Random Orbital Sander Product Safety Information Manual 04580387.
Random Orbital Sander Product Information Manual 45735669.
Random Orbital Sander Parts Information Manual 04578407.
Manuals can be downloaded from www.irtools.com.
