ARO 8257-A User manual

Tool Products
OPERATOR’S MANUAL
INCLUDING:OPERATION,INSTALLATION& MAINTENANCE
PAR-A-MATIC® SELF-FEED TAPPERS
Models 8257-A( )-( ) AND 8357-A( )-2
SECTION Ml04
MANUAL 26
Released: 12/79
Revised: 10-6-95
Form: 1681-2
IMPORTANT: READ THIS MANUAL CAREFULLY BEFORE INSTALLING,
OPERATING OR SERVICING THIS EQUIPMENT.
FEATURES:
MODELS 8257-A( ) HAVE A BUILT-IN 4-WAY VALVE
MANUAL OR REMOTE OPERATION (MODELS 8257-A)
ADJUSTABLE STROKE LENGTHS
ADJUSTABLE FEED RATES
SPEED RANGES FROM 500 TO 1,450 R.P.M. AVAILABLE
1/4” MALE N.P.T.F. AIR INLET TO MOTOR
1/8” FEMALE N.P.T.F. REMOTE CONTROL PORTS
INDEX PAGE
MODEL IDENTIFICATION ................................................................. 2
GENERAL DESCRIPTION AND OPERATION ......................................... 2 and 3
SET-UP PROCEDURE ............................................................. 4 and 5
AIR AND LUBE REQUIREMENTS ......................................................... 6
MAINTENANCE ......................................................................... 6
RECOMMENDED AIR INLET SYSTEM ..................................................... 7
REMOTE CONTROL START AND RETRACT ......................................... 8 and 9
DISASSEMBLY AND REASSEMBLY ............................................. 10 thru 16
ACCESSORIES ................................................................ 16 thru 18
SERVICE KITS ......................................................................... 18
TROUBLE SHOOTING .................................................................. 19
DIMENSIONAL DATA ................................................................... 20
For parts and service information, contact your local ARO distributor, or the Customer Service Dept. of the Ingersoll-Rand Dis-
tribution Center, White House, TN at PH: [phone], FAX: [phone].
ARO Tool Products
Ingersoll-Rand Company
1725 U.S. No. 1 North l P.O. Box 8000 l Southern Pines, NC 28388-8000
1995 THE ARO CORPORATION l PRINTED IN U.S.A.
PROFESSIONALTOOLS

MODEL IDENTIFICATION
MODEL NUMBER R.P.M. AUXILIARY DRIVE MOTOR TOTAL
CANCELLED
8257-A5-( )
GEARING GEARING ASSEMBLY REDUCTION
8357-A5-2 500 33837
33999-1 37959-1 30.9:1
8257-A8-( ) 8357-A8-2 850 33837
34001-1 37959-1 18.9:1
8257-A14-( ) 8357-A14-2 450
33853 34001-1
37959-1 11.6:1
MODELS WITH -EU SUFFIX ARE “EC” COMPLIANT MODELS.
GENERAL DESCRIPTION AND OPERATION
Safe and efficient operation of your ARO Self-feed tool can best be attained by observing proper operating and maintenance proce-
dures. Keep hands and clothing away from rotating end oftool and all other moving parts. Eye protection should beworn atall times while
operating power tools. Disconnect air supply line to tool or shut off air supply line to tool and exhaust (drain) air line of compressed air
BEFORE removing or installing a tap or other such device or otherwise performing service or maintenance to the tool.
REMOTE CONTROL
REMOTE CONTROL RETRACT PORT
RETRACT BUTTON BLEED VALVE
MODEL8257-A( )
(SHOWN WITH COVER
REMOVED FOR CLARITY)
.EED VALVE
PAGE 2 OF 20

GENERAL DESCRIPTION AND OPERATION
M104
26
The Models 8257-A Tappers have built-in valving and are forward and retact stroke. Positioning of the spool valve is ac-
designed to automatically feed to a pre-set depth, trip and complished by actuating the “F” or “R” Button BleedValves,
return. located at the rear of the head.
The Models 8357-A Tappers are “thru-head” type and are
designedto operate in the forward and retract strokeswith the
useof external valving.
The following is a brief description of the various sectionsand
their function.
GEARING: The gearing for thesemodels is available in dou-
ble reduction planetary gearing assembly to provide three (3)
final spindle speeds.
The BUTTON BLEED VALVES exhaust air from the endsof
the spool valve, causing it to shift to the forward and retract
positions. Depressing the Button Bleed Valve marked “F”
shifts the spool valve to the forward feed position. When the --
drill reachesthe pre-set depth, the Stroke Adjustment Screw
will depressthe Button Bleed Valve marked “R”, this shifts
the spool valve to the retract position and retracts the piston
completing the cycle.
AIR MOTOR: The vane type air motor develops a minimum
of .4 horsepower. The motor will start within the first l/4 inch
of stroke and remain running thru the forward and retract
stroke, automatically shutting off upon completion of the cy-
cle.
The needletype FEED CONTROL VALVES regulate the flow
of air from the piston thus regulating the forward and retract
rate of feed of the piston. The Feed Control Valve marked
“F” regulatesthe forward feedrate of the piston and the Feed
Control Valve marked “R” regulates the retract feed rate of
the piston.
AIR PISTON: The air piston is of the double acting type, pro-
viding the forward and retract stroke movement. The piston
has an area of 2.0 square inches and develops approximately
170pounds of thrust with 90 p.s.i.g. at the piston inlet.
VALVE SECTION - Models 8357-A( ) : The valve sec-
tion housesthe needletype FEED CONTROL VALVE mark-
ed “SLOW FEED” located at top of the valve housing and
regulates the forward feed rate of the piston.
VALVE SECTION - Models 8257-A( ): The valve section
housesthe SPOOL VALVE, BUTTON BLEED VALVES and
the FEED CONTROL VALVES. The SPOOL VALVE is a
4-way bleed type valve used to port air to the piston for the
TOOL RETRACTED SIGNAL PORT - this port is located
in rear end of Piston Rod. The port is pressurized when the
motor starts and remains pressurized during the drilling cycle
until the motor shuts off when the unit is fully retracted.
.
MANUAL OPERATION OF MODELS 8257-A( )
The Models 8257-A( ) are shipped from factory with the Housing.
MANUAL BLEED VALVE (24130)installed in the “F” port
at the rear of the Valve Housing. If the unit is to be operated Each time the BUTTON BLEED VALVE marked “F” is
manually; loosen the two (2) Screws(Y154-19)securing Cover depressedthe unit will start in the advancing (forward) mode.
(40313-)to the Valve Housing and removethe Cover. Remove The unit will continue to advance until the BUTTON BLEED
the Button Bleed Valve from the “F” port at the rear of the VALVE marked “R” hasbeendepressedsufficiently to retract
Valve Housing and remove the Pipe Plug (Y227-2-L) fromthe the unit. SeeSET-UP PROCEDURE, PAGE 4. Should an
“F” port at the top of the Valve Housing. Install the Button EMERGENCY RETRACT be desired, install an additional
Bleed Valve (24130)in the “F” port at the top of the Valve Button BleedValve in the “R” port at the top Valve Housing.
Housing and seal off the “F” port at the rear of the Valve The EmergencyButton Bleed Valve can beusedto immediate-
Housing using the Pipe Plug(Y227-2-L). Replace the Cover ly retract the unit in the event of a misaligned part or similar
(40313-)and tighten Screws(Y154-19)securing Cover to Valve situation.
REMOTE CONTROL OPERATION MODELS 8257-A( )
The Models 8257-A( ) can beusedasa single unit application REMOTE RETRACT is accomplished by use of a Pressure
or in a multiple unit application. REMOTE START is ac- BleedValve (part no. 9600)installed in the “R” port located at
complished by useof aPressureBleedValve (part no. 9600)in- the top of the Valve Housing. The valve is then connected to a
stalled in either the “F” port at the rear of the Valve Housing remote MANUALLY operated valve in the same manner as
or the “F” port in the top of the Valve Housing. This pressure the Remote Start circuit. This valve is used as an emergency
bleed valve is then connected, by meansof l/8” I.D. tubing, retract in the event of a part misalignment or similar situation
to a remote operated valve which, when actuated, feeds air only as the unit, when properly set-up and applied, will
pressure to the Pressure Bleed Valve (9600). The Pressure automatically retract and return to the start position after
Bleed Valve then opens, bleeding air from “F” port of Valve reaching a pre-setdepth or stroke. SeeSet-Up Procedure page
Housing, causing Spool Valve to shift to the Forward Feed 4 and illustration on page8.
position thus starting the advancing (forward) mode of the
unit.
REMOTE CONTROL OPERATION MODELS 8357-A( ) 1
The Models 8357-A( )can beusedasa single unit application REMOTE RETRACT is accomplished by connecting, by use
or in a multiple unit application. REMOTE START is ac- of proper fittings and l/8” I.D. tubing, the “R” port at either
complished by connecting, by useof proper fittings and l/8” the top or at the rear of the Valve Housing to the same4-way
I.D. tubing, the “F” port at either the top or rear of the Valve valve the Remote Start circuit is connected. The 4-way valve is
Housing to a 4-way type valve which, when actuated, feedsair actuated once for the forward mode and actuated a second
pressureto the unit starting the advancing (forward) mode of time to retract the unit. The valve can be actuated at any time
the unit. after the unit has started the advancing (forward) mode to
retract the unit in the event of a part misalignment or similar
situation. Seeillustration on page9.
SPECIAL NOTE: The air inlet and remote ports of this tool have tapered pipe threads and should not require thread sealants,such
assealant tapesor pipe joint compound. Thread sealants used improperly can causevalve or tool malfunction.
FORM1661-2 PAGE3 OF20

MOUNTING
The nose end of the Outer Sleeve is provided with 2”-16 with the foot and flange type brackets. Foot and flange type
L.H. threads (remove thread guard for use)and a 2” x l-1/8” mounting brackets are available for tool mounting - seeAc-
long pilot diameter for fixture mounting. A groove is also pro- cessoriesSection. The tool can be mounted in any position
vided in the Outer Sleevefor a retaining ring which is supplied desired without impairing the function of the tool.
SET-UP PROCEDURE
NOTE: For set-up purposes; loosen the two (2) Screws
(Y154-19)securing Cover (40313-) to the Valve Housing and
remove Cover (40313-).After the set-up has been completed,
replace the cover and tighten the two (2) Screws (Yl54-19)
securing Cover to Valve Housing. CAUTION: Adjust with
care. Keepfingers clear from betweenAdjustment Screwsand
Valves or Housing. Keep clear of rotating end of unit with
hands and/or clothing.
A minimum distance of l/4 inch must be maintained between
the work piece and the tap point with the tapping unit in its
fully retracted position when setting-up the unit for operation.
This will allow the Air Motor to start and reach free speed
before the tap point touches the work piece.
STROKE ADJUSTMENT: Determine the Total Stroke
Length the tap must travel to perform thetapping operation
(seefigure below). Adjust the length of the stroke by rotating
the Stroke Adjustment Screw “A” sothe distance betweenthe
leading edgeof the screwand the Stud equalsthe Total Stroke
Length. SecureScrew with Jam Nut.
MODELS 8257-A( ) ONLY - After adjusting Adjustment
Screw“A” to equal the total stroke length, rotate Adjustment
Screw “B” so the distance between the leading edge of the
screw and the Button Bleed Valve (24130) is slightly greater
than the Total Stroke Length. Start the unit and let the unit
advance until Adjustment Screw “A” contacts Stud then
rotate Adjustment Screw “B” until screw depressesButton
TOTAL STROKELENGTH
Bleed Valve (24130)sufficiently to retract the unit.
FEED RATE CONTROL VALVES, MODELS 8257-A: The
retract Feed Rate Control Valve marked “R”. located at the
top of the Valve Housing, regulates the rate of return of the
piston. Open this Valve approximately 1-112turns (counter-
clockwise) from the closed position for setting-up of unit.
Close the FeedRate Control Valve marked “F” by turning it
in (clockwise).
Start the unit by depressing the Button Bleed Valve (24130)
marked “F” then, slowly turn the Valve counter-clockwise
opening the Valve until the desired rate of forward feed is at-
tained.
A final adjustment of the rate of return (retraction) can be
made with the FeedRate Control Valve marked “R”.
FEED RATE CONTROL VALVE, MODELS 8357-A: The
FeedRateControl Valve marked “slow feed” at the top of the
Valve Housing regulates the forward rate of feed. Open this
Valve approximately two (2) full turns (counter-clockwise)
from the closedposition for setting-up purposes. Start the unit
in the forward mode and rotate slow-feed valve until desired
rate of feed is attained.
SeeSet-Up Instructions for optional Hydraulic Check unit for
controlling thrust during tapping.
ADJUSTMENTSCREW“B”T
THIS DISTANCEMUST E
PENETRATION TOTAL STROKELENGTH
PAGE4 OF20

SET-UP PROCEDURE FOR OPTIONAL HYDRAULIC CHECK
M104
26
The Hydraulic Check unit is an accessoryitem used with the
Models 8257-A( ) and 8357-A( ) when controlled thrust is
MOUNTING INSTRUCTIONS
required. The Hydraulic Check is a sealedunit with a low fric-
tion diaphragm. The hydraulic fluid need not be replenished. Assemble Mounting Bracket (40316) with Hydraulic Check
The Hydraulic Check is available in 1 and 2 inch stroke (38922-)to the Valve Housing with two (2) Screws(Y157-44)
lengths. and Washers(30997).
SET-UP INSTRUCTIONS TO CONTROL RATE OF FEED: --
1. Measure distance from tap Point to Work Piece
(DISTANCE “Y”).
2. DISTANCE “X” betweenthe Hydraulic Check (38922)
and the Trip Bracket (41713-) must be less than
DISTANCE “Y” to prevent damageto the tap Point
when it approaches the Work Piece. This can be ad-
justed by loosening the Screws(Yl57-44) in the Moun-
ting Bracket (40316)and sliding the Hydraulic Check to
the desiredposition. Retighten Screws(Y157-44)before
operating unit.
3. Increase the air flow thru the Feed Control Valve by
opening two (2) turns from closed. This will allow the
FEEDRATE ADJUSTMENT-
4.
5.
6.
tap to advance rapidly until the Trip Bracket con-
tacts plunger of the Hydraulic Check.
TheHydraulicFeedRateAdjustmentis locatedatthe name
plate end of the Hydraulic Check.Rotateextended spindle
until the slot on spindle is located midway between the
highest and the lowest settings.
Start Tool and the tap will advanceat a rapid rate, un-
til the Trip Bracket contacts the plunger of the
Hydraulic Check.
Slowly rotatethe HydraulicFeedRatecounterclockwisefor
faster feed rate or clockwise for slower feed rate.
ADJUSTMENTSCREW“B”
PARTS INDICATED BY ASTERISK (*) ARE INCLUDED
lN 40591-( ) HYDRAULIC CHECK ASSEMBLY.
SEE PAGE 18 FOR HYDRAULIC CHECK
DIMENSIONAL DATA.
FORM1681-2
PAGE 5 OF 20

AIR AND LUBE REQUIREMENTS
AIR PRESSURE of 90p.s.i.g. (6 bar) at air inlet of the tool is
required for maximum motor efficiency. An air regulator
should be installed to maintain this pressure when tool is in
operation.
approximately every 160hours of operation. Tapper assembly
should contain approximately 1/2 oz. (14.1 g) grease.
FILTERED AND OILED AIR will allow the tool to operate
more efficiently and yield a longer life to operating parts and
mechanisms. A line filter capable of filtering particles larger
than 50 microns should be used with a line oiler.
Filter-Regulator-Lubricator (F.R.L.) assembly model
C28221-810 is recommended for use with this air tool. The ca-
pacity of the individual Filter-Lubricator is adequate to provide
clean (40 micron) oiled and regulated air for the tool. See recom-
mended air inlet system, page 7.
MOTOR is lubricated thru air inlet of unit by use of a
lubricator installed in air line. Spindle Oil 29665, 1qt. (.9 liter)
container or equivalent type 1light spindle oil is recommended
for motor lubrication. Consult manufacturer of air line
lubricator being usedto insure oil is compatible with construc-
tion of lubricator bowl.
BEARINGS, GEARS, ETC: grease33153, 5 lb. (2.3 kg) can,
or equivalent grade.
RECOMMENDED LUBRICATION: Gearing should be
greaselubricated every 160hours of operation. Inject grease,
(33153)or equivalent, 1to 2 strokesthru greasefitting in gear
housing. NOTE: Spindle must be extended from outer sleeve
sufficiently to exposegreasefitting in gear housing.
“O” Rings: Lubricant 36460.4 OZ. (113g) tube for lubrication
and installation of “O” Rings.
CAUTION: An excessiveamount of lubricant in a tool will af-
fect the speedand power. Each setof planetary gearing should
contain approximately l/8 oz. (3.5 g) of grease.
TAPPER ATTACHMENT: inject grease 33153, or
equivalent, thru pressurerelief hole in lower part of housing RECOMMENDED HOSE SIZE - 5/6” (8 mm) nominal in-
side diameter.
S. AT 100oF. OIL IS COMPATIBLE
AND GEAR GREASE,
SITY OF APPROX. 750
MAINTENANCE
DISCONNECT AIR SUPPLY from tool or shut off air supply
line to tool and exhaust (drain) air line to tool of compressed
air BEFORE performing serviceor maintenance to tool.
AIR TOOLS aremadeof precision parts and should behandl-
ed with reasonablecarewhen servicing. Excessivepressureex-
erted by a holding devicemay causedistortion of a part. Apply
pressure evenly when disassembling (or assembling) parts
which have a pressfit. When removing or installing bearings,
apply pressureto the bearing race that will be the pressfit to
the mating part; if this is not practiced, Brinelling of the bear-
ing racesmay occur making replacement necessary.It is im-
portant that the correct tools and fixtures are usedwhen ser-
vicing this Air Tool.
Double sealedor shielded bearings should never be placed in
solvent unless a good method of re-lubricating the bearing is
available. Open bearings may be washed but should not be
allowed to spin while being blown dry. When REPLACE-
MENT PARTS are necessary,consult drawing containing the
part for identification.
BEFORE REASSEMBLING, lubricate parts where required.
Use33153Grease,or equivalent, in bearings. Use36460Lubri-
cant for “O” Ring Assembly. When assembling “O” rings,
caremust beexercisedto prevent damageto the rubber sealing
surfaces.A small amount of greasewill usually hold steelballs
and other small parts in place while assembling.
DISASSEMBLY should bedone on aclean work bench with a
clean cloth spread to prevent the loss of small parts. After
disassemblyiscompleted; all parts should bethoroughly wash-
edin acleansolvent, blown dry with air and inspectedfor wear
levels, abuseand contamination.
WHEN ORDERING PARTS, be sure to list PART
NUMBER, PART NAME. MODEL NUMBER AND
SERlAL NUMBER OF TOOL. USE ONLY GENUINE ARO
REPLACEMENT PARTS.
For additional Maintenance information, the manual “Tips on Air Tools”, Form 5948 (English) or Form 2158-2X (Spanish) are available at
$5.00 each. Send request to: The ARO Corporation, One Aro Center, Bryan, Ohio 43506, Attn: “Sales Training”.
PAGE6 OF20

RECOMMENDED POWER AIR INLET SYSTEM Ml04
26
SUPPLY
Your ARO Self-Feed tool isdesigned to deliver specific horsepower and thrust to achieve high rates of work. To assure the unit will develop this power, care must be taken
IMPORTANT - the tool is power rated when 90 P.S.I. is present AT THE TOOL DURING OPERATION.
that the power air inlet system is correctly sized to permit the proper rate of air flow. Shown above is a system for a single tool that will supply correct delivery,
Shown below is the same system in schematic form.
SEE SPECIAL NOTE - PAGE 3 F = FILTER
R = REGULATOR
L = LUBRICATOR
F-R-L- MODEL C28221-810
If two or three units are to be installed. each unit should be supplied with a system like that shown below or use system like that above for each tool,
A-
114” CAP.
LUBRICATOR MODEL L26221-110
FILTER MODEL F25231-110FILTER MODEL F25231-110
REGULATOR MODEL R27231-100
REGULATOR MODEL R27231-100
114” CAP.
FORM 1681-2
LUBRICATOR MODEL L26221-110
PAGE 7 OF 20

BASIC REMOTE CONTROL FOR START
AND EMERGENCY RETRACT FUNCTIONS
MODEL 8257-A-( )
ARO INSTANT
TUBING - 100 FT. ROLLS
ModeI No.
59690-004
59690-104
59690-204
59690-304
59690-404
59690-504
59690-604
59690-704
Size
5/32
5/32
5/32
5/32
5/32
5/32
5/32
5/32
*packaged 10 to a box
REMOTE OPERATION
Remote operation of the unit may be achieved by connecting a 3-way valve to the remote start and/or remote retract ports, as shown above
TO START - depress the remote button momentarily. The unit will advance the drill to a preset depth and automatically retract to the initial position whereupon the
unit will stop.
EMERGENCY RETRACT-depress the emergency button momentarily. This signal to the unit will shift the built-in pressure operated valve. commanding the unit to
retract immediately to the initial position whereupon the unit will stop.
NOTE: MANUAL START and EMERGENCY RETRACT buttons on the tool are fully operational even when remote control is used. The manually operated buttons
can be used when set-up is required.
Shown below is the same system in schematic form
SEE SPEClAL NOTE - PAGE 3
SUPPLY
SUPPLY
PAGE 8 OF 20

BASIC REMOTE CONTROL FOR START
AND EMERGENCY RETRACT FUNCTIONS
MODEL 8357-A-( )
M104
26
ARO INSTANT
TUBING - 100 FT. ROLLS
Model No. Color Size
59690-004 White 5/32
59690-104 Black 5/32
59690-204 Green 5/32
59690-304 Red 5/32
59690-404 Blue 5/32
59690-504 Yellow 5/32
59690-604 Gray 5/32
59690-704 Orange 5/32
*packaged 10 to a box.
REMOTE OPERATION
Remote operation IS achieved by connecting a 4-way valve to the remote start and retract ports as shown above. This valve supplies power directly to the feed piston
in the tool.
TO START - move lever forward. The unit will advance to a pre-set depth adjustment screw contacts stud on valve housing).
TO RETRACT - move lever rearward (back). The unit will retract to the initial position.
EMERGENCY RETRACT - the unit will retract at any time the lever is moved to the rearward (back) position. The motor runs continuously as long as air pressure is
present at the air inlet to the tool. A shut-off valve should be installed in the air inlet line to completely shut the tool off in case of an emergency.
Shown below is the same system in schematic form.
SEE SPECIAL NOTE - PAGE 3
FORM 1881-2 PAGE 9 OF 20

DISASSEMBLY AND REASSEMBLY OF TOOLS
DISCONNECT AIR SUPPLY from tool or shut off air supply
and exhaust (drain) line of compressedair BEFORE perform-
ing maintenance or service to tool.
To minimize the possibility of parts damageand for conven-
ience, the steps for disassembly or reassembly listed on the
following pagesare recommended.
Listed herearethe three basicsectionsof the tool and instruc-
tions for removing them from tool. To further disassemble,
refer to the appropriate section outlined in the following
pages.
Securetool in a suitable holding device clamping on the Valve
Housing. CAUTION: DO NOT CLAMP on the OUTER
SLEEVE of the Piston and Motor Section as it may cause
distortion of the piston Air Cylinder (38866) impairing the
function of the tool.
TAPPER SECTION
Using suitable wrenches on flats of Ring Gear and Tapper
Housing, unthread and remove Tapper Assembly from tool -
R.H. threads. Seepage11for complete disassemblyof Tapper
Assembly.
GEARING SECTION
Remove Tapper Assembly as outlined above. Thread Adjust-
ment Screws(40292-2)a]] the way back and push Piston Rod
all the way forward exposing flats of Motor Housing out of the
Outer Sleeve. Using wrenches on flats of gear housing and
motor housing, unthread and remove Gearing Section from
motor housing - R.H. threads. If tool has both Drive and
Auxiliary Gearing, remove Drive Gearing from Auxiliary
Gearing using wrencheson flats of eachgear housing - R.H.
threads. Seepage 12for complete disassemblyof gearing.
MOTOR AND PISTON SECTION
RemoveGearing from tool asoutlined in the Gearing Section.
The Motor Assembly along with Spacer(32310)can beremov-
ed from Motor Housing after the removal of the Gearing Sec-
tion. Seepage13for complete Motor disassembly.To remove
PISTON SECTION; removeCover (40313-),Adapter (44883),
Washer (Y14-616) and Trip Bracket (41713) from end of
Piston Rod. Place Valve Housing in a suitable holding device
with Outer Sleevein an upright position. Using a strap type
wrench on Outer Sleeve unthread and remove Outer Sleeve
from Valve Housing - LEFT HAND THREADS. NOTE:
Motor Housing, Piston Rod, Piston and components will re-
main inside Outer Sleevewhen Outer Sleeveis removed from
Valve Housing. CAUTION: Remove Outer Sleevewith care,
Pull Outer Sleevestraight up and away from Valve Housing so
asnot to bend the Air Cylinder (38866), damaging the inside
diameter. The Air Cylinder may remain attached to the Valve
Housing when Outer Sleeveis removed. If this is the case,pull
the Air Cylinder straight off the Valve Housing exercising cau-
tion so as not to damagethe inside diameter of Cylinder. If
Cylinder remains inside Outer Sleeve refer to page14 for
removal procedure. VALVE SECTION
The Spool Valve, Feed Control Valves and Button Bleed
Valves can be serviced without removing the Valve Housing
from the tool. If the “O” Rings (Y325-15)contained inside the
Valve Housing should need to be replaced follow the
disassemblyprocedure for the removal of the Piston Section.
The Gearing Section neednot beremoved from tool to remove
only the Valve Section. Seepage 15 for disassemblyof Valve
Section.
r
PIPE PLUG Y227-2-L
TRIP BRACKET
ADJUSTMENT SCREW 40292-2
ADAPTER 44883
WASHER Y14-616
PIPE NIPPLE 40857-6-
COVER 403 13
MUFFLER
VALVE HOUSING
ASSEMBLY
MANIFOLD
(SEE PAGE 1
MOTOR ASSEMBLY
TORQUE PIN 40312-l
SPACER 32305
AUXILIARY GEARING
DRIVE GEARING
VALVE
SECT ‘ION
ANDMOTOR
PISTON
SECTION
GEARING
SECTION
PAGE10 OF 20

TAPPER SECTION
M104
26
TAPPER ATTACHMENT ASS’Y 34000-1
I
NOT INCLUDED WITH TAPPER ASS”Y
RETAINING RING Y145-2 PIN Y122-105
RETAINER 33552
GEAR HUB (2) 31412
DISASSEMBLY REASSEMBLY
Drive out Pin (Y122-105) and remove Chuck from Spindle.
Place housing in a suitable holding device and using a wrench
on flats of Retainer (33552) unthread and remove Retainer
from spindle. Remove Spring (36355), Washer (F15-10) and
Retaining Ring (Y145-2) from spindle. Spindle and Jaw
Assembly (33554)can now beremovedout thru large open end
of housing.
To remove Clutch Jaw (35209),push Pin (31419)out thru jaw
and spindle - Pin (31419)is held in place by Spring (30852)
and may drop out when Pin is removed. After removal of Pin,
Jaw can be removed from spindle.
To remove Bevel Gear (39555), remove Hubs (31412) and
Gears (39554).
Assemble Spring (30852)into small hole provided in Spindle
and assembleClutch Jaw (35209)to spindle aligning hole thru
jaw with hole thru spindle and securewith Pin (31419).It may
be necessaryto reach thru hole from opposite side using a
small screwdriver to depress Spring (30852) to allow Pin
(31419)to be inserted thru hole.
AssembleGear (39555)and Jaw (35210)to Spindle and assem-
ble spindle to housing. Assemble Retaining Ring (Y145-2),
Washer (F15-l0), Spring (36555) to spindle and secure with
Retainer (33552). Assemble Gears (39554) to housing and
secure with Hubs (31412). Assemble Chuck to spindle and
secure with Pin (Y122-105). Assemble Spacer (31420) into
housing and assembleTapper Assemble to tool and tighten
securely.
--
FORM 1661-2 PAGE 11OF 20

GEARING SECTION
DISASSEMBLY
DRIVE GEARING
REASSEMBLY
RemoveGearing from tool asoutlined on page 10.Place Ring
Gear in a suitable holding deviceand using a suitable punch or Pack Bearings and lubricate Gears and Shafts liberally with
pin tap drive end of Spindle to loosen from Ring Gear. Further grease (33153), or equivalent, during assembly. Gearing
disassemblyshould be done only if it is necessryto replace a assembly should contain approximately l/8 oz. (3.5 g) of
grease.
part, as brinelling of the bearing races may occur making
replacement necessary.
Remove Bearing (Y65-13). Spacerand Shafts from Spindle to
remove Gears. Using a suitable punch or similar tool, alter-
nately tap end of Shafts to remove Bearing (32325)from Spin-
dle.
Using a suitable tool, lightly tap Jaw (35210)to remove Bevel
Gear (39555). Jaw (35210) and Bearing (31068) from Ring
Gear. Bearing is light pressfit on Bevel Gear. Jaw is light press
fit in Bevel Gear.
AssembleSpacerand Bearing (Y65-13) to drive endof Spindle.
AssembleGearsto Spindle and securewith Shafts. Align notch
in endsof Shafts with Spacer.AssembleSpacer(37676).where
applicable, and Bearing (32325)to Spindle.
Assemble Jaw (35210) and Bearing (31068) to Bevel Gear
(39555)and assembleto Ring Gear. Assemble Key (31409)to
Spindle and assembleSpindle and components to Ring Gear.
SPLINE GEAR 30901
BEARING 32325
-BEVEL GEAR 39
SPINDLE 33424
OT INCLUDED IN GEARING ASS’Y.
AUXILIARY GEARING
Disassembly and Reassembly of the Auxiliary Gearing is
similar to that of the Drive Gearing. Gearing should only be
disassembled if it is necessary to replace a part as brinelling of
the bearing races may occur ‘making replacement necessary.
Remove Bearing (32325)and Spacerfrom drive end of Spin-
dle. Then, remove other Bearing and Gears from Spindle as
outlined for Drive Gearing. Pack bearings and lubricate gears
liberally upon assembly as per Drive Gearing.
Y147-7 RETAINING RING 30901 DRIVE GEAR
(9NT-17 EXT. TEETH 37676 SPACER
32325 BEARING
33853 GEARING ASS’Y
3.4:1
Y147-7 RETAINING RING
32326 ADAPTER
32312 SPACER 32325 BEARING
33425 SPINDLE
PAGE12 OF 20

MOTOR AND PISTON SECTION
AIR MOTOR
M104
26
DISASSEMBLY
Remove Motor Assembly from tool as outlined on page l0.
Grasp Cylinder in one hand and tap splined end of Rotor with
a non-metallic hammer; motor will come apart. Remove Cap
(38783) and Shield (38805) to remove Bearing (Y65-7) from
End Plate.
REASSEMBLY
Assemble Bearings into End Plates and assembleEnd Plate
(37956) to Rotor. When assembling bearing to rotor insure
pressureis applied squarely to the inside raceof bearing. Coat
I.D. of Cylinder with Spindle Oil and assembleCylinder over
Rotor aligning air inlets and Roll Pin of Cylinder with air inlet
and hole in End Plate for Roll Pin. Assemble Blades to Rotor
and assembleEnd Plate (31158).with bearing, to Rotor align:’
ing Roll Pin and hole in End Plate. Apply pressureto inside
bearing race when assembling to Rotor. Assemble Shield
(38805)and Cap (38783)to End Plate (37956). Insure motor
doesnot bind (if rotor binds, tap splined end lightly to loosen)
and assembleMotor with Spacer (32310) to Motor Housing
and assemblegearing to tool.
P
‘ARTS MARKED THUS MARE INCLUDED IN SERVICE KIT NO 41325, SEE PAGE 18.
REARING Y65-15
END PLATE 31158
r
CYLlNDER 3795
L
MOTOR ASSEMBLY 37959-l
FORM 1681-2 PAGE 13 OF 20

DISASSEMBLY
AIR PISTON
Remove Motor and Piston Section from tool as outlined on
page 10. If the Air Cylinder has remained inside the Outer
Sleeve,push the Piston Rod forward then pull it rearward to
remove the Air Cylinder. CAUTION: handle the Air Cylinder
carefully so as not to damage the inside diameter. Remove
“O” Ring (41535)from the Piston Rod and remove Retaining
Ring (Y145-23).Push Piston Rod and Motor Housing out thru
gear end of Outer Sleeve and remove from Outer Sleeve.
Piston (38867-l) will drop out of Outer Sleevewhen Piston
Rod is removed. Using a suitable rod insert rod thru gearend
of Outer Sleeveand push Muffler Cap (38865)out thru valve
end of Outer Sleeve.Piston Rod and Motor Housing are lock-
ed together with a hard drying thread adhesiveat assembly. If
it should become necessaryto disassemblethese parts, heat
threaded area lightly to facilitate removal - R.H. threads.
REASSEMBLY
NOTE: Whenever a part containing “O” Rings has been
removed from tool it is recommendedthat the “O” Rings be
replaced with new ones when reassembling part to tool.
Lubricate all “O” Rings with “O” Ring lubricant when
assembling.
Assemble Retaining Ring (35619), “O” Rings (Y325-20) and
(Y325-30) and Screen(38886)to Muffler Cap (38865).Assem-
ble Muffler Cap into Outer Sleevefrom end of sleevewith in-
ternal threads with screenend of cap positioned to enter sleeve
first. Push Muffler Cap down into sleeve until it bottoms
against offset in sleeve.Coat Torque Pin (40312-l) with grease
to retain pin in place and assembleinto Outer Sleevein hole
provided. Assemble “O” Ring (Y325-16) to groove in Piston
Rod and assemble “O” Ring (Y325-222) to groove around
Motor Housing. AssemblePiston Rod and Motor Housing in-
to Outer Sleevefrom end of sleevewith external threads, exer-
cising careso asnot to damage “O” Ring (Y325-20) when in-
serting Piston Rod thru Muffler Cap already assembledinto
Sleeve. Slot in Motor Housing must be aligned with Torque
Pin (40312-l). AssembleSeals(38860)to Piston (38867-l) with
lips of seal facing away from each other and assemblePiston
over Piston Rod and push Piston down over Rod until it seats
against step on Rod. Secure with Retaining Ring (Yl45-23).
Assemble “O” Ring (41535) over Piston Rod and push it
down over Rod until it seatsagainst step on rod.
Clamp Valve Housing in a suitable holding device with the
sleeveend upright. Assuming “O” Rings have beenassembled
to Valve Housing; coat I.D. of Air Cylinder (38866-) with
“O” Ring lubricant and placeAir Cylinder on Valve Housing
Over“0” Ring (Y325-29). AssembleMotor and Piston section
with Outer Sleeveto Valve Housing and over Air Cylinder, ex-
ercising careto maintain proper alignment soasnot to damage
I.D. of Air Cylinder and thread Outer Sleeveto Valve Hous-
ing. Tighten securely using a strap type wrench. Assemble
Motor, Gearing and Trip Bracket to tool. Replace Cover
(40313).
SERVICE KIT NO. 45863-1 INCLUDES PISTON ROD, PISTON, SEAL (2), “O” RING Y325-16. RETAINING RING Y 145-23
AND “O” RING 41535.
NOTSHOWN
40312-l TORQUE PIN
40302 NAMEPLATE (NON-EU MODELS)
“O” RING
40302-EU NAMEPLATE (-EU MODELS)
RETAINING RING Y145-23
-“O” RING Y325.16 (2)
PlSTON ROD 40310-l
MOTOR HOUSING 40319
THREAD GUARD 38869 OUTER SLEEVE 40318.1
q “O” RING Y325-20
’ SCREEN 38886 AIR CYLINDER 38866
PISTON 38667
“O”Ring Y325.30
PISTON 8 AIR CYLINDER
PARTS MARKED THUS - ARE INCLUDED IN SERVICE KIT NO. 41325 , SEE PAGE 18.
PAGE 14 OF 20

VALVE SECTION
M104
8257-A-( )
26
DISASSEMBLY
SPOOL VALVE: Remove two (2) Caps (46697) with “0”
Rings (Y325-14). Spool Valve can now be pushed out thru
housing. Handle Spool Valve with reasonablecaresoasnot to
damageoutside diameter of valve.
FEEDCONTROLVALVES:Remove screws (Y211-1)and plate
(48440-l). Unthreadvalvesfrom housingto remove- R.H.thread.
CHECK VALVES (39587): Valve Housing must be removed
from tool to servicecheckvalves. Unthread and removeScrew
Plugs to gain accessto Check Valves and components.
BUTTON BLEED VALVES need not be removed except for
replacement only.
REASSEMBLY
removed from tool it is recommended that the “O” Rings be
replaced with new ones when reassembling part to tool.
Lubricate all “O” Rings with “O” Ring lubricant when
assembling. _/
SPOOL VALVE: Assemble five (5) “O” Rings (41083) to
Valve Body (40307) and assemble Valve Body into housing.
Assemble “O” Rings (Y325-14) to Capsand assembleCapsto
housing.
FEEDCONTROLVALVES:Assemble “O” ring (Y325-7) to needle
valve (48441-1)and assemble needle valve to housing, securing
with plate (48440-l) and screws (Y211-1).
CHECK VALVES: Assemble “O” Ring (Y325-2) to Check
Valve and assembleCheck Valve and Spring (35733)to hous-
ing. Securethe one Check Valve and Spring with Screw Plug
NOTE: Whenever a part containing “O” Rings has been (39652)- seeillustration for correct one. Assemble“O” Ring
(Y325-3)to Screw Plug (38863)and assembleto housing secur-
ing Check Valve and Spring - seeillustration.
HOUSING ASSEMBLY 40814-l
SCR
NEEDLEVALVE (2) 48441-1NEEDLEVALVE (2) 48441-1
“O”RING(3)Y325-15
*ASSEMBLEWITHTHREADADHESIVESUCHASLOCTITE242
PARTS MARKED THUS q ARE INCLUDED IN SERVICE KIT NO. 41325. SEE PAGE18
FORM1681-2 PAGE15OF20

VALVE SECTION
8357-A-( )
Disassemblyand Reassemblyprocedure will be similar to that for Models 8257-A, seepage 15.
HOUSING ASSEMBLY 41302-l
SCREW (2) Y211-1
PLATE48440-l
SCREW PLUG 38863
NEEDLEVALVE 48441-1
VALVE HOUSING-41299-I
PARTS MARKED THUS ARE INCLUDED IN SERVICE KIT NO. 41325 SEE PAGE 18
ACCESSORIES
I I
PAGE16OF20

ACCESSORIESACCESSORIES
38875-l FOOT MOUNT ASS’Y.
38875-l FOOT MOUNT ASS’Y.
M104
26
*NOT INCLUDED IN FOOT MOUNT ASS’Y.
43311 LOCK NUT
FORM 1681-2
PAGE 17 OF 20

ACCESSORIES
43590 EXHAUST MANIFOLD ASSEMBLY
INCLUDES: MANIFOLD 43592, “O” RING (2) 43588 and Set Screw Y23-102.
TO ASSEMBLE TO TOOL: Remove Thread Guard (38869)
from nose end of Outer Sleeveand slip Manifold (43592)-
with “O” Rings (43588) - over Outer Sleeve and position
over exhaust holes in sleeve.Outlet for muffler can be posi-
tioned either to the front or the rear as desired. Tighten Set
Screw (Y23-102) securing manifold to Outer Sleeve. CAU-
TION: DO NOT OVER-TIGHTEN SetScrew (Y23-102) as it
may cause distortion of the Outer Sleeve and thus cause
damage to the Air Cylinder (38866-) contained inside the
Outer Sleeveimpairing the function of the tool.
For external muffling usewith Muffler (43551-3).
For closed exhaust system use with Hose Adapter (22827)
for 1/2” I.D. exhaust hose.
SERVICE KIT NO. 41325
CONSISTINGOF:
PART PART
QTY NO. OESCRlPTION QTY NO. DESCRIPTION
PAGE18OF20
4 30741 Blades
1 Y65-7 Bearing
1 Y325-222 O-Ring
2 Y325-16 O-Ring
1 Y325-20 O-Ring
1 41535 O-Ring
2 38860 Seal
1 Y325-30 O-Ring
1 Y325-3 O-Ring
2 Y325-7 O-Ring
3 40309 Gasket
Y325-15 O-Ring
1 ‘Y65-15 Bearing
35733 Spring
Y325-2 O-Ring
41083 O-Ring
Y325-29 O-Ring
Y325-129 O-Ring
38783 Cap
Y325-14 O-Ring
31363 Blades
41795 Motor Oil
41799 Gear Lube
41954 O-Ring Lube

TROUBLE SHOOTING
M104
26
LISTED BELOW ARE SOME OF THE MOST COMMON CAUSES FOR THE SELF-FEED TAPPER TO MALFUCTION. MALFUNCTIONS
BEYOND THE SCOPE OF THIS MANUAL SHOULD BE BROUGHT TO THE ATTENTION OF YOUR ARO REPRESENTATIVE OR THE TOOL
RETURNED TO FACTORY FOR REPAIR.
-
CONDITION
FAILURE TO
FEED OR
IRREGULAR OR
ERRATIC FEED.
LOW SPEED OR
MOTOR FAILS TO
OPERATE.
MOTOR CONTINUE!
TO RUN AFTER
RETRACTION.
FAILURE TO
RETRACT.
POSSIBLE CAUSE CORRECTIVE ACTION
1. INADEQUATE AIR
SUPPLY. 1. CHECK AIR SUPPLY FOR CORRECT REGULATOR AD-
JUSTMENT (90 P.S.I.G. MAX. WHEN TOOL IS
OPERATING).
2. FEED CONTROL
VALVES IMPROPERLY
ADJUSTED.
2. REFER TO SET-UP PROCEDURE PAGE 4.
3. AIR LEAK AROUND
CAP 46697 3. CHECK FOR DAMAGE TO “0” RING. CHECK AND INSURE
CAPS ARE PROPERLY TIGHTENED.
4. DIRT OR DAMAGED
“0” RINGS ON SPOOL
-VALVE 40307
4. REFER TO VALVE SECTION PAGE 15 AND REMOVE
SPOOL VALVE. INSPECT, CLEAN, REPLACE “O” RINGS.
5. CLOGGED AIR PASSAGE
IN VALVE HOUSING. 5. REMOVE VALVE HOUSlNG FROM TOOL. DISASSEMBLE,
BLOW ALL AIR PASSAGES CLEAR OF DEBRIS.
1. INADEQUATE AIR 1.
SUPPLY. CHECK AIR SUPPLY FOR CORRECT REGULATOR AD-
JUSTMENT.
2. CLOGGED AIR
PASSAGE IN VALVE
HOUSING.
2. REMOVE VALVE HOUSING FROM TOOL. DISASSEMBLE,
BLOW AIR PASSAGES CLEAR OF DEBRIS.
1. PISTON NOT FULLY
RETRACTED. 1. INSURE PISTON IS NOT OBSTRUCTED AND IS
RETURNED ALL THE WAY BACK.
2. DAMAGED “0” RING
Y325-15 INSIDE VALVE
HOUSING.
2. REMOVE VALVE HOUSING FROM TOOL. REPLACE “0”
RINGS.
1. IMPROPER ADJUSTMENT
OR ALIGNMENT BETWEEN
ADJUSTMENT SCREW
AND BUTTON BLEED VALVE.
1. REFER TO SET-UP PROCEDURE PAGE 4.
2. FEED CONTROL VALVES
46441-l IMPROPERLY
ADJUSTED OR DIRTY.
2. CHECK ADJUSTMENT, REFER TO PAGE 4. REMOVE, IN-
SPECT, CLEAN.
3. AIR LEAK AROUND
CAP 46697 3. CHECK FOR DAMAGE TO “0” RING. CHECK AND INSURE
CAPS ARE PROPERLY TIGHTENED.
4. DAMAGED “0” RINGS
IN MUFFLER CAP,
VALVE HOUSING OR
SPOOL VALVE OR SEALS
ON PISTON.
4. DISASSEMBLE, INSPECT, REPLACE “0” RINGS AND/OR
SEALS.
5. CLOGGED AIR PASSAGE
IN VALVE HOUSING. 5. REMOVE VALVE HOUSING FROM TOOL. DISASSEMBLE,
BLOW AIR PASSAGES CLEAR OF DEBRIS.
FORM 1681-2 PAGE 19 OF 20

I
MODEL NO. R.P.M. TOTAL RED.
OPTIONAL FORWARD PISTON
INLET PORT 1/8-27 N.P.T.F.
-OPTIONAL RETURN PISTON
INLET PORT 1/8-27 N.P.T.F.
)-P-9/16(65ru)----)
OPTION CHUCK NO. CAPACITY “A” “B”
-B 31427 0-1/4 1-15/16 (49mm) 1-3/32(28mm)
-A 31432 *10-5/16 1-15/16 (49mm) 1-3/32(28mm)
-C 32060 5/16-5/8 2-7/16 (62mm) 1-15/32(37mm)
*HAND TAP
MANUAL BLEED
BUTTON 1
t