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PP20A-XXX-XXX (en)
PARTS LIST / PP20A-XXX-XXX AIR MOTOR SECTION
Indicates parts included in 637421 air section repair kit, plus items 70, 144, 175 and 180 (page 6).
MATERIAL CODE
[A] = Aluminum
[C] = Carbon Steel
[SS] = Stainless Steel
[B] = Nitrile
[Ck] = Ceramic
[U] = Polyurethane
[Br] = Brass
[D] = Acetal
[Bz] = Bronze
[Sp] = Santoprene
AIR MOTOR SECTION SERVICE
Service is divided into two parts - 1. Pilot Valve, 2. Major
Valve.
GENERAL REASSEMBLY NOTES:
Air motor section service is continued from fl uid section
repair.
Inspect and replace old parts with new parts as neces-
sary. Look for deep scratches on metallic surfaces, and
nicks or cuts in “O” rings.
Take precautions to prevent cutting “O” rings upon instal-
lation.
Lubricate “O” rings with Lubriplate FML-2 grease.
Do not over-tighten fasteners, refer to torque specifica-
tion block on view.
Re-torque fasteners following re-start.
Service Tools - To aid in the installation of (168) “O” rings
onto the (167) pilot piston, use tool #204130-T, available
from ARO.
PILOT VALVE DISASSEMBLY
A light tap on (118) should expose the opposite (121)
sleeve, (167) pilot piston and other parts.
Remove (170) sleeve. Inspect inner bore of sleeve for
damage.
PILOT VALVE REASSEMBLY
Clean and lubricate parts not being replaced from service
kit.
Install new (171 and 172) “O” rings. Replace (170) sleeve.
1.
2.
1.
2.
Install new (168) “O” rings and (169) seal - Note the lip di-
rection. Lubricate and replace (167) pilot piston.
Reassemble remaining parts. Replace (173 and 174) “O”
rings.
MAJOR VALVE DISASSEMBLY
Remove (135) valve block and (233) adapter plate, expos-
ing (166 and 132) gaskets and (176) checks.
Remove (233) adapter plate, releasing (140) valve insert,
(141) valve plate, (199, 200 and 241) gaskets and (231,
243 and 244) “O” rings.
Remove (136) plug and (137) “O” ring, releasing (111)
spool.
MAJOR VALVE REASSEMBLY
Install new (138 and 139) “U” cups on (111) spool - LIPS
MUST FACE EACH OTHER.
Insert (111) spool into (135) valve housing.
Install (137 and 242) “O” rings on (136) plug and assemble
plug to (135) valve housing, securing with (105) screws.
Install (140) valve insert, (141) valve plate, (199) gasket
and (231, 243 and 244) “O” rings into (135) valve hous-
ing. NOTE: Assemble (140) valve insert with “dished” side
toward (141) valve plate. Assemble (141) valve plate with
part number identifi cation toward (140) valve insert.
Assemble (200 and 241) gaskets and (233) adapter plate
to (135) valve housing, securing with (240) screws. NOTE:
Tighten screws to 40 - 50 in. lbs (4.5 - 5.6 Nm).
Assemble (132 and 166) gaskets and (176) checks to (101)
center body.
Assemble (135) valve housing and components to (101)
center body, securing with (134) screws. NOTE: Tighten
screws to 40 - 50 in. lbs (4.5 - 5.6 Nm).
3.
4.
1.
2.
3.
1.
2.
3.
4.
5.
6.
7.
AIR MOTOR PARTS LIST
Item Description
(size)
(Qty) Part No.
[Mtl]
Item Description
(size)
(Qty) Part No.
[Mtl]
101 Center Body
(1) 94028
[A]
103 Bushing
(1) 95955
[Bz]
105 Screw
(M6 x 1 - 6g x 20 mm)
(4) 95887
[SS]
111 Spool
(1) 95651
[D]
118 Actuator Pin
(0.250” x 2.276” long)
(2) 94083
[SS]
121 Sleeve
(2) 94084
[D]
128 Set Screw
(1/4” - 20 x 1/4”)
(2) Y29-42-S
[SS]
132 Gasket
(1) 94099
[B]
133 Lockwasher
(1/4”)
(4) Y117-416-C [C]
134 Screw
(M6 x 1 - 6g x 30 mm)
(4) 96358
[SS]
135 Valve Housing
(1) 96346
[A]
136 Plug
(1) 96335
[A]
137 “O” Ring
(1/16” x 2” o.d.)
(1) Y325-32
[B]
138 “U” Cup
(3/16” x 1.792” o.d.)
(1) 95966
[B]
139 “U” Cup
(3/16” x 1-1/4” o.d.)
(1) Y186-50
[B]
140 Valve Insert
(1) 95650
[Ck]
141 Valve Plate
(1) 95659
[Ck]
166 Track Gasket
(1) 94026
[B]
167 Pilot Piston
(includes 168 and 169)
(1) 67164
[D]
168 “O” Ring
(3/32” x 5/8” o.d.)
(2) 94433
[U]
169 “U” Cup
(1/8" x 7/8" o.d.)
(1) Y240-9
[B]
170 Piston Sleeve
(1) 94081
[Br]
171 “O” Ring
(3/32” x 1-1/8” o.d.)
(1) Y325-119
[B]
172 “O” Ring
(1/16” x 1-1/8” o.d.)
(1) Y325-22
[B]
173 “O” Ring
(1/16” x 1-3/8” o.d.)
(2) Y325-26
[B]
174 “O” Ring
(1/8” x 1/2” o.d.)
(2) Y325-202
[B]
176 Diaphragm
(check valve)
(2) 94102
[Sp]
199 Track Gasket
(1) 95666
[B]
200 Gasket
(1) 95665
[B]
201 Muffl
er
(1) 94117
[C]
231 “O” Ring
(3/32” x 11/32” o.d.)
(2) Y325-105
[B]
233 Adapter Plate
(1) 96347
[A]
240 Screw
(M6 x 1 - 6g x 16 mm)
(2) 95991
[SS]
241 Track Gasket
(1) 96344
[B]
242 “O” Ring
(1/16” x 7/32” o.d.)
(1) Y325-5
[B]
243 “O” Ring
(1/8” x 5/8” o.d.)
(1) Y325-204
[B]
244 “O” Ring
(1/8” x 7/8” o.d.)
(1) Y325-208
[B]
255 Pipe Plug
(1/16 - 27 N.P.T. x 1/4”)
(2) Y227-1-L
[C]
Lubriplate FML-2 Grease
(1) 94276
Lubriplate Grease, 10 Pack
637308
