Page 6 of 8
PD20X-XXX-XXX-B (en)
MATERIAL CODE
[A] = Aluminum
[D] = Acetal
[B] = Nitrile
[I] = Iron
[Br] = Brass
[Sp] = Santoprene
[C] = Carbon Steel
[SS] = Stainless Steel
[Ck] = Ceramic
[U] = Polyurethane
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 Fluid Section repair.
Inspect and replace old parts with new parts as necessary. Look
for deep scratches on metallic surfaces, and nicks or cuts in “O”
rings.
Take precautions to prevent cutting “O” rings upon installation.
Lubricate “O” rings with Lubriplate FML-2 grease.
Do not over-tighten fasteners. Refer to torque specifi cation
block on view.
Re-torque fasteners following restart.
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) actuator pin 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.
y
y
y
y
y
y
y
1.
2.
1.
2.
Install new (168) “O” rings and (169) seal - Note the lip direction.
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, exposing
(132 and 166) gaskets and (176) checks.
Remove (233) adapter plate, releasing (140) valve insert, (141)
valve plate, (199, 200 and 241) gaskets and (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 block.
Install (137 and 242) “O” rings on (136) plug and assemble plug
to (135) valve block, securing with (105) screws.
Install (140) valve insert, (141) valve plate, (199) gasket and (243
and 244) „O“ rings into (135) valve block. NOTE: Assemble (140)
valve insert with “dished” side toward (141) valve plate. Assem-
ble (141) valve plate with part number identification toward
(140) valve insert.
Assemble (200 and 241) gaskets and (233) adapter plate to (135)
valve block, securing with (240) screws.
Assemble (132 and 166) gaskets and (176) checks to (101) cen-
ter body.
Assemble (135) valve block and components to (101) center
body, securing with (134) screws.
3.
4.
1.
2.
3.
1.
2.
3.
4.
5.
6.
7.
PARTS LIST / PX20X-XXX-XXX-B( ) AIR MOTOR SECTION
AIR MOTOR PARTS
Item
Description
(size)
Qty Part No.
Mtl
101 Center Body
(PX20A-XXX-XXX-B)
(1)
94028
[A]
(PX20S-XXX-XXX-B)
(1)
94109
[SS]
103 Bushing
(1)
94092
[D]
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]
127 90° St. Elbow
(1-1/2 - 11-1/2 N.P.T.)
(1)
94860
[C / I]
128 Set Screw
(1/4” - 20 x 1/4”)
(2)
Y29-42-S
[SS]
o
132 Gasket
(1)
94099
[B]
133 Lockwasher
(1/4”) (PX20A-XXX-XXX-B)
(3)
Y117-416-C
[C]
(PX20S-XXX-XXX-B)
(3)
Y14-416-T
[SS]
134 Screw
(M6 x 1 - 6g x 30 mm)
(4)
96358
[SS]
135 Valve Housing
(PD20A-XXX-XXX-B)
(1)
96334-1
[A]
(PD20S-XXX-XXX-B)
(1)
96337-1
[SS]
(PE20A-XXX-XXX-B)
(1)
96334-2
[A]
(PE20S-XXX-XXX-B)
(1)
96337-2
[SS]
136 Plug
(PX20A-XXX-XXX-B)
(1)
96335
[A]
(PX20S-XXX-XXX-B)
(1)
96339
[SS]
o
137 “O” Ring
(1/16” x 2” o.d.)
(1)
Y325-32
[B]
o
138 “U” Cup
(3/16” x 1.792” o.d.)
(1)
95966
[B]
o
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)
so
146 “O” Ring
(3/32” x 1-1/16” o.d.)
(1)
Y325-118
[B]
so
147 “O” Ring
(1/8” x 1/2” o.d.)
(2)
Y325-202
[B]
Item
Description
(size)
Qty Part No.
Mtl
to
166 Track Gasket
(1)
94026
[B]
o
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]
o
171 “O” Ring
(3/32” x 1-1/8” o.d.)
(1)
Y325-119
[B]
o
172 “O” Ring
(1/16” x 1-1/8” o.d.)
(1)
Y325-22
[B]
o
173 “O” Ring
(1/16” x 1-3/8” o.d.)
(2)
Y325-26
[B]
no
174 “O” Ring
(1/8” x 1/2” o.d.)
(2)
Y325-202
[B]
o
176 Diaphragm
(check valve)
(2)
94102
[Sp]
o
199 Track Gasket
(1)
95666
[B]
o
200 Gasket
(1)
95665
[B]
201 Muffl
er Kit
(includes item 127)
(1)
67213
233 Adapter Plate
(PX20A-XXX-XXX-B)
(1)
96336
[A]
(PX20S-XXX-XXX-B)
(1)
96338
[SS]
240 Screw
(M6 x 1 - 6g x 16 mm)
(2)
95991
[SS]
o
241 Track Gasket
(1)
96344
[B]
o
242 “O” Ring
(1/16” x 7/32” o.d.)
(1)
Y325-5
[B]
o
243 “O” Ring
(1/8” x 5/8” o.d.)
(1)
Y325-204
[B]
o
244 “O” Ring
(1/8” x 7/8” o.d.)
(1)
Y325-208
[B]
n
o
Lubriplate FML-2 grease
(1)
94276
Lubriplate Grease Packets (10)
637308
n
Items included in fl uid section service kit, see pages 4 and 5.
s
Used on models PX20S-XXX-XXX-B( ) only.
t
Used on models PX20A-XXX-XXX-B( ) only.
o
Indicates parts included in 637421 air section service kit shown below and items (70), (144), (175) and (180) shown on page 4.
