ARO PD20 series, Operator'S Manual

Page: 7 / 12

PX20X-XXX-XXX-BXXX (en) Page 7 of 12
PARTS LIST / PX20X-XXX-XXX-BXXX AIR MOTOR SECTION

Indicates parts included in 637421 air section service kit shown below and items (70), (144), (175) and (180) shown on page 5.
Item Description
(size)
Qty Part No. Mtl
76 Pipe Plug
( 1/8 - 27 N.P.T x 0.27")
(1) Y17-50-S [SS]
101 Center Body
(PX20A-XXX-XXX-BXXX)
(1) 97031 [A]
(PX20S-XXX-XXX-BXXX)
(1) 97040 [SS]
103 Bushing (1) 97394 [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]

132 Gasket (1) 94099 [B]
133 Lockwasher
(1/4”)
(PX20A-XXX-XXX-BXXX)
(3) Y117-416-C [C]
133
(PX20S-XXX-XXX-BXXX)
(3) Y14-416-T [SS]
134 Screw
(M6 x 1 - 6g x 35 mm)
(4) 95923 [SS]
135 Valve Block
(PD20A-XXX-XXX-BXXX)
(1) 96334-1 [A]
(PD20S-XXX-XXX-BXXX)
(1) 96337-1 [SS]
(PE20A-XXX-XXX-BSXX)
(1) 96334-2 [A]
(PE20S-XXX-XXX-BSXX)
(1) 96337-2 [SS]
136 Plug
(PX20A-XXX-XXX-BXXX)
(1) 96335 [A]
(PX20S-XXX-XXX-BXXX)
(1) 96339 [SS]

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 [AO]
141 Valve Plate (1) 95659 [AO]

146 “O” Ring
(3/32” x 1-1/16” o.d.)
(1) Y325-118 [B]

147 “O” Ring
(1/8” x 1/2” o.d.)
(2) Y325-202 [B]
Item Description
(size)
Qty Part No. Mtl

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 [D]

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 Muffler Kit
(includes item 127)
(1) 67213
233 Adapter Plate
(PX20A-XXX-XXX-BXXX)
(1) 96336 [A]
(PX20S-XXX-XXX-BXXX)
(1) 96338 [SS]
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]
 
Lubriplate FML-2 grease (1) 94276
Lubriplate Grease Packets (10) 637308
 Items included in fluid section service kit, see pages 5 and 6.
 Used on models PX20S-XXX-XXX-BXXX only.
 Used on models PX20A-XXX-XXX-BXXX only.
AIR MOTOR SECTION SERVICE
Service is divided into two parts - 1. Pilot Valve, 2.
Major Valve.
GENERAL REASSEMBLY NOTES:
y
Air Motor Section service is continued from Fluid Section
repair.
y
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.
y
Take precautions to prevent cutting “O” rings upon instal-
lation.
y
Lubricate “O” rings with Lubriplate FML-2 grease.
y
Do not over-tighten fasteners. Refer to torque specifi-
cation block on view.
y
Re-torque fasteners following restart.
y
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
1. A light tap on (118) actuator pin should expose the oppo-
site (121) sleeve, (167) pilot piston and other parts.
2. Remove (170) sleeve. Inspect inner bore of sleeve for
damage.
PILOT VALVE REASSEMBLY
1. Clean and lubricate parts not being replaced from service
kit.
2. Install new (171 and 172) “O” rings. Replace (170) sleeve.
3. Install new (168) “O” rings and (169) "U" cup - Note the lip
direction. Lubricate and replace (167) pilot piston.
4. Reassemble remaining parts. Replace (173 and 174)
“O” rings.
MATERIAL CODE
[A] = Aluminum
[AO] = Alumina Oxide
[B] = Nitrile
[Br] = Brass
[C] = Carbon Steel
MATERIAL CODE
[D] = Acetal
[I] = Iron
[SP] = Santoprene
[SS] = Stainless Steel
[U] = Polyurethane
MAJOR VALVE DISASSEMBLY
1. Remove (135) valve block and (233) adapter plate, expos-
ing (132 and 166) gaskets and (176) checks.
2. Remove (233) adapter plate, releasing (140) valve insert,
(141) valve plate, (199, 200 and 241) gaskets and (243 and
244) “O” rings.
3. Remove (136) plug and (137) “O” ring, releasing (111)
spool.
MAJOR VALVE REASSEMBLY
1. Install new (138 and 139) “U” cups on (111) spool - LIPS
MUST FACE EACH OTHER.
2. Insert (111) spool into (135) valve block.
3. Install (137 and 242) “O” rings on (136) plug and assemble
plug to (135) valve block, securing with (105) screws.
4. 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. Assemble (141) valve plate with part
number identification toward (140) valve insert.
5. Assemble (200 and 241) gaskets and (233) adapter plate
to (135) valve block, securing with (240) screws.
6. Assemble (132 and 166) gaskets and (176) checks to (101)
center body.
7. Assemble (135) valve block and components to (101)
center body, securing with (134) screws.