Graco Dyna-Star 26A938 User manual

Manual 3A7718A
EN
Instructions/Parts
Dyna-Star®Pump
Air Motors
For use on Dyna-Star Air Motor piston pumps, which are used in grease transfer
applications. For professional use only.
Model 26A938, Series A, 7.5 in. Air Motor
Model 26A939, Series A, 6.0 in. Air Motor
See page 3 for model information, including maximum
working pressure and approvals.
Related Manuals
Important Safety Instructions
Read all warnings and instructions in this
manual and in your pump or package
manual before using the equipment. Save
all instructions.
Manual
(English) Description
3A7519 Dyna-Star 200:1 and Dyna-Star 120:1
Grease Pumps

2Manual 3A7718A
Contents
Related Manuals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Component Identification . . . . . . . . . . . . . . . . . . . . . . 6
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Recycling and Disposal . . . . . . . . . . . . . . . . . . . . . . . 8
End of Product Life . . . . . . . . . . . . . . . . . . . . . . . 8
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Preventive Maintenance Schedule . . . . . . . . . . 10
Pressure Relief Procedure . . . . . . . . . . . . . . . . . 10
Repair Air Valve . . . . . . . . . . . . . . . . . . . . . . . . . 10
Replace Complete Air Valve......................... 10
Replace Seals or Repair Air Valve. . . . . . . . . . . 11
Disassemble the Air Valve............................ 11
Reassemble the Air Valve ............................ 12
Replace Pilot Valves..................................... 12
Repair Air Motor . . . . . . . . . . . . . . . . . . . . . . . . . 13
Disassemble the Air Motor ........................... 13
Reassemble the Air Motor ............................ 13
Notes: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Air Motor Seal Kits . . . . . . . . . . . . . . . . . . . . . . . 18
Air Valve Parts . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Air Valve Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Technical Specifications . . . . . . . . . . . . . . . . . . . . . . 21
California Proposition 65 . . . . . . . . . . . . . . . . . . . . . 21
Graco Standard Warranty. . . . . . . . . . . . . . . . . . . . . 22

Models
Manual 3A7718A 3
Models
Check the motor’s identification plate (ID) for the 6-digit
part number.
*Not sale-able part numbers.
FIG. 1
ID
Air Motor
Part Number
Replacement
Air Motor Part
Number Series
Stroke
(in.)
Piston Diameter
in. (mm)
Maximum Air Inlet Pressure
psi (MPa, bar)
26A938* 25T843 A 4.75 7.5 (191) 100 psi (0.7 MPa, 7.0 bar)
26A939* 25T844 A 4.75 6.0 (152) 100 psi (0.7 MPa, 7.0 bar)

Warnings
4Manual 3A7718A
Warnings
The following warnings are for the setup, use, grounding, maintenance, and repair of this equipment. The
exclamation point symbol alerts you to a general warning and the hazard symbols refer to procedure-specific risks.
When these symbols appear in the body of this manual or on warning labels, refer back to these Warnings.
Product-specific hazard symbols and warnings not covered in this section may appear throughout the body of this
manual where applicable.
WARNING
MOVING PARTS HAZARD
Moving parts can pinch, cut or amputate fingers and other body parts.
• Keep clear of moving parts.
• Do not operate equipment with protective guards or covers removed.
• Equipment can start without warning. Before checking, moving, or servicing equipment, follow the
Pressure Relief Procedure and disconnect all power sources.
FIRE AND EXPLOSION HAZARD
When flammable fluids are present in the work area, such as gasoline and windshield wiper fluid, be
aware that flammable fumes can ignite or explode. To help prevent fire and explosion:
• Use equipment only in well-ventilated area.
• Eliminate all ignition sources, such as cigarettes and portable electric lamps.
• Ground all equipment in the work area.
• Keep work area free of debris, including rags and spilled or open containers of solvent and gasoline.
• Do not plug or unplug power cords or turn lights on or off when flammable fumes are present.
• Use only grounded hoses.
•Stop operation immediately if static sparking occurs or you feel a shock.Do not use equipment until
you identify and correct the problem.
• Keep a working fire extinguisher in the work area.

Warnings
Manual 3A7718A 5
EQUIPMENT MISUSE HAZARD
Misuse can cause death or serious injury.
• Do not operate the unit when fatigued or under the influence of drugs or alcohol.
• Do not exceed the maximum working pressure or temperature rating of the lowest rated system
component. See Technical Specifications in all equipment manuals.
• Use fluids and solvents that are compatible with equipment wetted parts. See Technical
Specifications in all equipment manuals. Read fluid and solvent manufacturer’s warnings. For
complete information about your material, request Safety Data Sheets (SDSs) from distributor or
retailer.
• Turn off all equipment and follow the Pressure Relief Procedure when equipment is not in use.
• Check equipment daily. Repair or replace worn or damaged parts immediately with genuine
manufacturer’s replacement parts only.
• Do not alter or modify equipment. Alterations or modifications may void agency approvals and create
safety hazards.
• Make sure all equipment is rated and approved for the environment in which you are using it.
• Use equipment only for its intended purpose. Call your distributor for information.
• Route hoses and cables away from traffic areas, sharp edges, moving parts, and hot surfaces.
• Do not kink or over bend hoses or use hoses to pull equipment.
• Keep children and animals away from work area.
• Comply with all applicable safety regulations.
PERSONAL PROTECTIVE EQUIPMENT
Wear appropriate protective equipment when in the work area to help prevent serious injury, including
eye injury, hearing loss, inhalation of toxic fumes, and burns. Protective equipment includes but is not
limited to:
• Protective eyewear, and hearing protection.
• Respirators, protective clothing, and gloves as recommended by the fluid and solvent manufacturer.
WARNING

Component Identification
6Manual 3A7718A
Component Identification
Key:
Air Motor Kit Components
A Air valve
B Pilot valve (bottom pilot valve is out of view)
C Top cover
D Bottom cover
E Manifold
F Ground screw
Lift Ring, Shrouds, and fittings
G Air inlet, 1/2 in. npt(f)
H Air outlet 3/4 in. npt
J Lift ring
FIG. 2: Typical Installation
J
A
B
C
D
E
F
G
H

Component Identification
Manual 3A7718A 7
Grounding
Air Motor: use ground wire and clamp (Graco P/N
222011, not supplied), as shown in FIG. 1.
1. Connect the ground wire (Y) to the ground screw (Z)
located on the bottom of the air motor.
2. Connect the other end of the ground wire (Y) to a
true earth ground.
The equipment must be grounded to reduce the risk
of static sparking. Static sparking can cause fumes to
ignite or explode. Grounding provides an escape wire
for the electric current.
FIG. 3
Y
Z

Recycling and Disposal
8Manual 3A7718A
Recycling and Disposal
End of Product Life
At the end of a product’s useful life, recycle it in a
responsible manner.

Troubleshooting
Manual 3A7718A 9
Troubleshooting
1. Relieve pressure before checking or servicing the
equipment, following the pressure relief procedure
for your system.
NOTE: Check all possible problems and causes before
disassembling the air motor.
Problem Cause Solution
Air motor will not run. Damaged air valve (17). Replace or service air valve (17),
see page 18.
Damaged pilot valve (19). Replace pilot valves (19), see page
12.
Air continuously exhausting around
air motor piston rod.
Damaged u-cups (3, 33) Replace piston rod u-cups (3, 33),
see page 13.
Air continuously exhausting muffler. Damaged air valve plate (105) or
cup (112)
Replace or service air valve (17),
see page 10.
Damaged piston o-rings (8) Replace the seals, see page 13.
Air motor “bounces” at top of
stroke.
Damaged bottom pilot valve. Replace bottom pilot valve (19),
see page 12.
Air motor “bounces” at bottom of
stroke.
Damaged top pilot valve. Replace top pilot valve (19), see
page 12.
Icing inside the motor. Air motor is operating at high
pressure or high cycle rate.
Reduce pressure, cycle rate, or
duty cycle of motor.
Reduce the dew point of
compressed air by using a moisture
coalescing filter.

Repair
10 Manual 3A7718A
Repair
Preventive Maintenance
Schedule
The operating conditions of the system determine how
often maintenance is required. Establish a preventative
maintenance schedule by keeping a record of when and
what type of maintenance is needed, and then
determine a regular schedule for checking the system.
Pressure Relief Procedure
1. Turn off the air supply to the pump.
2. Close the bleed-type master valve (required).
3. Open the fluid ball valve and/or dispensing valve to
relieve fluid pressure.
Repair Air Valve
Refer to Parts, on page 16 for this section.
Replace Complete Air Valve
1. Stop the pump in the middle of its stroke. Follow
Pressure Relief Procedure, page 10.
2. Disconnect the air lines.
3. Remove screws (18), see Parts, page 16.
4. Remove the air valve (17) and gasket (16).
5. To repair the air valve, start at Disassemble the Air
Valve, page 11, step 1. To install a replacement
valve, continue to step 6.
6. Lubricate and align the new air valve gasket (16) on
the manifold.
7. Lubricate the air valve plate (105), then attach the
air valve (17) (torque 95 - 105 in-lb/10.7 - 11.9 N•m).
• Trapped air can cause the pump to cycle
unexpectedly, which could result in serious injury
from moving parts,
• Relieve pressure when stopping the pump and
before cleaning, checking, or servicing equipment.
• Do not lift or move the motor while pressurized.

Repair
Manual 3A7718A 11
Replace Seals or Repair Air
Valve
NOTE:
• Air Valve Seal Kits are available. To order the
correct kit for the pump, see page 19 (parts are
marked with an †).
• Air Valve Repair Kits are available. To order the
correct kit for the pump, see page 19 (parts are
marked with an ).
• Air Valve End Cap Kits are available. To order the
correct kit for the pump, see page 19 (parts are
marked with an ).
Disassemble the Air Valve
1. Perform steps 1 - 4 from Replace Complete Air
Valve, page 10.
2. Use a 2 mm or 5/64 hex key to remove the two
screws (109) (FIG. 4).
3. Remove the valve plate (105), cup (112), and spring
(111) (FIG. 4).
4. Remove the snap ring (110) from each end (FIG. 5).
5. Use the piston and push the end caps (107) out of
each end (FIG. 5).
6. Remove the end cap o-rings (106) (FIG. 5).
7. Remove the piston (102) (FIG. 5).
8. Remove the u-cup seals (108) from each end (FIG.
5).
9. Remove the detent assembly (103) and detent cam
(104) from the center (FIG. 5).
FIG. 4
109
105 112 111
FIG. 5
109
104
112
101
103
1
Apply lubricant.
1
111
1
105
108
1
102
108
1
107
106
1
110
110
106
1
107

Repair
12 Manual 3A7718A
Reassemble the Air Valve
1. Lubricate detent cam (104) and install into housing.
2. Lubricate the u-cups (108) and install on the piston
(103) with the lips facing the center of the piston.
3. Lubricate both ends of the piston (102) and install it
into the housing.
4. Lubricate the detent assembly (103) and install it
into the piston.
5. Lubricate new o-rings (106) and install on the end
caps (107) and install the end caps into the housing.
6. Install a snap ring (110) onto each end to held the
end caps in place.
7. Install the spring (111).
8. Lubricate and install the air valve cup (112).
9. Align the small round magnet with the air inlet.
10. Install the valve plate (105), then tighten the screws
(109) to hold in place.
Replace Pilot Valves
1. Stop the pump in the middle of its stroke. Follow
Pressure Relief Procedure, page 10.
2. Disconnect the air line to the motor.
3. Use a 10 mm socket wrench to remove the old pilot
valves (19) from the top and bottom covers.
4. Lubricate and install the new pilot valves (19)
(torque 95 - 105 in-lb/10.7 - 11.9 N•m).
FIG. 6
108
108
102
Lips Face Up
Lips Face Down
FIG. 7
112
Magnet

Repair
Manual 3A7718A 13
Repair Air Motor
Refer to Parts, on page 16 for this section.
NOTE: Air Motor Seal Kits are available. To order the
correct kit for the pump, see page 18. Parts included in
the kit are marked with an (*). For best results, use all of
the parts in the kit.
Disassemble the Air Motor
1. Stop the pump in the middle of its stroke. Follow
Pressure Relief Procedure, page 10.
2. Disconnect the air lines.
3. Use a 10 mm socket wrench to remove four screws
(18), then remove the air valve (17) and gasket (16).
4. Remove four screws (18) to remove the manifold
(15) and gasket (14).
5. Use a 10 mm socket wrench to remove the pilot
valves (19) from the top and the bottom covers.
6. Remove the lift ring (31) and o-ring (32) from the
center of the top cover.
7. Remove the tie bolts (10).
8. Remove the top cover and take out the o-ring (9).
9. Remove the cylinder (11).
10. Slide the piston assembly (5) straight up and off of
the bottom cover.
11. Remove the o-ring (8) from around the piston.
12. Remove the retaining ring (4), the u-cup seals (3,
33), and the o-ring (9) from the bottom cover.
Reassemble the Air Motor
NOTE: Use NLGI No. 1, bentone-based grease for
lubricant.
For easier reassembly, begin with the top cover (13)
turned over on the workbench then reassemble the air
motor from top to bottom.
1. Lubricate and install the o-ring (9) onto the top cover
(13).
2. Lubricate the inside of the cylinder (11) then lower
the cylinder (11) onto the top cover (13).
3. Lubricate then install the o-ring (8) around the
piston assembly (5).
4. Slide the piston assembly (5) down onto the cylinder
(11), making sure that the o-ring (9) stays in place.
5. Lubricate then install a new u-cup seal with flange
(33) in the bottom of the bearing located in the
bottom cover (1), making sure that the u-cup faces
up and the flange faces down. Then lubricate and
install a new u-cup seal (3) in the top of the bearing
making sure that the u-cup lips are facing up (FIG.
8).
6. Install the retaining ring (4).
7. Lubricate and install the o-ring (9) onto the bottom
cover (1).
8. Place the bottom cover (1) carefully onto the
cylinder (11), sliding the rod through the bearing.
The manifold surfaces of the top and bottom covers
must align.
9. Install the tie bolts (10) and hand tighten.
NOTICE
To prevent damage, do not attempt to take apart the
piston assembly (5). FIG. 8
3
Lips Face Up
33
Lips Face Up
4

Repair
14 Manual 3A7718A
10. Install two gaskets (14) on the manifold (15).
11. Install the manifold (15) (torque 95 - 105 in-lb/10.7 -
11.9 N•m).
12. Align the air valve gasket (16) on the manifold, then
attach the air valve.
13. Tighten the tie bolts (10) halfway. Work in a
criss-cross pattern. Continue to tighten the bolts in
criss-cross pattern and torque to 25 - 30 ft.-lb/33.9 -
40.7 N•m).
14. Lubricate and install pilot valves (19) into the top
and bottom covers (torque 95 - 105 in-lb/10.7 - 11.9
N•m).
15. Install the lift ring (31) and o-ring (32) in the center
of the top cover (13). Lubricate the o-ring.

Notes:
Manual 3A7718A 15
Notes:

Parts
16 Manual 3A7718A
Parts
Torque to 25-30 ft.-lb (33.9-40.7 N•m)
1
2
4
Apply NLGI No. 1, bentone-based grease.
31
19
32
2
4
13
29
5
9*
2
11
8*
2
5
3*
2
9*
2
28
33*
2
4*
19
2
4
10
1
1
14*
18
4
16*
18
4
17
15
Torque to 95-105 in-lb (10.7-11.9 N•m)
Press to snap fit.
2
2
5
29
30
Upper Bumper - Only used
on Air Motor Model 26A938
3
U-cup faces up. Flange (bottom seal only)
faces down. See FIG. 8, page 13.
3
3
Torque to 30-35 ft.-lb (40.7-47.5 N•m)
6
6
2

Parts
Manual 3A7718A 17
Air Motor Parts - All Models
* Parts included in Air Motor Seal Kit (purchase separately),
see page 18.
Included in Air Valve Repair Kit (purchase separately), see
page 19.
‡ The upper cover assembly includes two adapter o-rings.
See Ref. 32 for the correct o-ring for use with your motor.
Ref. Description Qty. Model 26A939 Model 26A938
1 Cover, lower, assembly; includes Refs. 3, 4, 9,
12, 19, 28, and 33
1 24A549 24A553
3* U-cup 1 Not sold separately. See Air Motor Seal Kits, page
18 or Lower Cover Assembly (Ref. 1, this table)
4* Retaining ring 1 Not sold separately. See Air Motor Seal Kits, page
18 or Lower Cover Assembly (Ref. 1, this table)
5 Piston/Rod, assembly 1
8* O-ring, piston 1 Not sold separately. See Air Motor Seal Kits, page
18 or Lower Cover Assembly (Ref. 1, this table)
9* O-ring, cover 2 Not sold separately. See Air Motor Seal Kits, page
18 or Lower Cover Assembly (Ref. 1, this table)
10 Bolt, tie, hex head 4
6
15M315 15M315
11 Cylinder, motor 1 Not sold separately. See Replacement Air Motor
Part Number (Models), page 3.
12 Screw, ground 1 116343 116343
13‡ Cover, upper 1 15M665 15M398
14* Gasket, manifold 2 Not sold separately. See Air Motor Seal Kits, page
18 or Manifold Assembly (Ref. 15, this table)
15 Manifold, assembly, includes Refs. 14, 16,
and 18 (qty. 4)
1 16G521 16G521
16*Gasket, air valve 1 Not sold separately. See Air Motor Seal Kits, page
18 or Manifold Assembly (Ref. 15, this table)
17 Valve, air, assembly; includes Refs. 16 and 18
(qty. 4)
1 24A352 24X156
18 Screw, M6 x 25 8 Not sold separately. See Manifold Assembly (Ref. 15,
this table) or Air Valve Assembly (Ref. 17, this table)
19 Valve, pilot 2 24A366 24A366
28 Bumper Kit
Lower bumper only
Lower bumper, upper bumper, and screws
(qty. 3)
1
24A914
24A915
29 Bumper, upper 1 Not sold separately. See
Bumper Kit (Ref. 28, this
table)
30 Screw, M5, flat head 3
31 Ring, lift 1 16A795 16A795
32 O-ring, for adapter 1 110782 110782
33* Seal, u-cup with flange 1 Not sold separately. See Air Motor Seal Kits, page
18 or Lower Cover Assembly (Ref. 1, this table)

Kits
18 Manual 3A7718A
Kits
Air Motor Seal Kits Air Valve Parts
Air Motor Model Air Motor Seal Kit
26A938 24A551
26A939 24A547
Apply lubricant.
1
110
110
106†
1
106†
1
107
107
108†
1
108†
1
102
109†
105
112
1
111
103104
101

Kits
Manual 3A7718A 19
Air Valve Kits
NOTE: Air valve parts are not sold individually. The table below shows possible kit options for each part.
† Included in Air Valve Seal Kit 24A536.
Included in Air Valve Repair Kit 24A538.
Included in Air Valve End Cap Kit 24A361.
Ref. Description Qty.
Air Valve
Repair Kit
24A538
Air Valve
Seal Kit
24A536
Air Valve
End Cap Kit
24A361 Other
101 HOUSING 1
102AIR VALVE PISTON 1
103DETENT PISTON
ASSEMBLY
1
104DETENT CAM 1
105PLATE, air valve 1
106† O-RING 2 
107CAP 2
108†U-CUP 2
109†SCREW 2 Screws Kit 24A359
(pack of 10)
110 SNAP RING 2
111DETENT SPRING 1
112CUP 1
18 SCREW, M6 x 25 4 See Manifold Assembly (Ref. 15,
Air Motor Kit Parts table) or
Air Valve Assembly (Ref. 17, Air
Motor Kit Parts table)
16*†AIR VALVE GASKET 1 See Air Motor Seal Kit (page 18)
or
Manifold Assembly (Ref. 15, Air
Motor Kit Parts table) or
Air Valve Assembly (Ref. 17, Air
Motor Kit Parts table)

Dimensions
20 Manual 3A7718A
Dimensions
t in
Air Motor
Model
A
inch (mm)
B
inch (mm)
C
inch (mm)
Weight
lb (kg)
26A939 11.7 (297) 11.4 (290) 8.5 (216) 23.0 (10.4)
26A938 11.7 (297) 12.9 (328) 10.0 (254) 29.0 (13.1)