Graco Merkur ES User manual

3A0732U
EN
Instructions/Parts
Merkur® ES Spray
Packages
For low-volume fine finish spray applications. For professional use only.
15:1 Spray Packages
30:1 Spray Packages
100 psi (0.7 MPa, 7.0 bar) Maximum Air Inlet Pressure
See page 3 for model information, including maximum fluid
working pressure.
Important Safety Instructions
Read all warnings and instructions in
this manual. Save these instructions.
ti15590a
ti15589a
II 2 G Ex h T5 Gb X

2 3A0732U
Contents
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Prepare the Operator . . . . . . . . . . . . . . . . . . . . . . 7
Prepare the Site . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Supplied Components . . . . . . . . . . . . . . . . . . . . . 7
Inline Fluid Filter Kits . . . . . . . . . . . . . . . . . . . . . . 7
Air Line Accessories . . . . . . . . . . . . . . . . . . . . . . 7
Wall Mount Packages . . . . . . . . . . . . . . . . . . . . . 8
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Flush Before Using Equipment . . . . . . . . . . . . . . 8
Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Pressure Relief Procedure . . . . . . . . . . . . . . . . . 10
Trigger Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Prime the Pump . . . . . . . . . . . . . . . . . . . . . . . . . 10
Install the Spray Tip . . . . . . . . . . . . . . . . . . . . . . 11
Adjust the Atomization. . . . . . . . . . . . . . . . . . . . 11
Adjust the Spray Pattern . . . . . . . . . . . . . . . . . . 12
Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Tighten Threaded Connections . . . . . . . . . . . . . 13
Flush the Pump . . . . . . . . . . . . . . . . . . . . . . . . . 13
Wet Cup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
General Information . . . . . . . . . . . . . . . . . . . . . . 16
To Remove Intake Valve Only. . . . . . . . . . . . . . . 16
Disconnect the Displacement Pump . . . . . . . . . 16
Disassemble the Pump . . . . . . . . . . . . . . . . . . . 17
Reconnect the Displacement Pump. . . . . . . . . . 19
Repair Air Valve . . . . . . . . . . . . . . . . . . . . . . . . . 19
Replace Pilot Valves. . . . . . . . . . . . . . . . . . . . . . 22
Disconnect the Air Motor . . . . . . . . . . . . . . . . . . 23
Reconnect the Air Motor . . . . . . . . . . . . . . . . . . 23
Repair Air Motor . . . . . . . . . . . . . . . . . . . . . . . . . 24
Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Package Parts . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Hose and Gun . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Air Motor Parts . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Air Valve Parts . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Air Control Parts . . . . . . . . . . . . . . . . . . . . . . . . . 40
Kits and Accessories . . . . . . . . . . . . . . . . . . . . . . . 42
Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . 43
Package Weights . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Wall Bracket Mounting Hole Diagram. . . . . . . . . . 45
Technical Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Performance Charts . . . . . . . . . . . . . . . . . . . . . . . . 47
15:1 Ratio Pumps. . . . . . . . . . . . . . . . . . . . . . . . 47
30:1 Ratio Pumps. . . . . . . . . . . . . . . . . . . . . . . . 48
California Proposition 65 . . . . . . . . . . . . . . . . . . . . 49
Graco Standard Warranty. . . . . . . . . . . . . . . . . . . . 50
Graco Information. . . . . . . . . . . . . . . . . . . . . . . . . . 50

Models
3A0732U 3
Models
Package Series Ratio
Maximum Fluid
Working Pressure
psi (MPa, bar)
Package Type Gun Mounting Material
24F150 B 15:1 1500 (10.3, 103) Air-assisted PerformAA 15 Wall Plated Steel
24F151 B 15:1 1500 (10.3, 103) Air-assisted PerformAA 15 Stand Plated Steel
24F152 B 30:1 3000 (20.7, 207) Air-assisted PerformAA 50 Wall Stainless Steel
24F153 B 30:1 3000 (20.7, 207) Air-assisted PerformAA 50 Stand Stainless Steel
24F154 B 30:1 3000 (20.7, 207) Airless PerformAA 50 Airless Wall Plated Steel
24F155 B 30:1 3000 (20.7, 207) Airless PerformAA 50 Airless Stand Plated Steel
24F156 B 30:1 3000 (20.7, 207) Air-assisted PerformAA 50 Wall Plated Steel
24F157 B 30:1 3000 (20.7, 207) Air-assisted PerformAA 50 Stand Plated Steel
24F158 B 15:1 1500 (10.3, 103) Air-assisted PerformAA 15 Wall Stainless Steel
24F159 B 15:1 1500 (10.3, 103) Air-assisted PerformAA 15 Stand Stainless Steel
24N548* A 30:1 3000 (20.7, 207) WB3000 ----- ----- Stainless Steel
24W281 B 15:1 1500 (10.3, 103) Air-assisted PerformAA 15 Stand Plated Steel
24W283 B 15:1 1500 (10.3, 103) Air-assisted PerformAA 15 Stand Stainless Steel
24W285 B 30:1 3000 (20.7, 207) Air-assisted PerformAA 50 Stand Plated Steel
24W287 B 30:1 3000 (20.7, 207) Air-assisted PerformAA 50 Stand Stainless Steel
24X311** A 15:1 1500 (10.3, 103) Air-assisted ----- Wall Plated Steel
24J250 A 15:1 1500 (10.3, 103) Air-assisted PerformAA 15 WL Wall Plated Steel,
u-cup
24J251 A 15:1 1500 (10.3, 103) Air-assisted PerformAA 15 WL Stand Plated Steel,
u-cup
* Part No. 24N548 is used as a supply pump in the WB3000 Waterborne Isolation System. It includes a pump
bracket and items 7-19, 21, 23, and 28-42 on page 27. See manual 3A2497 for warnings and instructions for a
waterborne system.
** Part No. 24X311 is used as a solvent flush pump in the M2K system. See manual 333309 for warnings and
instructions for a solvent flush pump.

Warnings
4 3A0732U
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, 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
FIRE AND EXPLOSION HAZARD
Flammable fumes, such as solvent and paint fumes, in work area can ignite or explode. Paint or
solvent flowing through the equipment can cause static sparking. To help prevent fire and explosion:
• Use equipment only in well-ventilated area.
• Eliminate all ignition sources, such as pilot lights, cigarettes, portable electric lamps, and plastic
drop cloths (potential static sparking).
• Ground all equipment in the work area. See Grounding instructions.
• Never spray or flush solvent at high pressure.
• Keep work area free of debris, including solvent, rags and gasoline.
• Do not plug or unplug power cords, or turn power or light switches on or off when flammable fumes
are present.
• Use only grounded hoses.
• Hold gun firmly to side of grounded pail when triggering into pail. Do not use pail liners unless they
are anti-static or conductive.
•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.
SPECIAL CONDITIONS FOR SAFE USE
Static charge may build up on plastic parts during cleaning and could discharge and ignite flammable
vapors. To help prevent fire and explosion:
• Clean plastic parts only in well ventilated area.
• Do not clean with a dry cloth.
• Do not operate electrostatic guns in equipment work area.

Warnings
3A0732U 5
SKIN INJECTION HAZARD
High-pressure fluid from gun, hose leaks, or ruptured components will pierce skin. This may look like
just a cut, but it is a serious injury that can result in amputation. Get immediate surgical treatment.
• Do not spray without tip guard and trigger guard installed.
• Engage trigger lock when not spraying.
• Do not point gun at anyone or at any part of the body.
• Do not put your hand over the spray tip.
• Do not stop or deflect leaks with your hand, body, glove, or rag.
• Follow the Pressure Relief Procedure when you stop spraying and before cleaning, checking, or
servicing equipment.
• Tighten all fluid connections before operating the equipment.
• Check hoses and couplings daily. Replace worn or damaged parts immediately.
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 Data in all equipment manuals.
• Use fluids and solvents that are compatible with equipment wetted parts. See Technical Data 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.
• Do not leave the work area while equipment is energized or under pressure.
• 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.
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.
WARNING

Warnings
6 3A0732U
TOXIC FLUID OR FUMES HAZARD
Toxic fluids or fumes can cause serious injury or death if splashed in the eyes or on skin, inhaled, or
swallowed.
• Read Safety Data Sheets (SDSs) to know the specific hazards of the fluids you are using.
• Store hazardous fluid in approved containers, and dispose of it according to applicable guidelines.
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

Installation
3A0732U 7
Installation
Prepare the Operator
All persons who operate the equipment must be trained
in the safe, efficient operation of all system components
as well as the proper handling of all fluids. All operators
must thoroughly read all instruction manuals, tags, and
labels before operating the equipment.
Prepare the Site
Ensure that you have an adequate compressed air
supply.
Bring a compressed air supply line from the air
compressor to the pump location. Be sure all air hoses
are properly sized and pressure-rated for your system.
Use only electrically conductive hoses. The air hose
should have a 3/8 npt(m) thread. A quick disconnect
coupling is recommended.
Keep the site clear of any obstacles or debris that could
interfere with the operator's movement.
Have a grounded, metal pail available for use when
flushing the system.
Supplied Components
See FIG. 2 on page 9.
• The red-handled bleed-type master air valve (D)
is required in your system to relieve air trapped
between it and the air motor and gun when the
valve is closed. Do not block access to the valve.
• The pump air regulator (F) controls pump speed
and outlet pressure by adjusting the air pressure to
the pump.
• The air pressure relief valve (P) opens
automatically to prevent overpressurization of the
pump.
•The gun air regulator (E) adjusts the air pressure
to the air-assisted spray gun.
• The spray gun (H) dispenses the fluid. The gun
houses the spray tip (not shown), which is available
in a wide range of sizes for different spray patterns
and rates of flow. Refer to gun manual for tip
installation.
• The red hose (G) provides the gun air supply.
• The blue hose (K) provides the gun fluid supply.
• The suction kit with strainer (J) allows the pump
to draw fluid from a 5 gallon (19 liter) pail.
Inline Fluid Filter Kits
Inline fluid filter kits are available as an accessory in
stainless steel (24F271) or aluminum (24F272), to filter
particles from fluid as it leaves the pump. Kits include a
60 mesh (250 micron) stainless steel element.
Air Line Accessories
Install the following accessories in the order shown in
FIG. 2, using adapters as necessary.
• An air-line filter (C) removes harmful dirt and
moisture from the compressed air supply.
• A second bleed-type air shutoff valve (B) isolates
the air line accessories for servicing. Locate
upstream from all other air line accessories.

Installation
8 3A0732U
Wall Mount Packages
1. Be sure the wall can support the weight of the
pump, bracket, hoses and accessories, as well as
the stress caused during operation.
2. Position the wall bracket at a convenient height. Do
not stretch the suction hose tight; let it hang to
assist fluid flow into the pump. For ease of
operation and service, make sure the pump air
inlet, fluid inlet, and fluid outlet ports are easily
accessible.
3. Using the wall bracket as a template, drill mounting
holes in the wall. Hole diameters and wall mounting
dimensions are shown on page 45.
4. Attach the bracket to the wall. Use screws that are
long enough to keep the pump from vibrating
during operation.
NOTE: Be sure the bracket is level.
Grounding
1. Pump: See FIG. 1. Verify that the ground wire (26) is
attached to the ground screw (23), and the screw is
tightened securely to the adapter plate (10). Use
any of the three threaded holes in the adapter plate.
Connect the other end of the ground wire to a true
earth ground.
2. Air and fluid hoses: Static electricity may build up
when fluids flow through pumps, hoses, and
sprayers. At least one hose must be electrically
conductive, with a maximum of 500 ft. (150 m)
combined hose length to ensure grounding
continuity. Check electrical resistance of hoses. If
total resistance to ground exceeds 25 megohms,
replace hose immediately.
3. Air compressor: follow manufacturer's
recommendations.
4. Spray gun: ground through connection to a
properly grounded fluid hose and pump.
5. Fluid supply container: follow your local code.
6. Object being sprayed: follow your local code.
7. Solvent pails used when flushing: follow your
local code. Use only metal pails, which are
conductive, placed on a grounded surface. Do not
place the pail on a nonconductive surface, such as
paper or cardboard, which interrupts the grounding
continuity.
8. To maintain grounding continuity when flushing or
relieving pressure, hold a metal part of the spray
gun firmly to the side of a grounded metal pail, then
trigger the gun.
Flush Before Using Equipment
The equipment was tested with lightweight oil, which is
left in the fluid passages to protect parts. To avoid
contaminating your fluid with oil, flush the equipment
with a compatible solvent before using the equipment.
See Prime the Pump, page 10.
The equipment must be grounded. Grounding
reduces the risk of static and electric shock by
providing an escape wire for the electrical current
due to static build up or in the event of a short circuit.
FIG. 1. Ground Wire
23
26
ti16282a
10

Installation
3A0732U 9
Setup
1. See FIG. 2. Attach one end of fluid hose (K) to pump
outlet (or optional inline fluid filter outlet).
2. Attach other end of fluid hose to gun fluid inlet at
base of gun (H).
3. Attach one end of the air hose (G) to gun air
regulator (E).
4. Attach remaining end of the air hose to air inlet at
base of gun (H).
5. Clip fluid and air hoses together with the supplied
hose clips (qty. of 7). Space clips as needed.
6. Attach the fluid suction kit (J) to the pump inlet.
FIG. 2. Typical Installation (Air-Assisted Stand Mount Package Shown)
A
B
C
DF
E
G
N
J
K
L
ti15591a
H
M
P
Key:
A Main Air Supply Line
B Air Shutoff Valve
C Air Filter
D Bleed-type Master Air Valve
(required)
E Gun Air Pressure Regulator
F Pump Air Pressure
Regulator
G Gun Air Supply Line
H Spray Gun
J Fluid Suction Kit
K Gun Fluid Supply Line
L Pump Ground Wire
(required)
M Mounting Bracket (used for
wall mounting or stand)
N Pump Stand
P Air Pressure Relief Valve

Operation
10 3A0732U
Operation
Pressure Relief Procedure
1. Lock the gun trigger.
2. See FIG. 2. Turn off the bleed-type master air valve
(D).
3. Unlock the gun trigger.
4. Hold a metal part of the gun firmly to a grounded
metal waste container. Trigger the gun to relieve
fluid pressure.
5. Lock the gun trigger.
6. If you suspect that pressure has not been fully
relieved after following the steps above, check the
following:
a. The spray tip may be completely clogged. Very
slowly loosen the air cap retaining ring to
relieve pressure in the cavity between the
ball/seat shutoff and the plugged tip. Clear the
tip orifice.
b. The gun fluid filter or the fluid hose may be
completely clogged. Very slowly loosen the
hose end coupling at the gun and relieve
pressure gradually. Then loosen completely to
clear the obstruction.
c. After following the steps above, if the spray tip
or hose still seems completely clogged, very
slowly loosen the tip guard retaining nut or
hose end coupling and relieve pressure
gradually, then loosen completely. With tip
removed, trigger gun into waste container.
Trigger Lock
See FIG. 3. Always engage gun trigger lock when you
stop spraying to prevent gun from being triggered
accidentally by hand or if dropped or bumped.
Prime the Pump
NOTE: Do not let the pump run away or run dry.
1. See FIG. 3. Lock gun trigger. Remove tip guard and
spray tip from gun. Refer to gun manual.
2. See FIG. 2. Close gun air regulator (E) and pump air
regulator (F) by turning knobs counterclockwise
reducing pressure to zero. Close bleed-type air
valve (D).
Trapped air can cause the pump to cycle
unexpectedly, which could result in serious injury
from skin injection, splashing or moving parts.
FIG. 3. Trigger Lock
Have safety spring (9) in place during operation to
reduce risk of pinching or loss of fingers.
tiI6581A
ti6582A
Gun Trigger
Locked
Gun Trigger
Unlocked

Operation
3A0732U 11
3. Connect air line to bleed type air valve.
4. Check that all fittings throughout system are
tightened securely.
5. Position pail close to pump. Suction hose is 3 ft
(0.9 m) long. Do not stretch hose tight; let it hang to
assist fluid flow into pump.
6. Hold metal part of gun firmly to side of grounded
metal pail, unlock trigger, and hold trigger open.
7. Open bleed-type air valve. Slowly turn pump air
regulator clockwise, increasing pressure until pump
starts.
8. Cycle pump slowly until all air is pushed out and
pump and hoses are fully primed.
9. Release gun trigger and lock trigger safety. Pump
should stall against pressure.
Install the Spray Tip
Follow Pressure Relief Procedure, page 10. Install the
spray tip and tip guard as explained in your separate
gun manual, supplied.
The fluid output and pattern width depend on the size
of the spray tip, the fluid viscosity, and the fluid
pressure. Use the Spray Tip Selection Chart in your gun
instruction manual as a guide for selecting an
appropriate spray tip for your application.
NOTE: The maximum recommended spray tip size is
.019 in. (0.483 mm).
Adjust the Atomization
NOTE: Use this procedure with airless and air-assisted
spray guns.
1. Do not turn on atomizing air supply. Fluid pressure
is controlled by the air pressure supplied to the
pump (pump air regulator). Set fluid pressure at low
starting pressure. For low viscosity fluids (less than
25 sec, #2 Zahn cup) with lower percent solids
(typically less than 40%), start at 300 psi (2.1 MPa,
21 bar) at pump outlet. For fluids with higher
viscosity or higher solids content, start at 600 psi
(4.2 MPa, 42 bar). Refer to the following example.
Example:
2. Hold gun perpendicular and approximately 12
inches (304 mm) from surface.
3. Move gun first, then pull gun trigger to spray onto
test paper.
4. Increase fluid pressure in 100 psi (0.7 MPa, 7 bar)
increments, just to the point where a further
increase in fluid pressure does not significantly
improve fluid atomization. Refer to the following
example.
Example:
5. If you are using an air-assisted spray gun, see
Adjust the Spray Pattern on page 12.
Pump
Ratio
Pump Air
Regulator Setting
psi (MPa, bar)
Approximate
Fluid Pressure
psig (MPa, bar)
15:1 x 20 (0.14, 1.4) = 300 (2.1, 21)
30:1 x 20 (0.14, 1.4) = 600 (4.2, 42)
Pump
Ratio
Pump Air Regulator
Increment
psi (MPa, bar)
Incremental
Fluid Pressure
psi (MPa, bar)
15:1 x 7 (.05, 0.5) = 100 (0.7, 7.0)
30:1 x 3.3 (0.02, 0.2) = 100 (0.7, 7.0)

Operation
12 3A0732U
Adjust the Spray Pattern
NOTE: Use this procedure with air-assisted spray guns
only.
1. See FIG. 4. Close off pattern adjustment air by
turning knob (AA) clockwise (in) all the way. This
sets gun for its widest pattern.
2. See FIG. 5. Set atomizing air pressure at about 5 psi
(0.35 bar, 35 kPa) when triggered. Check spray
pattern, then slowly increase air pressure until tails
are completely atomized and pulled into spray
pattern. Do not exceed 100 psi (0.7 MPa, 7 bar) air
pressure to gun.
3. See FIG. 4. For narrower pattern, turn pattern
adjustment valve knob (AA) counterclockwise (out).
If pattern is still not narrow enough, increase air
pressure to gun slightly or use different size tip.
Shutdown
Follow Pressure Relief Procedure, page 10.
Always flush the pump before the fluid dries on the
displacement rod. See Flush the Pump on page 13.
FIG. 4. Pattern Air Knob
ti6559A
OUT (narrower
pattern) IN (wider
pattern)
AA
AA
FIG. 5. Spray Pattern Problems
no air too little air correct
amount of
air TI0792A

Maintenance
3A0732U 13
Maintenance
Tighten Threaded Connections
Before each use, check all hoses for wear or damage.
Replace as necessary. Check that all threaded
connections are tight and leak-free.
Flush the Pump
Flush the pump:
• Before first use
• When changing colors or fluids
• Before repairing equipment
• Before fluid dries or settles out in a dormant pump
(check the pot life of catalyzed fluids)
• At the end of the day
• Before storing the pump.
Flush at the lowest pressure possible. Flush with a fluid
that is compatible with the fluid you are pumping and
with the wetted parts in your system. Check with your
fluid manufacturer or supplier for recommended
flushing fluids and flushing frequency.
1. Follow Pressure Relief Procedure, page 10.
2. Remove tip guard and spray tip from gun. Refer to
separate gun manual.
3. Place suction tube in grounded metal pail
containing cleaning fluid.
4. Set pump to lowest possible fluid pressure, and
start pump.
5. Hold a metal part of the gun firmly to a grounded
metal pail.
6. Trigger gun. Flush system until clear solvent flows
from gun.
7. Follow Pressure Relief Procedure, page 10.
8. Clean the tip guard, spray tip, and fluid filter
element separately, then reinstall them.
9. Clean inside and outside of suction tube and
suction hose.
Wet Cup
Fill wet cup one-half full with Graco Throat Seal Liquid
(TSL). Maintain TSL level daily.
Read all Warnings. Follow all Grounding
instructions. See page 8.

Troubleshooting
14 3A0732U
Troubleshooting
NOTE: Check all possible problems and causes before
disassembling the pump.
Relieve the pressure before checking or servicing
the equipment.
Problem Cause Solution
Air motor will not run. Damaged air valve (214). Replace or service air valve (214).
See page 19.
Damaged pilot valve (213). Replace pilot valves (213). See page
22.
Air continuously exhausting
around air motor piston rod.
Damaged u-cups (207). Replace piston rod u-cups (207).
See page 24.
Air continuously exhausting from
muffler.
Damaged air valve plate (305) or cup
(312).
Replace or service air valve (214).
See page 19.
Air motor “bounces” at top of
stroke.
Damaged bottom pilot valve (213). Replace bottom pilot valve (213).
See page 22.
Air motor “bounces” at bottom of
stroke.
Damaged top pilot valve (213). Replace top pilot valve (213). See
page 22.
Icing inside motor. Air motor operating at high pressure
or high cycle rate.
Reduce pressure, cycle rate, or duty
cycle of motor.
Reduce dew point of compressed
air in moisture coalescing filter.
Pump fails to operate. Restricted line or inadequate air
supply; closed or clogged valves.
Clear line or increase air supply.
Check that the valves are open.
Obstructed fluid hose or gun; fluid
hose ID is too small.
Open, clear*; use hose with larger
ID.
Fluid dried on the displacement rod
(119).
Clean; keep the packing nut
wet-cup filled with Graco throat seal
liquid (TSL).
Pump operates but does not
prime.
Held open or worn ball check valves
or piston packings.
Clear valve; replace packings. See
page 17.
Worn suction hose o-ring (38). Replace suction hose o-ring (38).
Pump operates, but output is low
on both strokes.
Restricted line or inadequate air
supply; closed or clogged valves.
Clear line or increase air supply.
Check that the valves are open.
Obstructed fluid hose or gun; fluid
hose ID is too small.
Open, clear*; use hose with larger
ID.
Worn packings in displacement
pump.
Replace packings. See page 17.

Troubleshooting
3A0732U 15
Pump operates, but output is low
on downstroke.
Held open or worn ball check valves
or piston packings.
Clear valve; replace packings. See
page 17.
Erratic or accelerated pump
speed.
Exhausted fluid supply. Refill and prime.
Held open or worn ball check valves
or packings.
Clear valve, replace packings. See
page 17.
Fluid being pumped is visible in
the packing nut wet-cup.
Worn throat packings. Tighten packing nut.
Replace throat packings. See page
17.
Bad spray pattern. Clean or repair spray gun or tip. See manual 3A8099.
Problem Cause Solution

Repair
16 3A0732U
Repair
General Information
• Reference numbers and letters in parentheses in
the text refer to the callouts in the figures and the
parts drawing.
• Always use Genuine Graco Parts and Accessories,
available from your Graco distributor. If you supply
your own accessories, be sure they are adequately
sized and pressure rated for your system.
To Remove Intake Valve Only
The intake ball and seat may be cleaned or serviced
without disconnecting the displacement pump.
1. Stop the pump.
2. Flush the pump, if possible (see page 13). Follow
Pressure Relief Procedure, page 10.
3. Disconnect the suction hose.
4. Remove the intake housing (110). See FIG. 11.
5. Clean or replace the ball guide (109), ball (116), seat
(117), and o-ring (111).
6. Install the o-ring (111‡), seat (117), intake ball
(116‡), and ball guide (109) in the intake housing
(110).
7. Screw the intake housing (110) onto the cylinder
(105). Torque to 70-80 ft-lb (95-108 N•m).
Disconnect the Displacement
Pump
1. Stop the pump.
2. Flush the pump, if possible (see page 13). Follow
Pressure Relief Procedure, page 10.
3. Disconnect the air hose, fluid hose, and suction
hose.
4. See FIG. 6. Push the safety spring (9) down and
hold to access the coupling pin (18). Push the
retaining spring (19) up and push out the pin, using
a screwdriver or punch.
5. Loosen the jam nut (13).
6. Unscrew the displacement pump by hand and
place on work bench.
FIG. 6. Safety Spring and Connecting Pin
19
9
18
TI16261A
13
10

Repair
3A0732U 17
Disassemble the Pump
NOTE: Pump Repair Kits are available. See page 42.
Parts are marked with an ‡.
1. Follow the instructions under Disconnect the
Displacement Pump, page 16.
2. See FIG. 12. Loosen the packing nut (103), using a
screwdriver and hammer. Remove the o-ring (104).
3. Unscrew the cylinder (105) from the intake housing
(110). The rod and piston assembly will come with
the cylinder.
4. Remove the ball guide (109), intake ball (116), seat
(117), and o-ring (111) from the intake housing
(110).
5. Drive the rod and piston assembly out the bottom
of the cylinder. Remove the o-ring (107) from the
cylinder.
6. Insert a plastic rod in the bottom of the cylinder and
drive the throat packings and glands out the top.
7. Put the rod (119) in a vise and unscrew the piston
(124). Be careful not to drop the piston ball (120).
Disassemble the piston packings from the piston.
8. Clean and inspect all parts. Replace any damaged
parts.
Reassemble the Pump
Assemble the Piston Rod
1. Hold the rod (119) upright in a vice.
2. Place the piston ball (120‡) in the cavity of the rod.
(119).
3. Install piston rod packings.
V-packing models: FIG. 7
NOTE: Soak the leather packings (113‡, 125‡) in
hydraulic oil for one hour before installation.
a. Install the female gland (121‡) onto the rod
(119).
b. Install v-packings in an alternating order onto
the rod (119). Start with blue UHMWPE (126),
and then and leather (125).
c. Install the male gland (122‡) onto the rod.
d. Install the piston wiper (123‡) onto the piston
(124).
U-Cup Models (24J250 and 24J251): FIG. 8
Install the u-cup (129) and the bushing (130) onto the
rod (119).
4. Install the piston (124) into the rod (119). Torque to
24-30 ft-lb (33-40 N•m).
FIG. 7: Piston v-packings
FIG. 8: Piston u-cup packings (models 24J250 and
24J251)
119
125‡
122‡
‡121
120‡
‡126
124
‡123
105
119
130
129
120‡

Repair
18 3A0732U
Install Throat Packings
Install the throat packings in the cylinder (105).
V-Packing Models: FIG. 9
a. Install the male gland (114‡).
b. Install v-packings in an alternating order. Start
with blue UHMWPE (106‡), and then and
leather (113‡). See FIG. 9.
c. Install the female gland (112‡).
U-Cup Models (24J250 and 24J251): FIG. 10
a. Install the u-cup (128) with the lips facing down
and the bushing (127) onto the rod (119).
Install the Piston Rod and Cylinder
1. Install the o-ring (104‡) on the packing nut (103)
(v-packing models only).
2. Loosely install the packing nut (103) in the cylinder
(105).
3. Press the button plug (102‡) onto the packing nut
(103).
4. Liberally lubricate the packings and the top 2 in. (51
mm) of the rod (119).
5. Push the displacement rod (119) into the cylinder
(105) from the bottom until the piston is completely
in the cylinder and the rod protrudes from the
packing nut (103).
6. Grease the o-ring (107‡) and install it on the
cylinder (105).
Assemble the Intake Housing
1. Install the o-ring (111‡), seat (117), intake ball
(116‡), and ball guide (109) in the intake housing
(110).
2. Screw the cylinder (105) and the intake housing
(110) together. Torque to 70-80 ft-lb (95-108 N•m).
3. Tighten the packing nut (103) on the cylinder (105).
Torque to 60-80 in-lb (6.7-9.0 N•m).
FIG. 9: V-packing throat packings
105
113‡ ‡106
‡102
103
‡112
‡114
‡104
15
Lips must face down.
1
1
1
FIG. 10: U-cup throat packings
105
15
‡102
127
103
128
Lips must face down.
1
1

Repair
3A0732U 19
4. Follow the Reconnect the Reconnect the
Displacement Pump, pg 19. Reconnect the Displacement
Pump
1. Screw the displacement pump into the adapter
plate (10) until it stops. Back off pump less than 1
turn, to align pump outlet as desired.Tighten the
jam nut (13). Torque to 65-75 ft-lb (88-102 N•m).
2. Align the hole in the displacement rod with the hole
in the air motor rod. Use a screwdriver to push in
the pin (18).
3. Push the retaining spring (19) into place to cover
the pin.
4. Fill throat packing nut wet-cup (103) with TSL to
prevent premature packing wear.
Repair Air Valve
Replace Complete Air Valve
1. Stop the pump. Follow Pressure Relief
Procedure, page 10.
2. Disconnect the air line to the motor.
3. See FIG. 18 on page 25. Remove four screws (211).
Remove the air valve (214) and gasket (209* ◆ ).
4. To repair the air valve, go to Disassemble the Air
Valve, page 20. To install a replacement air valve,
continue with step 5.
5. Align the new air valve gasket (209* ◆ ) on the
manifold, then attach the air valve (214). Torque
screws (211) to 95-105 in-lb (11-12 N•m).
6. Reconnect the air line to the motor.
Replace Seals or Rebuild Air Valve
FIG. 11: Intake housing assembly
119
117
116‡
110
111‡
109
107‡
105
NOTICE
The displacement pump can be damaged if the
stroke is not centered when the pump is recon-
nected. Be sure to fully screw the displacement
pump into the adapter plate (10).

Repair
20 3A0732U
NOTE: Air Valve Seal Kits are available. See page 39.
Parts are marked with an †.
Air Valve Repair Kits are available. See page 39. Parts
are marked with an ◆ .
Air Valve End Cap Kits are available. See page 39. Parts
are marked with an ✚ .
Disassemble the Air Valve
1. Perform steps 1-3 under Replace Complete Air
Valve, page 19.
2. See FIG. 12. Use a 2 mm or 5/64 hex key to remove
two screws (309† ◆ ). Remove the valve plate
(305 ◆ ), cup (312 ◆ ), and spring (311 ◆ ).
3. See FIG. 13. Remove the snap ring (310
✚ ) from
each end. Use the piston to push the end caps
(307 ✚ ) out of the ends. Remove end cap o-rings
(306† ✚◆ ).
4. Remove the piston (302 ◆ ). Remove the u-cup seals
(308† ◆ ) from each end and the detent assembly
(303 ◆ ) and detent cam (304 ◆ ) from the center.
FIG. 12. Air Plate Removal
309†
305
312 311
ti16284a