Graco GX-16 User manual

313536U
EN
Instructions - Parts
GX-16
For dispensing polyol and isocyanate materials only. For professional use only.
For indoor use only. Not approved for use in European explosive atmosphere
requirements.
3000 psi (21 MPa, 207 bar) Maximum Fluid Working Pressure
2500 psi (17 MPa, 172 bar) Maximum Hydraulic Working Pressure
180°F (82°C) Maximum Fluid Temperature
Important Safety Instructions
Read all warnings and instructions in this
manual. Save these instructions.
ti12896a
Model 257496 shown

2313536U
Contents
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Important Two-Component Material Information . 6
Isocyanate Conditions . . . . . . . . . . . . . . . . . . . . . 6
For all applications except spray foam . . . . . . . . 7
Material Self-ignition . . . . . . . . . . . . . . . . . . . . . . 7
Keep Components A and B Separate . . . . . . . . . 7
Moisture Sensitivity of Isocyanates . . . . . . . . . . . 7
Foam Resins with 245 fa Blowing Agents . . . . . . 8
Changing Materials . . . . . . . . . . . . . . . . . . . . . . . 8
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Trigger Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Gun Connections . . . . . . . . . . . . . . . . . . . . . . . 10
Fluid Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Gun Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Shutoff Valve Setup . . . . . . . . . . . . . . . . . . . . . 12
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Theory of Operation . . . . . . . . . . . . . . . . . . . . . 14
Pressure Relief Procedure . . . . . . . . . . . . . . . . . . 15
Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Recommended Tools . . . . . . . . . . . . . . . . . . . . 16
Grease the Gun . . . . . . . . . . . . . . . . . . . . . . . . 16
Recommended Hydraulic Oil . . . . . . . . . . . . . . 16
Recommended Grease . . . . . . . . . . . . . . . . . . . 16
Clean and Service the Orifices and Filters . . . . 17
Proximity Switch Replacement Procedure . . . . 18
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Gun Models 257496, 257498, 257499,
257505, 257506, 257507, 24J187, 24E876 20
Gun Models 257492, 257493, 257494, 257495 22
Gun Models 257497, 257502, 257503, 257504,
24E877, 24E878 . . . . . . . . . . . . . . . . . . . . . 24
Gun Models 24K233, 24K234 . . . . . . . . . . . . . . 26
Dispenser Models 257513, 257514, 257515 . . 28
Gun Models 26C466, 25E973, 25E974, 25E975 30
Orifices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Gun Handle Kit 24K223 . . . . . . . . . . . . . . . . . . 33
Gun Handle Models 257509, 257510 . . . . . . . 34
Gun Handle Model 26C463 . . . . . . . . . . . . . . . 35
Pour Handle Models 257594, 257596 . . . . . . . . 37
Optional Shutoff Valve Kit . . . . . . . . . . . . . . . . . 38
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
California Proposition 65 . . . . . . . . . . . . . . . . . . . 41
Graco Standard Warranty . . . . . . . . . . . . . . . . . . . 42
Graco Information . . . . . . . . . . . . . . . . . . . . . . . . . 42

Models
313536U 3
Models
Models used specifically for HFR machines.
Models used specifically for HFR-NVH machines.
† Models are CE approved.
Part No. Description
257492† GX-16 Pour Gun, 24:1, Pour Handle, Right Side Chemical Tubes,
Star-Shaped Trigger Switch Connector
257493† GX-16 Pour Gun, 24:1, Pour Handle, Left Side Chemical Tubes,
Star-Shaped Trigger Switch Connector
257494† GX-16 Pour Gun, 24:1, Pour Handle, Right Side Chemical Tubes, Cir-
cular Trigger Switch Connector
257495† GX-16 Pour Gun, 24:1, Pour Handle, Left Side Chemical Tubes, Cir-
cular Trigger Switch Connector
257496† GX-16 Pour Gun, 24:1, Isolated Pistol Handle
257497† GX-16 Pour Gun, 24:1, No Handle
257498† GX-16 Pour Gun, No Handle, No Orifice
257499† GX-16 Pour Gun, Reverse Block, No Handle, No Orifice
257502† GX-16 Pour Gun, 1:1, No Handle
257503† GX-16 Pour Gun, 1:1, No Handle, No Fittings
257504† GX-16 Pour Gun, 1:1, No Handle, 3 ft Hoses
257505† GX-16 Pour Gun, 1:1, Pistol Handle, No Orifice, Proximity Switch
257506† GX-16 Pour Gun, 1:1, Isolated Pistol Handle, Proximity Switch
257507† GX-16 Pour Gun, 1:1, Isolated Pistol Handle, No Orifice, Proximity
Switch
24E876†GX-16 Pour Gun, HFR™, NVH, Straight, Basic
24E877† GX-16 Pour Gun, HFR, NVH, Right, 24:1
24E878† GX-16 Pour Gun, HFR, NVH, Right, Basic
24J187† GX-16 Pour Gun, HFR, NVH, Straight, 24:1
24K233† GX-16 Pour Gun, HFR, NVH, Left, 24:1
24K234† GX-16 Pour Gun, HFR, NVH. Left, Basic
25E973GX-16 Pour Gun, No Handle, 1:1, PEEK Nozzle
25E974GX-16 Pour Gun, No Handle, 24:1, PEEK Nozzle
25E975GX-16 Pour Gun, LED Handle, 1:1, Magnetic Nozzle
26C466GX-16 Pour Gun, LED Handle, 24:1, Magnetic Nozzle
25R248GX-16 Pour Gun, LED Handle, 24:1, Plain Nozzle
25P155GX-16 Pour Gun, No Handle, 2:1, Plain Nozzle
25P154GX-16 Pour Gun, LED Handle, 2:1, Plain Nozzle
25R249GX-16 Pour Gun, LED Handle, 1:1, Plain Nozzle

Warnings
4313536U
Warnings
The following warnings are for the setup, use, grounding, maintenance, and repair of this equipment. The exclama-
tion point symbol alerts you to a general warning and the hazard symbol refers to procedure-specific risk. Refer back
to these warnings. Additional, product-specific warnings may be found throughout the body of this manual where
applicable.
WARNING
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 Sheet (SDS) for handling instructions and to know the specific hazards of the
fluids you are using, including the effects of long-term exposure.
• When spraying, servicing equipment, or when in the work area, always keep work area well
ventilated and always wear appropriate personal protective equipment. See Personal Protective
Equipment warnings in this manual.
• Store hazardous fluid in approved containers, and dispose of it according to applicable guidelines.
PERSONAL PROTECTIVE EQUIPMENT
Always wear appropriate personal protective equipment and cover all skin when spraying, servicing
equipment, or when in the work area. Protective equipment helps prevent serious injury, including
long-term exposure; inhalation of toxic fumes, mists or vapors; allergic reaction; burns; eye injury and
hearing loss. This protective equipment includes but is not limited to:
• A properly fitting respirator, which may include a supplied-air respirator, chemically impermeable
gloves, protective clothing and foot coverings as recommended by the fluid manufacturer and local
regulatory authority.
• Protective eyewear and hearing protection.
SKIN INJECTION HAZARD
High-pressure fluid from dispensing device, 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.
• Engage trigger lock when not dispensing.
• Do not point dispensing device at anyone or at any part of the body.
• Do not put your hand over the fluid outlet.
• Do not stop or deflect leaks with your hand, body, glove, or rag.
• Follow the Pressure Relief Procedure when you stop dispensing 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

Warnings
313536U 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 Data in all equipment manuals.
•Use fluids and solvents that are compatible with equipment wetted parts. See Technical Data in all equip-
ment manuals. Read fluid and solvent manufacturer’s warnings. For complete information about your material,
request MSDS 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.
•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.
FIRE AND EXPLOSION HAZARD
Flammable fumes, such as solvent and paint fumes, in work area can ignite or explode. 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 arc).
•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 pres-
ent.
•Ground all equipment in the work area. See Grounding instructions.
•Use only grounded hoses.
•Hold gun firmly to side of grounded pail when triggering into pail.
•If there is static sparking or you feel a shock, stop operation immediately. Do not use equipment until you
identify and correct the problem.
•Keep a working fire extinguisher in the work area.
BURN HAZARD
Equipment surfaces and fluid that’s heated can become very hot during operation. To avoid severe burns:
•Do not touch hot fluid or equipment.
PRESSURIZED ALUMINUM PARTS HAZARD
Use of fluids that are incompatible with aluminum in pressurized equipment can cause serious chemical reaction
and equipment rupture. Failure to follow this warning can result in death, serious injury, or property damage.
•Do not use 1,1,1-trichloroethane, methylene chloride, other halogenated hydrocarbon solvents or fluids con-
taining such solvents.
•Many other fluids may contain chemicals that can react with aluminum. Contact your material supplier for
compatibility.
WARNING

Important Two-Component Material Information
6313536U
Important Two-Component Material Information
Isocyanate Conditions
Spraying or dispensing fluids that contain isocyanates creates potentially harmful mists, vapors, and atomized
particulates.
• Read and understand the fluid manufacturer’s warnings and Safety Data Sheet (SDS) to know specific haz-
ards and precautions related to isocyanates.
• Use of isocyanates involves potentially hazardous procedures. Do not spray with this equipment unless you
are trained, qualified, and have read and understood the information in this manual and in the fluid manu-
facturer’s application instructions and SDS.
• Use of incorrectly maintained or mis-adjusted equipment may result in improperly cured material.which
could cause off gassing and offensive odors. Equipment must be carefully maintained and adjusted accord-
ing to instructions in the manual.
• To prevent inhalation of isocyanate mists, vapors and atomized particulates, everyone in the work area
must wear appropriate respiratory protection. Always wear a properly fitting respirator, which may include
a supplied-air respirator. Ventilate the work area according to instructions in the fluid manufacturer’s SDS.
• Avoid all skin contact with isocyanates. Everyone in the work area must wear chemically impermeable
gloves, protective clothing and foot coverings as recommended by the fluid manufacturer and local regu-
latory authority. Follow all fluid manufacturer recommendations, including those regarding handling of con-
taminated clothing. After spraying, wash hands and face before eating or drinking.
• Hazard from exposure to isocyanates continues after spraying. Anyone without appropriate personal pro-
tective equipment must stay out of the work area during application and after application for the time period
specified by the fluid manufacturer. Generally this time period is at least 24 hours.
• Warn others who may enter work area of hazard from exposure to isocyanates. Follow the recommenda-
tions of the fluid manufacturer and local regulatory authority. Posting a placard such as the following outside
the work area is recommended:
TOXIC FUMES
HAZARD
DO NOT ENTER DURING
SPRAY FOAM APPLICATION
OR FOR ___ HOURS AFTER
APPLICATION IS COMPLETE
DO NOT ENTER UNTIL:
DATE:
TIME:
____________
____________

Important Two-Component Material Information
313536U 7
For all applications except spray
foam
Material Self-ignition
Keep Components A and B
Separate
Moisture Sensitivity of
Isocyanates
Exposure to moisture (such as humidity) will cause ISO to par-
tially cure, forming small, hard, abrasive crystal that become
suspended in the fluid. Eventually a film will form on the sur-
face and the ISO will begin to gel, increasing in viscosity.
NOTE: The amount of film formation and rate of crystallization
varies depending on the blend of ISO, the humidity, and the
temperature.
Spraying or dispensing fluids that contain isocyanates cre-
ates potentially harmful mists, vapors, and atomized partic-
ulates.
•Read and understand the fluid manufacturer’s warn-
ings and Safety Data Sheet (SDS) to know specific
hazards and precautions related to isocyanates.
•Use of isocyanates involves potentially hazardous pro-
cedures. Do not spray with this equipment unless you
are trained, qualified, and have read and understood
the information in this manual and in the fluid manufac-
turer’s application instructions and SDS.
•Use of incorrectly maintained or mis-adjusted equip-
ment may result in improperly cured material. Equip-
ment must be carefully maintained and adjusted
according to instructions in the manual.
•To prevent inhalation of isocyanate mists, vapors, and
atomized particulates, everyone in the work area must
wear appropriate respiratory protection. Always wear a
properly fitting respirator, which may include a sup-
plied-air respirator. Ventilate the work area according
to instructions in the fluid manufacturer’s SDS.
•Avoid all skin contact with isocyanates. Everyone in
the work area must wear chemically impermeable
gloves, protective clothing and foot coverings as rec-
ommended by the fluid manufacturer and local regula-
tory authority. Follow all fluid manufacturer
recommendations, including those regarding handling
of contaminated clothing. After spraying, wash hands
and face before eating or drinking.
Some materials may become self-igniting if applied too
thick. Read material manufacturer’s warnings and Safety
Data Sheet (SDS).
Cross-contamination can result in cured material in fluid
lines which could cause serious injury or damage equip-
ment. To prevent cross-contamination:
•Never interchange component A and component B
wetted parts.
•Never use solvent on one side if it has been contami-
nated from the other side.
NOTICE
Partially cured ISO will reduce performance and the life of all
wetted parts.
•Always use a sealed container with a desiccant dryer in
the vent, or a nitrogen atmosphere. Never store ISO in
an open container.
•Keep the ISO pump wet cup or reservoir (if installed)
filled with appropriate lubricant. The lubricant creates a
barrier between the ISO and the atmosphere.
•Use only moisture-proof hoses compatible with ISO.
•Never use reclaimed solvents, which may contain mois-
ture. Always keep solvent containers closed when not in
use.
•Always lubricate threaded parts with an appropriate
lubricant when reassembling.

Grounding
8313536U
Foam Resins with 245 fa
Blowing Agents
Some foam blowing agents will froth at temperatures above
90°F (33°C) when not under pressure, especially if agitated.
To reduce frothing, minimize preheating in a circulation sys-
tem.
Changing Materials
Grounding
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.
Pump: use ground wire and clamp (supplied). Connect
ground clamp to a true earth ground.
Gun: ground through connection to a properly grounded
fluid hose and pump.
Fluid supply container: follow local code.
Solvent pails used when flushing: follow local code.
Use only conductive metal pails, placed on a grounded
surface. Do not place the pail on a non-conductive sur-
face, such as paper or cardboard, which interrupts
grounding continuity.
Maintain grounding continuity: When flushing or
relieving pressure, hold metal part of the gun firmly to
the side of a grounded metal pail, then trigger the gun.
NOTICE
Changing the material types used in your equipment
requires special attention to avoid equipment damage
and downtime.
• When changing materials, flush the equipment
multiple times to ensure it is thoroughly clean.
• Always clean the fluid inlet strainers after flushing.
• Check with your material manufacturer for chemi-
cal compatibility.
• When changing between epoxies and urethanes
or polyureas, disassemble and clean all fluid com-
ponents and change hoses. Epoxies often have
amines on the B (hardener) side. Polyureas often
have amines on the B (resin) side.

Trigger Lock
313536U 9
Trigger Lock
Verify that the trigger lock is engaged whenever you stop pouring to avoid accidental triggering. Check daily for
chemical build-up on trigger, trigger lock, and trigger lock spring that can prevent proper trigger lock function.
Engage
To engage the trigger lock, release the trigger. The trig-
ger lock is spring loaded and automatically engages
when the gun trigger is released.
To engage the trigger lock, press the trigger lock down.
Disengage
To disengage the trigger lock, press trigger lock down.
See the following figure.
To disengage the trigger lock, press the trigger lock up.
FIG. 1: Models 257509, 257510
Trigger Lock
ti14491a1
FIG. 2: Kit 24K223
ti10442a
FIG. 3: Models 257509, 257510
ti12896a1
ti14491a1
FIG. 4: Kit 24K223
ti10441a

Setup
10 313536U
Setup
Gun Connections
† Only hoses are taped, fittings are not taped.
FIG. 5
A
B
D
G
C
E
F
ti12897a
Ref Description Tape Color † Fitting Size HFR Systems Only
AA Pressure Line Red 7/16 ORG x
#6 JIC Female
7/16 ORG x
#5 JIC Female
BA Return Line Red and White 7/16 ORG x
#6 JIC Male
7/16 ORG x
#5 JIC Male
CB Pressure Line Blue 7/16 ORG x
#5 JIC Female
7/16 ORG x
#6 JIC Female
DB Return Line Blue and White 7/16 ORG x
#5 JIC Male
7/16 ORG x
#6 JIC Male
EHydraulic Open Line Green and White 7/16 ORG x
#4 JIC Male Extension
7/16 ORG x
#4 JIC Male Extension
FHydraulic Close Line Green 7/16 ORG x
#4 JIC Male Elbow
7/16 ORG x
#4 JIC Male Elbow
GProximity Switch or Plug
(depending on model) NA NA NA

Setup
313536U 11
Fluid Line
Fluid Filter: Use a 25 micron stainless steel element to
filter particles from the fluid as it leaves the pump.
Fluid Drain Valve: Required in your system, to relieve
fluid pressure in the hose and gun.
Gun Setup
1. Verify hydraulic power pack is off.
2. Install hydraulic hoses to power pack.
3. Use a 7/16 in. JIC male-male adapter at the gun end
to connect hoses together. This creates a hydraulic
fluid circulation loop.
4. Turn on the power pack. Circulate oil for 10 minutes
to purge air from hydraulic hoses.
NOTE: Pressure should not increase while air is purged
from hoses.
5. Turn off power pack. Verify no pressure exists in
hoses.
6. Remove the 7/16 in. JIC male-male adapter con-
necting the hydraulic hoses.
7. Attach hydraulic hoses to the gun.
8. Set power pack to manual mode.
9. Attach trigger switch cable and proximity switch
cable (if applicable) to gun and power pack.
10. Verify power pack pressure is 1800 - 2500 psi.
Adjust pressure as required.
Trapped air can cause the pump to cycle unexpectedly,
which could result in serious injury from splashing or
moving parts.
Customer supplied hydraulic hoses must be at least
1/4 in. inner diameter and rated to at least 2500 maxi-
mum working pressure.
FIG. 6
ti14495a
FIG. 7
FIG. 8
ti14496a
ti14497a

Setup
12 313536U
11. Install chemical hoses to gun. See FIG. 5 on page
10 and FIG. 9.
Shutoff Valve Setup
The shutoff valves are used to control chemical flow.
1. Perform pressure relief procedure. See Pressure
Relief Procedure on page 15.
2. Use four chemical hoses to connect shutoff valves
to gun. See FIG. 10.
3. Perform gun setup procedure to connect remaining
hoses. See Gun Setup on page 11.
4. Perform Startup procedure on page 13.
Mounting
Use the following mounting dimensions to mount the
GX-16 gun body.
FIG. 9
FIG. 10: Shutoff Valve Setup
ti18184a
ti18185a
FIG. 11: Mounting Hole Dimensions
FIG. 12: Mounting Block Dimensions
A
Bti14493a
A Width: 1.125 in. (28.58 mm)
B Diameter: 0.159 in. (4.04 mm),
10/32 UNF Thread on one side
C From edge: 0.188 in. (4.78 mm)
D From edge: 0.218 in. (5.54 mm)
D
C
A Width: 0.578 in. (14.7 mm)
B Height: 0.440 in. (11.2 mm)
A
B
ti14492a

Startup
313536U 13
Startup
1. If your setup uses the optional shutoff valves,
rotate the handles to the “open” position.
2. Verify cables and hoses are correctly setup. See
Gun Connections section on page 10.
3. Check for excessive wear on cables and hoses.
Replace as necessary.
4. Close dump valve on hydraulic power pack.
5. Start power pack and verify hydraulic pressure is
1800 - 2500 psi.
6. Start chemical pumps.
7. Verify chemical pressure is in desired range.
8. Dispense a test shot into a waste container.
9. Clean any residual material from the tip of the gun.
FIG. 13: Shutoff Valves Positions
Open Position Closed Position
ti18186a
Hydraulic pressure must not exceed the maximum
working pressure of 2500 psi (17 MPa, 172 bar).
Chemical pressure must not exceed the maximum
working pressure of 3000 psi (21 MPa, 207 bar).

Operation
14 313536U
Operation
Theory of Operation
Circulation
Hydraulic pressure extends the piston rod to the circula-
tion position. Material enters the material pressure line
and is sent to the material return line.
When the piston rod is extended to this position, it
removes gelled material from the nose assembly.
Dispense
Hydraulic pressure retracts the piston rod to the dis-
pense position. Material enters the A and B material
pressure lines and mixes in the mixing chamber.
When the piston rod is in this position, it blocks material
flow from entering the material return line.
FIG. 14: Circulation
Key:
A A Pressure Line
B A Return Line
C B Return Line
D B Pressure Line
E Hydraulic Open Line
F Hydraulic Close Line
G Piston Rod
H Hydraulic Piston
FDCBAE
G
H
FIG. 15: Dispense
FDCBAE
Key:
A A Pressure Line
B A Return Line
C B Return Line
D B Pressure Line
E Hydraulic Open Line
F Hydraulic Close Line
G Piston Rod
H Hydraulic Piston
H
G

Pressure Relief Procedure
313536U 15
Pressure Relief
Procedure
1. If your setup uses the optional shutoff valves,
rotate the handles to the “open” position.
2. Shut down chemical pumps.
3. Drain air pressure from the A and B side chemical
tanks.
4. After tank air pressure is at zero, close the A and B
tank outlet valves.
5. Verify pressures read zero on chemical pressure
gauges.
6. Turn off hydraulic power pack.
7. Bleed hydraulic pressure via dump valve on power
pack.
8. Verify pressures read zero on hydraulic pressure
gauges.
Shutdown
1. Perform Pressure Relief Procedure.
2. Perform any required maintenance. See Mainte-
nance on page 16.
3. If system will not be in use for longer than two
weeks, the A and B chemical tanks must have
10 psi of dry air pressure.
4. If the gun will not be used for longer than four
weeks, flush the gun.
NOTICE
Air must be dry. Moist air will react with isocyanate
and cause crystallization resulting in significant
component damage.

Maintenance
16 313536U
Maintenance
Recommended Tools
• 7/16 in. open end wrench
• 3/8 in. open end wrench
• 1/8 in. allen key
• 1/4 in. allen key
• Pin vise 117661
• Drill bit (see etching on orifice for size, drill bit
should be same size as orifice)
• O-Ring Pick
• Small brass brush
• 1/4 in. brass barrel brush
• Small flashlight
• Small solvent pump can
• Cleaning rags
• Chemically impermeable gloves
• Safety glasses
• Small chemical and solvent waste container
• Grease gun
• Grease, part 0553-6
Grease the Gun
1. Perform pressure relief procedure. See Pressure
Relief Procedure on page 15.
2. Use a 1/8 in. allen key to remove the plug.
3. Use a grease gun with the required synthetic
grease, part 0553-6, to purge the gun body until
grease exits the weep hole without evidence of
hydraulic oil or hardened material.
4. Use a 1/8 in. allen key to install the plug.
Recommended Hydraulic Oil
Recommended Grease
Procedure Frequency
Inspect the gun, fluid lines, trigger switch cable and, if
installed, the proximity switch cable for wear or damage
Daily
Grease the gun Weekly or Every
15,000 Shots
Clean and service the orifices and filters As Needed
ti12899a1
FIG. 16: Grease Fitting
NOTICE
Recommended Hydraulic Oil
Use Graco-approved Hydraulic Oil, Part No.
169236 (5 gal) or 207428 (1 gal)) or a premium, ISO
grade 46 petroleum-based hydraulic oil containing
rust and oxidation inhibitors and anti-wear agents.
Before using any other type of oil in this motor, con-
tact your Graco distributor. Unauthorized use of
lesser grade oil or substitutes may void the war-
ranty.
Hydraulic Oil Working Temperature
The maximum hydraulic oil operating temperature is
180 °F (82 °C).
NOTICE
Recommended Grease
Use Graco-approved grease, Part No. 0553-6. This
is a synthetic grease with an operating temperature
up to 450 °F.
ti14494a1

Maintenance
313536U 17
Clean and Service the Orifices
and Filters
NOTE: See Dispenser Models 257513, 257514,
257515 on page 28 for applicable part numbers.
1. Perform pressure relief procedure. See Pressure
Relief Procedure on page 15.
2. If your setup uses the optional shutoff valves,
rotate the handles to the “close” position.
3. Use a 7/16 in. wrench to remove the orifice.
4. Use a 1/8 in. allen key to remove the cleanout plug
next to the orifice.
5. Use a 1/4 in. allen key to remove the filter plug (A).
6. Remove the filter (D).
7. Use a pick to remove any hardened material from
filter.
8. Use solvent to flush residue from this side of the gun
block.
9. Use a pin vise and drill bit to carefully clean the ori-
fice.
10. Remove the orifice o-rings.
11. Use a pick to remove any hardened material from
the orifice body.
12. Flush the orifice body with solvent then dry the ori-
fice.
13. Install new o-rings on the orifice.
14. Install new filter.
15. Replace filter retainer o-ring if needed.
16. Apply grease to filter retainer threads then use a
1/4 in. allen key to install the filter retainer.
17. Apply grease to the o-ring plug threads.
18. Install o-rings then use a 1/8 in. allen key to install
cleanout plug next to the orifice.
19. Apply grease to orifice threads then install the orifice
assembly.
20. Repeat for opposite chemical side of gun.
Cross-contamination can result in cured material in
fluid lines which could cause serious injury or dam-
age equipment. To prevent cross-contamination of
the equipment’s wetted parts, never interchange
component A (isocyanate) and component B (resin)
parts.
FIG. 17:
Key:
A Filter Plug
B Filter Plug O-Ring
C Filter O-Ring
D Filter
E Orifice O-Rings
FOrifice
G Grease Port Plug
H Cleanout Plug
J Cleanout Plug O-Ring
KPlug
L Plug O-Ring
A
B
C
D
E
F
G
J
H
B Side
A Side
K
ti12899a
L
H

Maintenance
18 313536U
Proximity Switch Replacement
Procedure
1. Perform pressure relief procedure. See Pressure
Relief Procedure on page 15.
2. Remove proximity switch cable attached to proxim-
ity switch.
3. Remove proximity switch from rear of gun body.
4. Install new proximity switch.
5. Attach proximity switch cable to proximity switch.
FIG. 18
ti12897a

Troubleshooting
313536U 19
Troubleshooting
Problem Cause Solution
Poor mixing One or both sides of gun are clogged Clean the gun, see Maintenance on
page 16
One or both orifices may need to be
replaced
Hydraulic piston not opening fast
enough due to insufficient hydraulic
pressure
Verify hydraulic unit pressure and
accumulator charge
No fluid being dispensed Insufficient pressure to move hydrau-
lic piston to the dispense position
Verify hydraulic unit pressure and
accumulator charge
Faulty proximity switch Replace proximity switch
Damaged piston u-cup seals Send gun to Graco for repair
Chemical crossover Seal failure on piston rod Send gun to Graco for repair
Hydraulic leak into divorce chamber
(hydraulic fluid found in purged
grease when greasing the gun)
Damaged seal u-cup Send gun to Graco for repair
Proximity switch not working Damaged proximity switch Remove and test the switch, replace
as needed
Damaged proximity switch cord Remove and test the cord, replace as
needed
Valve opens on power up Air in hydraulic lines Disconnect hydraulic hoses from
gun. Follow Gun Setup on page 11.

Parts
20 313536U
Parts
Gun Models 257496, 257498, 257499,
257505, 257506, 257507, 24J187, 24E876
110 112 111
107
109
108
115
104
103
102
104
113
104
105
106
116
117
118
114
101
101a, c 101b, d
105
104
Model 257496 shown
ti12900a
Ref. Part Description
Quantity by Model
257496 257498 257499 257505 257506 257507 24J187 24E876
101
257513
DISPENSER, GX-16, 1:1,
pre-assy 1 1 1
257514
DISPENSER, GX-16, 24:1,
pre-assy 1 1 1 1
257515
DISPENSER, GX-16, rev
block, pre-assy 1
. 101a. 122685
. PLUG, sae02, socket head,
m, ms, 6k 1 1 1 2 2 2
. 101b. 261500
. O-RING, #902, fluoroelasto-
mer 1 1 1 2 2 2
. 101c. 122687 . PLUG, sae02, 316 ss 111