GUSMER GAP Pro User manual

GAP Pro
Spray Gun
Operating Manual
36943-1
March 10, 2004
Issue 1
GUSMER CORPORATION ®
A Subsidiary of Gusmer Machinery Group, Inc.
One Gusmer Drive
Lakewood, New Jersey, USA 08701-8055
Toll Free 1-800-367-4767 (USA & Canada)
Phone: [phone]
Fax: [phone]
Copyright 2004, GUSMER CORPORATION ®
http://www.gusmer.com
NOTICE: This manual contains important information for your GUSMER equipment. Read and retain for future reference.

GAP Pro Spray Gun
2 36943-1, Issue 1
NOTICE: The equipment described in this technical manual must only be operated or serviced by properly trained
individuals, thoroughly familiar with the operating instructions and limitations of the equipment. For technical service, call
your local distributor. Call: 1-800-FOR-GSMR (1-800-367-4767) for the name and telephone number of your local
distributor.
NOTICE: All statements, information and data given herein are believed to be accurate and reliable but are presented
without guarantee, warranty or responsibility of any kind expressed or implied. Statements or suggestions concerning
possible use of GUSMER equipment are made without representation or warranty that any such use is free of patent
infringement, and are not recommendations to infringe any patent. The user should not assume that all safety measures are
indicated or that other measures may not be required for a particular circumstance or application.

Operating Manual Contents
3/10/04 3
CONTENTS
LIST OF FIGURES.......................................................................................................... 4
WARRANTY .................................................................................................................... 5
GENERAL SAFETY INFORMATION.........................................................................6
ACCEPTABLE EQUIPMENT USES ......................................................................................6
OPERATIONAL SAFETY PROCEDURES ..............................................................................7
MAJOR COMPONENTS................................................................................................ 8
OPERATION....................................................................................................................9
SAFETY STOP OPERATION ...............................................................................................9
MANUAL VALVE OPERATION ..........................................................................................9
AIR HOSE CONFIGURATIONS .........................................................................................10
INITIAL SET UP PROCEDURE..........................................................................................11
DAILY START UP PROCEDURE.......................................................................................11
DAILY SHUTDOWN PROCEDURE ....................................................................................12
SERVICING PROCEDURES....................................................................................... 13
SIDE BLOCK SERVICE PROCEDURE ................................................................................13
MIXING CHAMBER AND GUN BLOCK SERVICE PROCEDURE ..........................................14
END CAP AND AIR PISTON O-RING SERVICE PROCEDURE .............................................16
END CAP O-RING AND SAFETY STOP CUP SEAL SERVICE PROCEDURE .........................18
TRIGGER VALVE O-RING PROCEDURE ..........................................................................20
AIR PASSAGE DIAGRAMS ........................................................................................23
APPENDIX .....................................................................................................................24
SPECIFICATIONS ............................................................................................................24
INSTRUCTION MANUAL DISCREPANCY REPORT ...........................................25

GAP Pro Spray Gun
4 36943-1, Issue 1
LIST OF FIGURES
FIGURE 1. MAJOR COMPONENTS .......................................................................................8
FIGURE 2. FRONT END COMPONENTS ................................................................................8
FIGURE 3. ENGAGE THE SAFETY STOP................................................................................9
FIGURE 4. DISENGAGE THE SAFETY STOP...........................................................................9
FIGURE 5. MANUAL VALVES...............................................................................................9
FIGURE 6. AIR HOSE CONFIGURATION .............................................................................10
FIGURE 7. SIDE BLOCK COMPONENT REMOVAL / INSTALLATION .......................................13
FIGURE 8. TIGHTNING THE CHECK VALVE RETAINER........................................................14
FIGURE 9. MIXING CHAMBER AND GUN BLOCK REMOVAL/INSTALLATION...........................15
FIGURE 10. END CAP AND PISTON ASSEMBLY....................................................................17
FIGURE 11. PISTON ASSEMBLY..........................................................................................17
FIGURE 12. END CAP ASSEMBLY.......................................................................................19
FIGURE 13. SAFETY STOP ASSEMBLY.................................................................................19
FIGURE 14. TRIGGER/AIR VALVE ASSEMBLY ......................................................................21
FIGURE 15. AIR CYLINDER AIR PASSAGES .........................................................................23
FIGURE 16. HANDLE AIR PASSAGES ..................................................................................23

Operating Manual Warranty
3/10/04 5
WARRANTY
Gusmer Corporation (Gusmer) provides a limited warranty to the original purchaser (Customer) of
Gusmer manufactured parts and equipment (Product) against any defects in material or
workmanship for a period of one year from the date of shipment from Gusmer facilities.
In the event Product is suspected to be defective in material or workmanship, it must be returned to
Gusmer, freight prepaid. If Product is found to be defective in material or workmanship, as
determined solely by Gusmer, Gusmer will issue full credit to Customer for the freight charges
incurred in returning the defective Product, and either credit will be issued for the replacement cost
of the Product or a replacement part will be forwarded no-charge, freight prepaid to Customer.
This warranty shall not apply to Product Gusmer finds to be defective resulting from: installation,
use, maintenance, or procedures not accomplished in accordance with our instructions; normal
wear; accident; negligence; alterations not authorized in writing by Gusmer; use of “look alike”
parts not manufactured or supplied by Gusmer; or Product used in conjunction with any other
manufacturer's pumping or proportioning equipment. For such Product, a written estimate will be
submitted to the Customer at a nominal service charge, itemizing the cost for repair. Disposition of
Product will be done in accordance with the terms stated on the written estimate.
The warranty provisions applied to product that are not manufactured by Gusmer will be solely in
accordance with the warranty provided by the original manufacturer of the product.
GUSMER MAKES NO WARRANTY WHATSOEVER AS TO THE MERCHANTABILITY OF,
OR SUITABILITY FOR, ITS PRODUCT TO PERFORM ANY PARTICULAR PURPOSE.
CREDIT FOR, OR REPLACEMENT OF, PRODUCT DEFECTIVE IN MATERIAL OR
WORKMANSHIP SHALL CONSTITUTE COMPLETE FULFILLMENT OF GUSMER
OBLIGATIONS TO CUSTOMER. NO OTHER WARRANTY, EXPRESS OR IMPLIED ON
ANY PRODUCT IT MANUFACTURES AND/OR SELLS, WILL BE RECOGNIZED BY
GUSMER UNLESS SAID WARRANTY IS IN WRITING AND APPROVED BY AN OFFICER
OF GUSMER.
Under no circumstances shall Gusmer be liable for loss of prospective or speculative profits, or
special indirect, incidental or consequential damages. Further, Gusmer shall have no liability for
any expenses including, but not limited to personal injury or property damage resulting from failure
of performance of the product, use of the product, or application of the material dispensed through
the product. Any information provided by Gusmer that is based on data received from a third
source, or that pertains to product not manufactured by Gusmer, while believed to be accurate and
reliable, is presented without guarantee, warranty, or responsibility of any kind, express or implied.
Gusmer through the sale, lease, or rental of Product in no way expresses or implies a license for the
use of, nor encourages the infringement of any patents or licenses.
To ensure proper validation of your warranty, please complete the warranty card and return it to
Gusmer within two weeks of receipt of equipment.
Revised 09/02

GAP Pro Spray Gun
6 36943-1, Issue 1
GENERAL SAFETY INFORMATION
It is necessary to understand and follow the instructions in this manual to ensure proper
and safe operation of the equipment.
As with most mechanical equipment, certain safety precautions must be taken when the
equipment discussed in this manual is operated or serviced. Severe bodily injury or
damage to equipment and property may result if the instructions and precautions listed
throughout this manual are not followed.
Needless to say, sufficient guidelines cannot be developed to eliminate the need for good
common sense in the use and servicing of this equipment, and in the use and application
of the products, this equipment has been designed to process. Users of this equipment
must therefore, make their own determination as to the suitability of the information
contained in this manual to their specific operation and requirements. There should be
no assumption made that the safety measures and instructions contained herein are all-
inclusive, and that other safety measures may not be required for specific use or
application.
The following safety guidelines are generally applicable to the safe and efficient use of
the equipment.
Acceptable Equipment Uses
The equipment is designed for the dispensing of polyurethane foams, two-component
coating systems such as polyureas, and some two-component epoxy systems. Under no
circumstances should any acid or corrosive chemicals be used in the unit. Consult
GUSMER if there is any doubt about the compatibility of the chemical system to be used
in this equipment.
Any use of this equipment other than as indicated above constitutes misuse unless
express written approval is obtained from GUSMER.
Your Gusmer equipment incorporates design parameters, features, and functionality
developed in over 40 years of plural component equipment design and manufacture. It is
manufactured under the stringent standards of ISO 9001, and is backed by the Gusmer
Warranty included herein.
The use of genuine Gusmer replacement parts is recommended for your equipment.
Substitution of parts not designed, manufactured, or recommended by Gusmer may result
in reduced performance of, and/or damage to, your Gusmer equipment. Any alterations
to, or substitutions for, genuine Gusmer parts shall void the provisions of the Gusmer
Warranty.

Operating Manual General Safety Information
3/10/04 7
Operational Safety Procedures
This safety information will not be repeated in the text of this manual. The symbols
pertaining to this information will appear where appropriate to alert the operator to
potential hazards.
Solvents and Chemicals
WARNING: THE SOLVENTS AND CHEMICALS USED WITH THIS EQUIPMENT EXPOSE THE
OPERATOR TO CERTAIN HAZARDS. ADEQUATE PERSONAL PROTECTIVE MEASURES MUST BE
TAKEN SO AS TO AVOID EXCEEDING THE THRESHOLD LIMIT VALUE (TLV) OF THE PRODUCTS
BEING USED, AS ESTABLISHED BY THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION
(OSHA) OR OTHER QUALIFIED AGENCY. OBTAIN INFORMATION CONCERNING PERSONAL
PROTECTION AND PROPER HANDLING FROM THE SUPPLIER OF SUCH SOLVENTS AND
CHEMICALS.
High Voltage
WARNING: TO PREVENT SERIOUS BODILY INJURY FROM ELECTRICAL SHOCK, NEVER OPEN
THE ELECTRIC CONSOLES OR OTHERWISE SERVICE THIS EQUIPMENT AND/OR EQUIPMENT USED
WITH IT BEFORE SWITCHING OFF THE MAIN POWER DISCONNECT AND SHUTTING OFF AND
LOCKING OUT SUPPLY VOLTAGE AT THE SOURCE. THE ELECTRICAL SERVICE MUST BE
INSTALLED AND MAINTAINED BY A QUALIFIED ELECTRICIAN.
High Pressure
WARNING: THIS EQUIPMENT HAS, OR IS USED WITH EQUIPMENT THAT HAS, HYDRAULIC AND
CHEMICAL COMPONENTS CAPABLE OF PRODUCING UP TO 3500 PSI. TO AVOID SERIOUS
BODILY INJURY FROM EJECTION OF FLUID, NEVER OPEN OR SERVICE ANY CONNECTIONS OR
COMPONENTS WITHOUT BLEEDING ALL PRESSURES TO ZERO.
Personal Protective
Equipment
WARNING: TO AVOID SERIOUS BODILY INJURY, PROPER PROTECTIVE GEAR, APPROPRIATE
FOR THE TASK BEING ACCOMPLISHED, MUST BE WORN WHEN OPERATING, SERVICING, OR BEING
PRESENT IN THE OPERATIONAL ZONE OF THIS EQUIPMENT. THIS INCLUDES, BUT IS NOT
LIMITED TO, EYE AND FACE PROTECTION, GLOVES, SAFETY SHOES, AND RESPIRATORY
EQUIPMENT AS REQUIRED TO PROVIDE PERSONAL PROTECTION FROM SOLVENTS AND
CHEMICALS; HIGH PRESSURE RELEASES; HIGH TEMPERATURES; ELECTRIC SHOCK; AND OTHER
HAZARDS ASSOCIATED WITH HYDRAULIC/ELECTRO-MECHANICAL EQUIPMENT. REFER TO THE
APPROPRIATE WARNINGS ON THIS PAGE FOR FURTHER INFORMATION.
High Temperature
WARNING: THIS EQUIPMENT HAS, OR IS USED WITH EQUIPMENT THAT HAS, HIGH
TEMPERATURE COMPONENTS SUCH AS PRIMARY HEATERS AND HEATED HOSES. TO PREVENT
SERIOUS BODILY INJURY FROM HOT FLUID OR HOT METAL, NEVER ATTEMPT TO SERVICE THE
EQUIPMENT BEFORE ALLOWING IT TO COOL.
Warning
WARNING: FAILURE TO READ AND FOLLOW THE INFORMATION ASSOCIATED WITH THIS
SYMBOL MAY RESULT IN PERSONAL INJURY AND/OR DAMAGE TO THE EQUIPMENT.

GAP Pro Spray Gun
8 36943-1, Issue 1
MAJOR COMPONENTS
In keeping with the need to gain a complete and thorough understanding of the
equipment, please take time to become familiar with the major components of the
GAP Pro (Gusmer Air Purge) Spray Gun and its Front End Components.
Figure 1. Major Components
(Gun shown with Round Spray Tip)
NOTE:
For a detailed account of
the components shown in
Figure 1 and Figure 2,
consult the GAP PRO Spray Gun
Parts Identification Manual
(P/N 36943-ID).
Figure 2. Front End Components
(Gun shown with Flat Spray Tip Assembly)

Operating Manual Operation
3/10/04 9
OPERATION
WARNING: NEVER POINT THE GUN AT OR NEAR OTHER PERSONNEL OR PLACE ANY PART OF
THE BODY IN THE PATH OF THE MATERIAL SPRAY. DO NOT LOOK INTO THE DISPENSING END OF
THE GUN. ALWAYS ENGAGE THE SAFETY STOP AND CLOSE BOTH MANUAL VALVES WHEN NOT
USING THE GUN. DO THIS TO AVOID THE POSSIBILITY OF BODILY INJURY OR PROPERTY
DAMAGE FROM THE ACCIDENTAL OPERATION OF THE GUN.
Safety Stop Operation
The GAP PRO Gun has a two position
Safety Stop. When engaged, it prevents
accidental triggering of the gun during
servicing or down time. When disengaged,
it allows the gun to dispense.
1. TO ENGAGE THE SAFETY
STOP- Push in and turn the Safety
Stop knob clockwise to place the gun
in the Safety detented position. Figure 3. Engage the Safety Stop
IMPORTANT: Always engage the
Safety Stop when the gun is not in use.
2. TO DISENGAGE THE SAFETY
STOP- Push in and turn the Safety
Stop knob counterclockwise to place
the gun in the Open detented position. Figure 4. Disengage the Safety Stop
Manual Valve Operation
The manual valves located on the each
Side Block control the flow of each
chemical component to the gun.
TOOLS REQUIRED
• 5/16” Nut driver
1. TO OPEN MANUAL VALVE-
Using the 5/16” nut driver, turn
manual valve counter clockwise
approximately three full turns.
WARNING: NEVER OPEN A MANUAL VALVE
UNLESS THE SIDE BLOCK IS SECURED TO THE
GUN, OR THE EXIT PORT IS DIRECTED INTO A
SUITABLE CONTAINER. Figure 5. Manual Valves
NOTE:
Triggering of the gun with the
manual valves closed may cause
crossover if there is any residual
chemical in the gun ports.
2. TO CLOSE MANUAL VALVE- Using the 5/16” nut driver, turn manual valve
fully clockwise.
WARNING: TO PREVENT ACCIDENTAL GUN OPERATION, ALWAYS ENGAGE THE SAFETY STOP,
CLOSE BOTH MANUAL VALVES AND DISCONNECT THE AIR SUPPLY BEFORE SERVICING THE GUN,
OR ANY TIME THE GUN IS NOT IN USE.

GAP Pro Spray Gun
10 36943-1, Issue 1
Air Hose Configurations
TOOLS REQUIRED
• 3/16” Hex Key
• (2) 6” Adjustable Wrench
The GAP PRO Gun design allows for two different Air Hose configurations. The
standard configuration has the air connection at the base of the handle. The optional
configuration has the air connection at the rear of the gun. To change to the optional
configuration proceed as follows:
Figure 6. Air Hose Configuration
WARNING: BEFORE ATTEMPTING THIS PROCEDURE, CLOSE BOTH MANUAL VALVES, ENGAGE
THE SAFETY STOP, AND DISCONNECT THE AIR FROM THE GUN.
1. REMOVE THE AIR HOSE- Using a 6” Adjustable Wrench remove the Air Hose
from the Long Pipe Nipple at the base of the gun handle.
2. REMOVE THE LONG PIPE NIPPLE- Using a 6” Adjustable Wrench, remove
the Long Pipe Nipple from the base of the gun handle.
3. REMOVE THE PIPE PLUG- Using the 3/16” Hex Key, remove the Pipe Plug
from the back of the gun.
4. INSTALL THE PIPE PLUG- Using the 3/16” Hex Key, install the Pipe Plug in the
base of the gun handle in the hole previously occupied by the Air Hose.
5. INSTALL THE PIPE NIPPLE (Supplied with Gun)- Using a 6” Adjustable
Wrench, install the Pipe Nipple in the back of the gun.
6. INSTALL THE AIR HOSE- Using a 6” Adjustable Wrench, connect the Air Hose
to the Pipe Nipple at the back of the gun.

Operating Manual Operation
3/10/04 11
Initial Set Up Procedure
TOOLS REQUIRED
• 5/16” Spintite • Gun Cleaner
• (2) 6” Adjustable Wrench • (2) Clean Container
• Clean Rag
1. CLOSE BOTH MANUAL VALVES-
2. ENGAGE THE SAFETY STOP-
3. INSTALL THE FEMALE QUICK DISCONNECT FITTING- Using two 6”
Adjustable Wrenches install the Female Quick Disconnect Fitting on to the Air
Supply Hose which is bundled with the Chemical Supply Hoses.
4. CONNECT THE CHEMICAL HOSES- Using two 6” Adjustable Wrenches
connect the A and R Chemical Hoses to the corresponding A and R Side Blocks.
5. PRESSURIZE THE CHEMICAL HOSES- Pressurize the A and R Chemical
Hoses and check for leaks.
NOTE:
The A (Isocyanate) and R (Resin)
hose connection thread sizes are
different, making it virtually
impossible to improperly connect
the hoses. The, A (Isocyanate)
thread is 1/2-20, whereas the R
(Resin) thread is 9/16-18. 6. CHECK THE PROPORTIONING UNIT- Check the Proportioning Unit for
proper hose temperature, heater temperature, and pressure.
7. CONNECT THE AIR SUPPLY- Connect the Air Hose to the Quick Disconnect
Fitting on the Air Supply Hose.
8. OPEN BOTH MANUAL VALVES-
9. DISENGAGE THE SAFETY STOP-
10. TEST SPRAY OFF TARGET-
Daily Start Up Procedure
TOOLS REQUIRED
• 5/16” Spintite
IMPORTANT: Before attempting the following procedures, make sure the Side
Blocks are properly attached to the gun, the proportioning unit is at the desired
temperature and pressure, and the system is ready for operation.
1. CONNECT THE AIR SUPPLY- Connect the Air Hose to the Quick Disconnect
Fitting on the Air Supply Hose and check for proper Mixing Chamber movement.
2. OPEN BOTH MANUAL VALVES-
3. DISENGAGE THE SAFETY STOP-
4. TEST SPRAY OFF TARGET-

GAP Pro Spray Gun
12 36943-1, Issue 1
Daily Shutdown Procedure
TOOLS REQUIRED
• 5/16” Spintite
IMPORTANT: Follow this procedure whenever the gun is out of service for any
length of time.
1. PERFORM PROPORTIONING UNIT DAILY SHUT-DOWN PROCEDURE-
2. CLOSE BOTH MANUAL VALVES-
3. ENGAGE THE SAFETY STOP-
4. DISCONNECT THE AIR SUPPLY- Disconnect the Air Hose from the Quick
Disconnect Fitting on the Air Supply Hose.
Important Do Not perform steps 4 through 8 if gun is to be serviced following
shutdown.
5. GREASE MIXING CHAMBER- Insert the Gusmer GAP Gun Chamber Lubricant
Needle into nozzle of the mixing chamber. Dispense a small amount of lubricant
into mixing chamber.
NOTE:
To determine the correct amount,
to dispense, remove the air cap.
While dispensing view the
chamber area. When lubricant
becomes visible, an adequate
amount has been dispensed. 6. CONNECT THE AIR SUPPLY- Connect the Air Hose to the Quick Disconnect
Fitting on the Air Supply Hose.
7. TRIGGER GUN- Leave the Safety Stop engaged and trigger the gun 2 to 3 times to
discharge excess lubricant.
8. DISCONNECT THE AIR SUPPLY- Disconnect the Air Hose from the Quick
Disconnect Fitting on the Air Supply Hose.

Operating Manual Servicing Procedures
3/10/04 13
SERVICING PROCEDURES
Side Block Service Procedure
TOOLS REQUIRED
• 5/16” Spintite • Clean Out Drills
• 6” Adjustable Wrench • Gun Cleaner
• 1/2” Wrench • Brass Brushes
• Cotton Swabs
The Side Block Components consist of the following:
NOTE:
Consult the GAP PRO Spray Gun
Parts Identification Manual
(P/N 36943-ID) for specific
Part Numbers.
Figure 7. Side Block Component Removal / Installation
( R-Side Block shown )
1. PERFORM SHUTDOWN PROCEDURE- See the Daily Shutdown Procedure on
Page 12.
2. INSPECT THE SCREEN SCREW ASSEMBLIES- Using the 6” Adjustable
Wrench remove the A- Side Block Screen Assembly. Inspect the Screen Screw Seal
for damage. Thoroughly rinse the Screen and dry. Inspect the Screen by holding it
up to a bright light. The Screen mesh should be free of particles and varnish build-
up. Replace as required. Repeat steps for R- Side Block Screen Assembly.
3. REMOVE THE GUN FROM THE SIDE BLOCKS- Using the 5/16” Spintite,
alternately loosen the Side Block Mounting Screws. Carefully separate each Side
Block from the Gun Block. Wipe mating surfaces clean with a rag soaked in gun
cleaner.
4. REMOVE THE SIDE SEAL ASSEMBLY- Using the 1/2” Wrench, remove the
Check Valve Retainer/Side Seal Assembly from the Side Block.

GAP Pro Spray Gun
14 36943-1, Issue 1
5. CLEAN AND INSPECT THE SIDE SEAL ASSEMBLY COMPONENTS–
Remove the Check Valve. Clean the valve with gun cleaner. Inspect, and replace if
damaged. Remove the Side Seal. Inspect it, and the O-Ring, replace if damaged.
WARNING: DO NOT CLEAN THE SIDE SEAL(S) WITH A POCKETKNIFE, RAZOR BLADE, OR ANY
OTHER TOOL WHICH COULD MAR OR SCRATCH THE SUFRACE. USE A WOODEN / PLASTIC
SCRAPER TOOL OR BRASS BRUSH INSTEAD.
NOTE:
Repeat Steps 4, 5, and 6 for the
opposite Side Block and proceed
to Step 7.
6. CLEAN ALL COMPONENTS THOROUGHLY-Using the appropriate Brass
Brushes, Clean Out Drills, etc. remove residual chemical from the Gun Block. This
is important to ensure unrestricted movement of the Mixing Chamber. Use Cotton
Swabs soaked with Gun Cleaner if necessary.
7. REINSTALL THE SIDE SEAL
ASSEMBLY-
a) Place Check Valve Assembly
in the Check Valve Retainer
and thread into the Side
Block by hand. Using a 1/2”
Wrench tighten the Side Seal
Assembly by one quarter of a
full turn and No More.
WARNING: TIGHTENING ANY MORE
THAN ONE QUARTER OF A TURN CAN
DAMAGE THE CHECK VALVE AND OR
RETAINER AND MAY CAUSE LEAKAGE
WHEN THE GUN IS PRESSURIZED.
Figure 8. Tightning the Check Valve
Retainer
b) Place Spring In Check Valve Retainer
c) Lightly coat the O-Ring with grease and install it on the Side Seal.
d) Push the Side Seal into Check Valve Retainer until the O-Ring engages the
detent groove and remains in place.
8. REINSTALL THE SIDE BLOCKS ON THE GUN BLOCK- Using the 5/16”
Spintite, alternately tighten the A and R Side Blocks to the Gun Block with the two
mounting screws. Make sure to sufficiently tighten the screws equally to prevent
leakage.
9. PERFORM START UP PROCEDURE- See Daily Start Up Procedure on Page 11.
Mixing Chamber and Gun Block Service Procedure
TOOLS REQUIRED
• 5/16” Spintite • 6” Pliers
• Brass Brushes
• 3/16” Open End Wrench
(or Needle Nose Pliers) • Clean Out Drills
• 6” Adjustable Wrench • Gun Cleaner

Operating Manual Servicing Procedures
3/10/04 15
1. PERFORM SHUTDOWN PROCEDURE- See the Daily Shutdown Procedure on
Page 12.
2. REMOVE THE FLAT SPRAY TIP ASSEMBLY- Using the 6” Adjustable
Wrench remove the Flat Tip Assembly from the end of the Mixing Module.
NOTE:
If the gun has a Round Pattern
Spray Tip, skip Step 2 and proceed
to Step 3.
3. REMOVE AIR CAP- Remove the Air Cap from the front of the gun by turning it
counter-clockwise.
4. REMOVE THE GUN FROM THE SIDE BLOCKS- Using the 5/16” Spintite,
alternately loosen the Side Block Mounting Screws. Carefully separate each Side
Block from the Gun Block. Wipe mating surfaces clean with a rag soaked in gun
cleaner. If the Side Blocks require servicing see the Side Block Service Procedure
on page 13.
NOTE:
Consult the GAP PRO Spray Gun
Parts Identification Manual
(P/N 36943-ID) for specific
Part Numbers.
Figure 9. Mixing Chamber and Gun Block Removal/Installation
5. REMOVE AND SERVICE THE GUN BLOCK- Using the 5/16” Spintite, remove
the two Gun Block Mounting Screws. Slide the block away from the gun. Wipe
mating surfaces clean with a rag soaked in gun cleaner. Clean the Gun Block with
gun cleaner and Brass Brushes to remove any built up foam, crystallized Isocyanate,
etc. This is important to ensure unrestricted movement of the Mixing Chamber.
6. REMOVE AND SERVICE THE MIXING CHAMBER- Using the 3/16” Open
End Wrench or Needle Nose Pliers, hold the end of the Piston Rod. Turn the Mixing
Chamber by hand counter clockwise until it comes free. Clean the Mixing Chamber
with gun cleaner and clean out drills as required. Inspect it for damage, and replace
if necessary.
7. REINSTALL THE MIXING CHAMBER- Using the 3/16” Open End Wrench or
Needle Nose Pliers, hold the flat end of the Piston Rod. Thread the Mixing Chamber
onto the end of the Piston Rod by hand.
8. REINSTALL THE GUN BLOCK- Slide the Gun Block over the Mixing Chamber
and toward the gun. Using the 5/16” Spintite, install the Gun Block Mounting
Screws. Make sure to sufficiently tighten the screws equally to prevent leakage.

GAP Pro Spray Gun
16 36943-1, Issue 1
9. REINSTALL THE SIDE BLOCKS ON THE GUN BLOCK- Using the 5/16”
Spintite, alternately tighten the A and R Side Blocks to the Gun Block with the two
mounting screws. Make sure to sufficiently tighten the screws equally to prevent
leakage.
10. PERFORM START UP PROCEDURE- See Daily Start Up Procedure on Page 11.
End Cap and Air Piston O-Ring Service Procedure
TOOLS REQUIRED
• 5/16” Spintite • 9/64” Hex Key
• 7/64” Ball Point Hex Key • 6” Pliers
• Lubriplate Grease
NOTE:
If only the End Cap O-Ring and/or
Safety Stop Cup Seal requires
replacing, see the
End Cap O-Ring and Safety Stop
Cup Seal Service Procedure on
page 18. • 3/16” Open End Wrench
(or Needle Nose Pliers) • Retaining Ring Pliers
1. PERFORM SHUTDOWN PROCEDURE- See the Daily Shutdown Procedure on
Page 12.
2. REMOVE THE GUN FROM THE SIDE BLOCKS- Using the 5/16” Spintite,
alternately loosen the Side Block Mounting Screws. Carefully separate each Side
Block from the Gun Block. Wipe mating surfaces clean with a rag soaked in gun
cleaner. If the Side Blocks require servicing see the Side Block Service Procedure
on page 13.
3. REMOVE THE GUN BLOCK- Using the 5/16” Spintite, remove the two Gun
Block Mounting Screws. Carefully remove the Gun Block from the rest of the gun.
If removal is difficult, remove any dried chemical from the gun. Wipe mating
surfaces clean with a rag soaked in gun cleaner. Be sure to retain the O-Ring located
between the Gun Block and Mounting Flange.
4. REMOVE THE MIXING CHAMBER- Using the 3/16” Open End Wrench or
Needle Nose Pliers, hold the end of the Piston Rod. Turn the Mixing Chamber by
hand counter clockwise until it comes free. If chamber requires servicing, see the
Mixing Chamber and Gun Block Service Procedure.
5. DISENGAGE THE SAFETY STOP- Push in and turn the Safety Stop knob
counterclockwise to place the gun in the Open detented position.
6. REMOVE CYLINDER CLAMP- Using the 9/64” Ball Point Hex Key remove the
Socket Head Cap Screw and Clamp from the rear the Air Cylinder.
7. REMOVE THE RETAINING RING- Using the Retaining Ring Pliers remove the
Retaining Ring, which maintains the End Cap position in the Air Cylinder.
8. REMOVE THE END CAP/SAFETY STOP ASSEMBLY- Pull the Safety Stop
until it, and the attached End Cap come free from the Air Cylinder. Be sure to retain
the Piston Spring located inside of the Air Cylinder.
NOTE:
Removing the End Cap will require
some force since the
O-Ring is tightly compressed
9. INSPECT THE END CAP O-RING- Inspect the O-Ring. If damaged remove it
and install a new O-Ring after lightly coating it with Lubriplate Grease.

Operating Manual Servicing Procedures
3/10/04 17
Figure 10. End Cap and Piston Assembly
10. REMOVE THE PISTON ASSEMBLY- Using the 6” Pliers take hold of the Piston
and pull the assembly out of the Air Cylinder.
WARNING: TAKE CARE NOT TO DAMGE THE PISTON OR THE AIR CYLINDER WALL WHEN
REMOVING THE PISTON ASSEMBLY.
11. DISASSEMBLE THE
PISTON ASSEMBLY-
Remove the Retainer Ring
from the Piston Assembly.
Slide the Piston Shaft
Assembly out from the
backside of the Piston.
12. INSPECT THE O-RINGS-
Inspect the O-Rings and
remove if damaged. Carefully
install the new O-Rings after
applying Lubriplate Grease.
Figure 11. Piston Assembly
13. REASSEMBLE THE PISTON ASSEMBLY- Slide the Piston Shaft Assembly in
through the backside of the Piston, taking care not to damage the O-Rings. Install
the Retainer Ring on the Piston Assembly.
14. REINSTALL THE PISTON ASSEMBLY- Insert the Piston Assembly into the Air
cylinder.
15. REINSTALL THE END CAP ASSEMBLY AND PISTON SPRING- Center the
Piston Spring over the raised portion of the Piston and insert the End Cap into the
Air Cylinder. Press the End Cap until it moves past the undercut groove in the Air
Cylinder. This groove is where the Retaining Ring nests. Maintain pressure on the
End Cap, making sure the groove remains visible, and install the Retaining Ring
using the Retaining Ring Pliers.

GAP Pro Spray Gun
18 36943-1, Issue 1
16. REINSTALL CYLINDER CLAMP - Using the 9/64” Ball Point Hex Key reinstall
the Socket Head Cap Screw and Cylinder Clamp on the rear of the Air Cylinder.
WARNING: INSERT THE RETAINING RING COMPLETELY INTO THE GROOVE SO THAT THE END
CAP WILL REMAIN IN THE AIR CYLINDER WHEN THE GUN HAS AIR PRESSURE APPLIED TO IT.
KEEP CLEAR OF THE CAP WHEN FIRST REAPPLYING AIR PRESSURE OR TRIGGERING THE GUN
AFTER REASSEMBLY IN CASE OF IMPROPER RETAINING RING INSTALLATION.
17. REINSTALL THE MIXING CHAMBER- Using the 5/16” Spintite, or Needle
Nose Pliers, hold the end of the Piston Rod. Thread the Mixing Chamber onto the
threaded portion of the Piston Rod by hand until it is snug.
18. REINSTALL THE GUN BLOCK- Slide the Gun Block over the Mixing Chamber
and toward the gun. Using the 5/32” Hex Key, install the Gun Block Mounting
Screws. Make sure to sufficiently torque the screws.
19. REINSTALL THE SIDE BLOCKS ON THE GUN BLOCK- Using the 5/16”
Spintite, alternately tighten the A and R Side Blocks to the Gun Block with the two
mounting screws. Make sure to sufficiently tighten the screws equally to prevent
leakage.
20. PERFORM START UP PROCEDURE- See Daily Start Up Procedure on Page 11.
End Cap O-Ring and Safety Stop Cup Seal Service Procedure
TOOLS REQUIRED
• Retaining Ring Pliers • 6” Pliers
• 9/64” Ball Point Hex Key • 5/64” Hex Key
• 5/16” Spintite • Lubriplate Grease
1. PERFORM SHUTDOWN PROCEDURE- See the Daily Shutdown Procedure on
Page 12.
2. REMOVE THE GUN FROM THE SIDE BLOCKS- Using the 5/16” Spintite,
alternately loosen the Side Block Mounting Screws. Carefully separate each Side
Block from the Gun Block. Wipe mating surfaces clean with a rag soaked in gun
cleaner. If the Side Blocks require servicing see the Side Block Service Procedure
on page 13.
3. REMOVE CYLINDER CLAMP- Using the 9/64” Ball Point Hex Key remove the
Socket Head Cap Screw and Clamp from the rear the Air Cylinder.
4. REMOVE THE RETAINING RING- Using the Retaining Ring Pliers remove the
Retaining Ring, which holds the End Cap in place in the Air Cylinder.
NOTE:
Removing the End Cap will require
some force since the
O-Ring is tightly compressed
5. REMOVE THE END CAP/SAFETY STOP ASSEMBLY- Remove the End Cap
and retain the Piston Spring located inside of the Air Cylinder for future use.

Operating Manual Servicing Procedures
3/10/04 19
Figure 12. End Cap Assembly
6. INSPECT THE END CAP O-RING- Inspect the O-Ring. If damaged remove it
and install a new O-Ring after lightly coating it with Lubriplate Grease.
7. REMOVE THE SAFETY
STOP MECHANISM-
Using the 5/64” Hex Key
loosen the two setscrews on
the Stop Knob. Slide the
knob off the shaft of the
Stop Pin. Retain the Shaft
Spring. Pull the Stop Pin
out of the End Cap.
Figure 13. Safety Stop Assembly
8. REPLACE CUP SEAL- Remove and replace the Cup Seal located in the End Cap
if necessary. Lubricate the new cup seal and install it making sure that the “cup” is
facing the Air Cylinder.
9. REINSTALL THE SAFETY STOP MECHANISM- Insert the Stop Pin into the
End Cap. Slide the Shaft Spring and Stop Knob onto the shaft of the Stop Pin.
Using the 5/64” Hex Key reinstall the two set screws in the Stop Knob. Make sure
the knob is secure.
10. REINSTALL THE END CAP/SAFETY STOP ASSEMBLY- Center the Piston
Spring over the raised portion of the Piston. Line up the raised portion of the End
Cap with the inside diameter of the Piston Spring and insert the End Cap into the Air
Cylinder. Press the End Cap until it moves past the undercut groove in the Air
Cylinder. This groove is where the Retaining Ring nests. Maintain force on the End
Cap, making sure the groove remains visible, and install the Retaining Ring using
the Retaining Ring Pliers.
11. REINSTALL CYLINDER CLAMP - Using the 9/64” Ball Point Hex Key reinstall
the Socket Head Cap Screw and Cylinder Clamp on the rear of the Air Cylinder.

GAP Pro Spray Gun
20 36943-1, Issue 1
WARNING: INSERT THE RETAINING RING COMPLETELY INTO THE GROOVE SO THAT THE END
CAP WILL REMAIN IN THE AIR CYLINDER WHEN THE GUN HAS AIR PRESSURE APPLIED TO IT.
KEEP CLEAR OF THE CAP WHEN FIRST REAPPLYING AIR PRESSURE OR TRIGGERING THE GUN
AFTER REASSEMBLY IN CASE OF IMPROPER RETAINING RING INSTALLATION.
12. REINSTALL THE SIDE BLOCKS ON THE GUN BLOCK- Using the 5/16”
Spintite, alternately tighten the A and R Side Blocks to the Gun Block with the two
mounting screws. Make sure to sufficiently tighten the screws equally to prevent
leakage.
13. PERFORM START UP PROCEDURE- See Daily Start Up Procedure on Page 11.
Trigger Valve O-Ring Procedure
TOOLS REQUIRED
• 6” Adjustable Wrench • Pin Punch, 1/4” diameter or less
• 6” Pliers • Ball Peen Hammer
• 5/16” Spintite • Gun Cleaner
• 3/16” Hex Key • Clean Rags
• Lubriplate Grease
1. PERFORM SHUTDOWN PROCEDURE- See the Daily Shutdown Procedure
on Page 12.
2. REMOVE THE GUN FROM THE SIDE BLOCKS- Using the 5/16” Spintite,
alternately loosen the Side Block Mounting Screws. Carefully separate each Side
Block from the Gun Block. Wipe mating surfaces clean with a rag soaked in gun
cleaner. If the Side Blocks require servicing see the Side Block Service Procedure
on page 13.
3. REMOVE THE 1/8” PIPE PLUG FROM THE GUN- Using the 3/16“ Hex Key
remove the 1/8” Pipe Plug from the gun.
4. REMOVE TRIGGER LEVER- Using the 6” Adjustable Wrench and the 6” Pliers
remove the Screw and Locknut that hold the Trigger Lever in place. Remove the
Trigger Lever.
NOTE:
Guns configured with the air
supply connected to the rear of the
Gun, as opposed to the base of the
Gun Handle, require removal of the
Air Hose and Pipe Nipple using a
6” Adjustable Wrench.
5. REMOVE VALVE RETAINER NUT- Using the 6” Adjustable Wrench, remove
the Valve Retainer Nut. This is the hex shaped nut that surrounds the brass Valve
Spool and holds it in place.
6. REMOVE THE VALVE SPOOL- Using the 6” Pliers carefully take hold of the
end of the Valve Spool and remove it from the gun. A spring will come out with it.
Make sure not to loose this spring as it belongs in the hole at the end of the Spool.
7. REPLACE THE O-RINGS- If necessary, replace the O-Rings on the Valve Spool
after applying a thin coat of Lubriplate Grease to them.