Graco 965660 Instruction Manual

Instructions - User Guide
INSTRUCTIONS
This manual contains important
warnings and information.
READ AND KEEP FOR REFERENCE.
Graco Inc. P.O. Box 1441 Minneapolis, MN 55440-1441
COPYRIGHT 2000, Graco Inc.
Graco Inc. is registered to I.S. EN ISO 9001
309239
Rev. A
First choice when
quality counts™
Air Powered, Falcon™
Variable Ratio Mini-Cat
Variable Ratio Mini-CatVariable Ratio Mini-Cat
Variable Ratio Mini-Cat
Proportioner
ProportionerProportioner
Proportioner
50 psi (0.345 MPa, 3.5 bar) Maximum Air Inlet Pressure
Model 965660, 1:1 to 4:1 Ratio Range
550 psi (3.8 MPa, 37.0 bar) Maximum Fluid Working Pressure
Model 965661, 2:1 to 8:1 Ratio Range
625 psi (4.3 MPa, 42.0 bar) Maximum Fluid Working Pressure
U.S. Patent No. 5,158,438
U.S. Patent No. 5,209,152

2309239 Instructions - Parts List

309239 Instructions - Parts List
Table of Contents 3
Table of Contents
Table of ContentsTable of Contents
Table of Contents
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Warning Symbol . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Caution Symbol . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Equipment Misuse Hazard . . . . . . . . . . . . . . . . . . 5
Pressurized Equipment Hazard . . . . . . . . . . . . . . 6
Moving Parts Hazard . . . . . . . . . . . . . . . . . . . . . . 6
Fire And Explosion Hazard. . . . . . . . . . . . . . . . . . 7
Toxic Fluid Hazard . . . . . . . . . . . . . . . . . . . . . . . . 7
Plural Component Material Hazard . . . . . . . . . . . 7
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Connect the Fluid Supply Lines . . . . . . . . . . . . . . 8
Connect the Static Mixer . . . . . . . . . . . . . . . . . . . 8
Connect the Air Supply Line. . . . . . . . . . . . . . . . 10
Connect the Solvent Supply Line . . . . . . . . . . . . 10
Ground the System . . . . . . . . . . . . . . . . . . . . . . 10
Ratio Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Determining the Ratio. . . . . . . . . . . . . . . . . . . . . 11
Base is Pre-reduced . . . . . . . . . . . . . . . . . . 11
Calculating the Scale Setting . . . . . . . . . . . . . . . 12
Setting the Ratio . . . . . . . . . . . . . . . . . . . . . . . . . 12
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Pressure Relief Procedure . . . . . . . . . . . . . . . . . 13
Flushing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Flushing the System . . . . . . . . . . . . . . . . . . 14
Starting the Pump . . . . . . . . . . . . . . . . . . . . 14
Standard Operation Flushing . . . . . . . . . . . . 14
Checking the Ratio . . . . . . . . . . . . . . . . . . . . 14
Two Color Flushing. . . . . . . . . . . . . . . . . . . . 16
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Troubleshooting Techniques . . . . . . . . . . . . . . . . 17
To isolate the problem: . . . . . . . . . . . . . . . . . 17
Troubleshooting Chart. . . . . . . . . . . . . . . . . . . . . 18
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Bearing and Pump Lubrication . . . . . . . . . . . . . . 19
Air Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Proportioning Pump Removal . . . . . . . . . . . . . . . 19
Proportioning Pump Installation . . . . . . . . . . . . . 19
Air Motor Service. . . . . . . . . . . . . . . . . . . . . . . . . 20
Throat Packing Disassembly . . . . . . . . . . . . 20
Throat Packing Reassembly. . . . . . . . . . . . . 20
Cylinder and Piston Disassembly . . . . . . . . . 21
Cylinder and Piston Reassembly . . . . . . . . . 21
Actuator Valve Disassembly. . . . . . . . . . . . . 22
Actuator Valve Reassembly . . . . . . . . . . . . . 22
Director Valve Disassembly . . . . . . . . . . . . . 24
Director Valve Reassembly . . . . . . . . . . . . . 24
Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Model 244143 Air Motor . . . . . . . . . . . . . . . . . . . 26
Models 965660 and 965661 Variable Ratio
Mini-Cat Proportioner . . . . . . . . . . . . . . . . . . . . . 28
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Graco Standard Warranty . . . . . . . . . . . . . . . . . . . . 34
Graco Phone Number . . . . . . . . . . . . . . . . . . . . . . . 34

Symbols
4309239 Instructions - Parts List
Symbols
SymbolsSymbols
Symbols
Warning Symbol
Warning SymbolWarning Symbol
Warning Symbol
This symbol alerts you to the possibility of serious injury
or death if you do not follow the instructions.
Caution Symbol
Caution SymbolCaution Symbol
Caution Symbol
This symbol alerts you to the possibility of damage to or
destruction of equipment if you do not follow the instruc-
tions.
Terms
TermsTerms
Terms
Variable Ratio Mini-Cat Pump: This pump automati-
cally proportions and mixes two or three fluids in a pre-
scribed ratio, which is variable within the ranges listed
on the cover.
Base: One of two reactive chemicals used in a plural
component system. Also called polyol or resin.
Reducer: Used to thin base. Also called true solvent or
dilutent.
Catalyst: The fluid which reacts with the base fluid. Also
called hardener.
Part: An undefined unit of measurement. When you
determine the size of the unit (ounce, pint, gallon), use
that measurement consistently in setting up your sys-
tem.
Spray Gun: This term refers to any type of spray gun or
dispensing valve used to spray or dispense the fluid
being pumped.
Ratio: Ratio refers to the simultaneous output of a cer-
tain volume of fluid by the primary and secondary
pumps.
Primary Pump: The pump directly under the air motor. It
usually pumps the base fluid.
Secondary Pump: The pump located along the pivot
beam. It usually pumps the catalyst.
WARNING CAUTION

309239 Instructions - Parts List
WARNING 5
WARNING
WARNINGWARNING
WARNING
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture or malfunction and result in serious injury.
•This equipment is for professional use only.
•Read all instruction manuals, tags, and labels before operating the equipment.
•Use the equipment only for its intended purpose. If you are not sure, call your Graco distributor.
•Do not alter or modify this equipment. Use only genuine Graco parts and accessories.
•Check equipment daily. Repair or replace worn or damaged parts immediately.
•Do not exceed the maximum working pressure stated on the equipment or in the Technical Data for
your equipment. Do not exceed the maximum working pressure of the lowest rated component in
your system.
•Use fluids and solvents which are compatible with the equipment wetted parts. Refer to the Techni-
cal Data section of all equipment manuals. Read the fluid and solvent manufacturer’s warnings.
•Handle hoses carefully. Do not pull on hoses to move equipment.
•Route hoses away from traffic areas, sharp edges, moving parts, and hot surfaces. Do not expose
Graco hoses to temperatures above 66° C (150°F) or below -40°C (-40°F).
•Wear hearing protection when operating this equipment.
•Do not move or lift pressurized equipment.
•Comply with all applicable local, state, and national fire, electrical, and safety regulations.
INSTRUCTIONS

WARNING
6309239 Instructions - Parts List
WARNING
WARNINGWARNING
WARNING
PRESSURIZED EQUIPMENT HAZARD
Fluid dispensed from the spray gun, leaks or ruptured components can splash in the eyes or on the skin
and cause serious injury.
•Do not point the valve at anyone or at any part of the body.
•Do not put your hand or fingers over the spray nozzle.
•Do not stop or deflect leaks with your hand, body, glove or rag.
•Always have the tip guard and the trigger guard on the gun/valve when dispensing.
•Be sure the valve trigger safety operates before dispensing.
•Lock the valve trigger safety when you stop dispensing.
•Follow the “Pressure Relief Procedure” on page 13 if the nozzle clogs and before cleaning, checking
or servicing the equipment.
•Tighten all fluid connections before operating the equipment.
•Check the hoses, tubes, and couplings daily. Replace worn, damaged, or loose parts immediately.
Permanently coupled hoses cannot be repaired; replace the entire hose.
MOVING PARTS HAZARD
Moving parts can pinch or amputate your fingers.
•Keep clear of all moving parts when starting or operating the pump.
•Before checking or servicing the equipment, follow the “Pressure Relief Procedure” on page 13 to
prevent the equipment from starting unexpectedly.

309239 Instructions - Parts List
WARNING 7
WARNING
WARNINGWARNING
WARNING
FIRE AND EXPLOSION HAZARD
Improper grounding, poor ventilation, open flames or sparks can cause a hazardous condition and result
in a fire or explosion and serious injury.
•Ground the equipment and the object being dispensed to. Refer to “Ground the System” on page 10.
•If there is any static sparking or you feel an electric shock while using this equipment, stop dispens-
ing immediately. Do not use the equipment until you identify and correct the problem.
•Provide fresh air ventilation to avoid the buildup of flammable fumes from solvents or the fluid being
dispensed.
•Keep the dispense area free of debris, including solvent, rags, and gasoline.
•Do not smoke in the dispense area.
•Do not turn on or off any light switch in the dispense area while dispensing or while operating if
fumes are present.
TOXIC FLUID HAZARD
Hazardous fluid or toxic fumes can cause serious injury or death if splashed in the eyes or on the skin,
inhaled, or swallowed.
•Know the specific hazards of the fluid you are using.
•Store hazardous fluid in an approved container. Dispose of hazardous fluid according to all local,
state and national guidelines.
•The air motor exhausts any fluids added to the input air, such as oil or antifreeze.
•Always wear protective eyewear, gloves, clothing and respirator as recommended by the fluid and
solvent manufacturer.
PLURAL COMPONENT MATERIAL HAZARD
Graco does not manufacture or supply any of the reactive chemical components that are used in this
equipment and is not responsible for their effects. Because of the vast number of chemicals that could
be used and their varying chemical reactions, the buyer and user of this equipment should determine all
facts relating to the materials used, including any of the potential hazards involved. Particular inquiry and
investigation should be made into potential dangers relating to toxic fumes, fires, explosions, reaction
times and exposure of human beings to the individual components or their resultant mixtures. Graco
assumes no responsibility for loss, damage, expense or claims for bodily injury or property damage,
direct or consequential, arising from use of such chemical components.

Specifications
8309239 Instructions - Parts List
Specifications
SpecificationsSpecifications
Specifications
The following chart gives specifications for the Mini-Cat
pumps, using No. 10 weight oil. The volumetric ratio is
expressed as the proportion of the volume of fluid of the
primary pump compared to the volume of fluid of the
secondary pump.
For example, Model 965660 has a minimum volumetric
ratio of 1:1. At this setting the primary and secondary
pumps combined will deliver an output of 1.1 GPM (4.2
liter/min). The minimum volumetric ratio for Model
965660 is 1:1 and the combined output at that setting is
0.7 GPM (2.6 liters/min).
Installation
InstallationInstallation
Installation
The Typical Installation drawings (Figure 1 and Figure
2) are only guides to setting up the complete Variable
Ratio Mini-Cat system. For assistance in designing a
system to suit your particular needs, contact your near-
est Graco representative.
NOTE: The reference numbers and letters in the text
correspond to the numbers and letters in the drawings.
Location
LocationLocation
Location
Install the proportioner on a flat floor surface.
Connect the Fluid Supply Lines
Connect the Fluid Supply LinesConnect the Fluid Supply Lines
Connect the Fluid Supply Lines
Connect grounded fluid hoses to the 3/4 npt(f) pump
inlet fittings. If the unit will be pressure fed from sepa-
rate supply units, install a fluid pressure gauge at each
inlet.
NOTE: The pressurized fluid supplies must not exceed
1/4 of the operating fluid pressure of the pump. Pres-
sure above that level will feed right through the pump
and improper rationing will result.
Connect the Static Mixer
Connect the Static MixerConnect the Static Mixer
Connect the Static Mixer
Connect a static mixer to the 1/2 npt(m) manifold outlet.
Connect a grounded fluid hose and spray gun to the end
of the static mixer. Tighten all the fittings.
Model Pump Volumetric Ratio
Output Volume
GPM (liter/min.) at
40 CPM
Stall Pressure at
50 psi (0.34 MPa,
3.4 bar) inbound
Number Primary Secondary Min. Max. Min. Max. Min. Max.
965660 222015 222012 1:1 4:1 0.62 (2.3) 1.0 (3.8) 350
(2.4, 24)
550
(3.8, 38)
965661 222015 222019 2:1 8:1 0.56 (2.1) 0.75 (2.8) 420
(2.9, 29)
625
(4.2, 43)
Key for Figure 1 and Figure 2
AAtomizing Air Regulator KResin Supply Pail
BSelf Relieving Air Valve LSolvent Supply
CCatalyst Supply Shut-off Valve MAir Spray Gun
DGrounded Fluid Hose NAir Supply
ESampling Valve (resin) OStatic Mixer
FMix Manifold PFluid Regulator
GMini-Cat Proportioner RSolvent Shut-off Valve
HAir Oiler SColor Selector Manifold
IAir Filter TPressure Relief Valve
JMain Self Relieving Air Valve

309239 Instructions - Parts List
Installation 9
Figure 1 - Typical Installation for One Color System
Figure 2 - Typical Installation for Two Color System
TI0740A
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
T
Catalyst
TI0740A
Color 1
Color 2
Catalyst
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
T
K
S
R

Installation
10 309239 Instructions - Parts List
Connect the Air Supply Line
Connect the Air Supply LineConnect the Air Supply Line
Connect the Air Supply Line
NOTE: To ensure the maximum pump performance, be
sure that all the accessories used are properly sized to
meet your system requirements. Use only genuine
Graco parts and accessories.
In the air line, install an air filter to remove harmful dirt
and moisture from the compressed air supply. Install an
air line lubricator downstream from the air filter, the sup-
plied air regulator, and the bleed-type master air valve.
The lubricator provides automatic lubrication to the air
motor.
Connect a 1/2” minimum ID grounded air supply hose to
the 1/2 npt(f) port of the air regulator. Open the bleed-
type master air valve and set the air regulator to the
desired pressure, using the pressure gauge.
Connect the Solvent Supply Line
Connect the Solvent Supply LineConnect the Solvent Supply Line
Connect the Solvent Supply Line
Remove the coupling from the solvent inlet on the mix
manifold and install a grounded fluid supply from the
solvent pump.
Ground the System
Ground the SystemGround the System
Ground the System
Ground all of this equipment:
• Pump: Use a ground wire and clamp as shown in
Figure 3. Loosen the grounding lug locknut and
washer (X). Insert one end of a 12 ga. (1.5 mm²)
minimum ground wire (Y) into the slot in lug (Z) and
tighten the locknut securely. Connect the other end
of the wire to a true earth ground. Order part num-
ber 222011 Grounding Clamp and Wire.
• Fluid hoses: Use only grounded fluid hoses.
• Air hoses: Use only grounded air hoses.
• Spray Guns: Obtain grounding through connection
to a properly grounded fluid hose and pump.
• Fluid supply container: Follow your local code.
• Air compressor: Follow your local code.
• 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.
• All solvent pails used when flushing: Follow your
local code. Use only metal pails, which are conduc-
tive, placed on a grounded surface. Do not place
the pail on a non-conductive surface, such as paper
or cardboard, which interrupts the grounding conti-
nuity.
WARNING
The supplied bleed-type master air valve is required in
your system to relieve the air trapped between the
valve and the pump after the pump is shut off. Trapped
air can cause the pump to cycle unexpectedly, which
can result in serious injury.
WARNING
Fire and Explosion Hazard
Before operating the system, ground it as explained
below. Also read the Fire or Explosion Hazard section
on page 7.
Figure 3 - Pump Grounding Lug
W
X
Y
Z
6431

309239 Instructions - Parts List
Ratio Adjustment 11
Ratio Adjustment
Ratio AdjustmentRatio Adjustment
Ratio Adjustment
Understanding the terms used with the Variable Ratio
Mini-Cat proportioner, how it functions, and how to find
and set the correct ratios for your application is the key
to easier, more versatile operation of your proportioning
system.
Be sure to read and understand the terms on page 4
and the following information before operating the
equipment.
There are three main points when applying the use of
ratios:
1. Determine the ratio that is required.
2. Calculate the scale setting.
3. Set the ratio on the Variable Ratio Mini-Cat propor-
tioner.
Determining the Ratio
Determining the RatioDetermining the Ratio
Determining the Ratio
Set the ratio based on the following:
• If the fluids are supplied at a ready-to-spray vis-
cosity, simply set the ratio as explained under Set-
ting the Ratio on page 12.
• If the fluids are NOT supplied at ready-to-spray
viscosity and you must pre-reduce the base, the
ratio must be determined after the reducer is added
to the base, as instructed at right.
NOTE:
•Evaporation of the reducer in the base causes
changes in the ratio. To prevent evaporation,
store the base in a closed container.
•Some reducers have very little ability to lubri-
cate and many cause seals to dry out. To pro-
long the seal life, be sure your pump seals are
compatible with the base’s reducer. Contact
your Graco representative for the correct seals
to use.
Base is Pre-reduced
To determine the ratio of the base/reducer mixture to the
catalyst, follow the procedure in the example below.
Example:
The instructions on the can say “Mixer 5 parts base to 1
part catalyst. Then reduce 3 parts of this mixture to 1
part reducer.”
1. Add the parts of the base and catalyst to find the
parts mixture.
5 parts base
+ 1 parts catalyst
6 parts mixture
2. The next statement on the can says, “Reduce 3
parts of the mixture.” So divide the parts of the mix-
ture by 3 parts to find the parts reducer.
6 parts mixture
÷3 parts to reduce
2 parts reducer
3. To determine the ratio of the secondary pump, add
the appropriate parts base and parts reducer to find
the parts combined base/reducer.
5 parts base
+ 2 parts reducer
7 parts combined base/reducer to 1
part catalyst
The ratio of the secondary pump is 7:1.

Ratio Adjustment
12 309239 Instructions - Parts List
Calculating the Scale Setting
Calculating the Scale SettingCalculating the Scale Setting
Calculating the Scale Setting
The scale setting is determined either from the appropri-
ate chart or by using the formulas below.
NOTE: MR stands for Mix Ratio in the following formu-
las.
For Model 965660
Scale Setting = 16 [MR-1]
MR
For Model 965661
Scale Setting = 16 [MR-2]
MR
For example, for a 4:1 mix ratio with Model 965661 the
catalyst scribe mark should be set on:
Scale Setting = 16 [MR-2]
MR
Scale Setting = 16 [4--2]
MR = 8
Setting the Ratio
Setting the RatioSetting the Ratio
Setting the Ratio
To set or change the mix ratio, loosen the four adjusting
knobs. Pull up on the knob to disengage the thread.
Slide the catalyst to the desired scale setting and
retighten the adjusting knobs.
Ratio Setting for Model 965660
Ratio Setting for Model 965660
WARNING
Pressurized Equipment Hazard
To reduce the risk of serious injury, always follow the
Pressure Relief Procedure on page 13 before setting
or changing the mix ratio.
Volumetric
Ratio
Ratio
Setting
1.00:1 0
1.25:1 3.20
1.50:1 5.33
1.75:1 6.86
2.00:1 8.00
2.25:1 8.89
2.50:1 9.60
2.75:1 10.18
3.00:1 10.67
3.25:1 11.08
3.50:1 11.43
3.75:1 11.73
4.00:1 12.00
Volumetric
Ratio
Ratio
Setting
2.00:1 0
2.50:1 3.20
3.00:1 5.33
3.50:1 6.86
4.00:1 8.00
4.50:1 8.89
5.00:1 9.60
5.50:1 10.18
6.00:1 10.67
6.50:1 11.08
7.00:1 11.43
7.50:1 11.73
8.00:1 12.00

309239 Instructions - Parts List
Operation 13
Operation
OperationOperation
Operation
Pressure Relief Procedure
Pressure Relief ProcedurePressure Relief Procedure
Pressure Relief Procedure
1. Lock the spray gun safety latch.
2. Shut off the power source to the pump.
3. Close the bleed-type master air valve (required in
the system).
4. Unlock the spray gun safety latch.
5. Hold a metal part of the spray gun firmly to the side
of a grounded metal pail, and trigger the gun to
relieve fluid pressure.
6. Lock the spray gun safety latch.
7. Open the pressure relief valve, having a container
ready to catch the drainage. Leave the valve open
until you are ready to spray again.
8. If you suspect that the spray tip/nozzle or hose is
completely clogged or that pressure has not been
fully relieved after following the steps above, very
slowly loosen the tip guard retaining nut or hose end
coupling to relieve pressure gradually, then loosen
completely. Now clear the tip/nozzle or hose.
Flushing
FlushingFlushing
Flushing
The pumps, mixer manifold and other components were
tested with lightweight oil at the factory. Before operat-
ing the pump, thoroughly flush the Mini-Cat system to
prevent contamination of your fluids. Follow the Flush-
ing the System on page 14.
Flush the mixer, hose and gun often enough to prevent
fluid from reacting or curing in them. Contact your fluid
manufacturer for the effective pot life of the fluid you are
using.
WARNING
Pressurized Equipment Hazard
The system pressure must be manually relieved to pre-
vent the system from starting or spraying accidentally.
To reduce the risk of an injury from accidental spray
from the gun, splashing fluid, or moving parts, follow
the Pressure Relief Procedure whenever you:
•are instructed to relieve the pressure,
•stop spraying,
•check or service any of the system equipment,
•or install or clean the spray nozzle.
WARNING
To reduce the risk of fire, explosion, and serious injury
from static sparking and splashing, be sure to follow
these precautions before and during system flushing:
•Be sure the entire system and flushing pails are
properly grounded. Refer to Ground the System on
page 10.
•Wear eye protection.
•Follow the “Pressure Relief Procedure” before
flushing and before removing a spray tip.
•If a high pressure spray gun is being used, remove
the spray tip before flushing.
•Use the lowest possible fluid pressure and maintain
firm metal-to-metal contact between the spray gun
and pail during flushing,

Operation
14 309239 Instructions - Parts List
Flushing the System
1. Put the pump intake hoses into a 5 gallon (20 liter)
container of a compatible solvent. Refer to the fluid
manufacturer’s recommendations.
2. Start the pump as instructed below.
3. Do not install a spray tip yet. Hold a metal part of the
gun firmly to the side of a grounded metal pail.
Using the lowest possible fluid pressure, trigger the
gun into the pail.
4. When clean solvent comes from the spray gun,
release the trigger and carefully check all connec-
tions in the system for leaks.
5. Take the hoses out of the solvent, and trigger the
gun until all the solvent has been pumped out of the
hoses.
Starting the Pump
1. Close the bleed-type master air valve, and turn the
air regulator knob all the way out (counterclock-
wise).
2. Turn on the main air supply.
3. With the mixer manifold handle in the open (down)
position (see Figure 4), trigger the gun, slowly open
the bleed-type master air valve, and turn the air reg-
ulator knob clockwise until the pump starts to cycle.
4. Allow the pump to cycle slowly until all the air is
pushed out of the lines. Release the trigger - the
pump will stall against the pressure.
5. The manifold handle controls fluid flow. With the
lever of the manifold in the open (down) position,
base and catalyst are supplied to the gun. To stop
the flow, move the handle to the closed (up) posi-
tion.
Standard Operation Flushing
Use the solvent valves to flush contaminants and mixed
fluids from the mixer manifold, hose and spray gun. Fol-
low the procedure, below.
1. Start the solvent pump, and move the mixer mani-
fold handle to the closed (up) position. See Figure
4.
2. Open one of the solvent valves and trigger the gun
into the metal pail until thoroughly flushed. Release
the trigger.
3. Close the opened solvent valve, and open the other
solvent valve. Trigger the gun into the pail until thor-
oughly flushed. Release the trigger.
4. Open both solvent valves and continue flushing until
all contaminants and fluids are removed. Release
the trigger.
5. To flush the sampling valves, place a grounded
metal pail under the sampling valves. Turn the valve
handle to the open position. Flush until all contami-
nants and fluids are removed. Close the sampling
and solvent valves. The solvent valves should be
finger tight only, but must be tight enough to prevent
solvent from mixing with the fluid during operation.
6. Trigger the gun to relieve the pressure.
Checking the Ratio
1. Open the mixer manifold by moving the handle to
the down position. See Figure 4.
2. Set your operating pressure. After determining the
operating pressure, release the spray gun trigger
and lock the safety latch.
3. Close the mixer manifold by moving the handle to
the up position. See Figure 4.

309239 Instructions - Parts List
Operation 15
4. Open the sampling valve on the secondary pump
side approximately three turns. Open the sampling
valve on the primary pump side one turn. This will
prevent the pressure from building up on the sec-
ondary pump, which would open the relief valve.
5. Place a grounded waste container under the sam-
pling valve.
6. Open the mixer manifold (move the handle to the
down position). Use the sampling valve to adjust the
pressures to your normal operating pressure.
7. Close the mixer manifold (move the handle to the
up position). Put the sampling containers under the
sampling valves.
8. Open the mixer manifold. Check the ratio; make
sure the pressure is within 20% of your normal
operating pressure. Close the mixer manifold when
enough fluid has been dispensed into the sampling
containers.
NOTE: If the pressure readings are not within 20% of
your normal operating pressure, follow the procedure
Standard Operation Flushing on page 14, then take a
sample again.
If your sample ratio is incorrect, there is a problem with
the sampling valves, secondary pump setting, or pump
operation. Check the pump setting or service the sam-
pling valves or pump.
Figure 4 - Fluid Manifold
SOLVENT OUT MIXED FLUID OUT
SOLVENT
CATALYSTBASE BASE
SOLVENT
CATALYST
1
2
4
3
Solvent valve shown open.
Manifold handle shown closed (UP).
Solvent valve shown closed.
Manifold handle shown open (DOWN).
1
2
3
4
0242

Operation
16 309239 Instructions - Parts List
Two Color Flushing
When using a two color system, follow the procedure
below to obtain good color change results. Refer to Fig-
ure 2 on page 9.
1. Close the color valve at the color selector manifold
(S).
2. Close the catalyst shut-off valve (C).
3. Close the self-relieving air valve (B) on the Mini-Cat
proportioner.
4. Open the solvent shut-off valve (R).
5. Holding the spray gun against the side of a
grounded metal pail, trigger the gun until clean sol-
vent comes out.
6. Close the solvent supply valve (R).
7. Open the color valve (S).
8. Place a grounded waste container under the sam-
pling valves.
9. Slowly open the resin sampling valve (E) located on
the mix manifold (F) and allow the fluid to drain until
pure color comes out, then close the valve.
10. Open the catalyst supply valve (C).
11. Open the self relieving air valve (B).
12. Trigger the gun against a grounded metal pail until
full color comes out. The Mini-Cat proportioner is
now ready for operation.
NOTE: After making a color change, follow the proce-
dure Standard Operation Flushing on page 14 to clean
the mix manifold. This ensures that the internal check
valves within the mix manifold are clean.

309239 Instructions - Parts List
Troubleshooting 17
Troubleshooting
TroubleshootingTroubleshooting
Troubleshooting
Troubleshooting Techniques
Troubleshooting TechniquesTroubleshooting Techniques
Troubleshooting Techniques
Because the pumps are mechanically linked, the action
of one pump can affect the readings of the second
pump. Therefore, the key to successful troubleshooting
is to isolate the problem.
For example, the secondary pump pressure, as read on
the gauge, is low and sluggish during the pump change-
over. The most likely problem is a binding primary
pump.
To isolate the problem:
1. Relieve the pressure as instructed in the Pressure
Relief Procedure on page 13.
2. Remove the catalyst pump. Now you can verify the
operation of the primary pump alone.
a. Check for pump stalling on both the up and
down strokes.
b. Check for rapid gauge response during pump
change-over.
3. When the operation of the primary side has been
verified, reinstall the catalyst pump.
4. Disconnect the master pump connecting rod from
the pump and repeat the checks in step 2 (above)
on the secondary pump side.
WARNING
Pressurized Equipment Hazard
To reduce the risk of serious injury, including splashing
in the eyes or on the skin or injury from moving parts,
follow the Pressure Relief Procedure on page 13
before troubleshooting or servicing the equipment and
whenever you are instructed to relieve the pressure.
Use very low air pressure to the air motor when follow-
ing the procedure at right to isolate the problem or
doing any other troubleshooting requiring air pressure.
Moving Parts Hazard
To reduce the risk of injuring or amputating hands, fin-
gers, or other body parts, never place your hands,
body, or tools inside the air motor cover or near other
moving parts while the equipment is operating.

Troubleshooting
18 309239 Instructions - Parts List
Troubleshooting Chart
Troubleshooting ChartTroubleshooting Chart
Troubleshooting Chart
Problem Cause Solution
The system will not run or it stops while
running.
Air pressure or volume is too low. Increase the air pressure. Check the air
compressor.
Air line or an air valve is closed or
restricted.
Open or clean the air line or air valve as
required.
Fluid valves are closed. Open the fluid valves.
The air motor is worn or damaged. Service the air motor. See the Service
section.
Displacement pump is seized. Service the pump. See the displacement
pump manual 307944.
The fluids are not mixing properly. Fluid line filter is clogged. Clean the filter and replace the element, if
necessary.
Manifold is not operating correctly. Refer to manual 307400.
Check the ratio. Check or replace the pump.
Fluid hose is clogged. Replace the fluid hose.
The system speeds up or runs erratically. Fluid containers are empty. Check the containers often and keep
them filled.
Displacement pump parts are worn or
damaged.
Service the pump. See the displacement
pump manual 307944.
A squeaking or knocking noise is heard. Bearing(s) dry or worn. Lubricate the bearing(s) or replace them,
if required.
Continuous air exhaust from muffler. Motor piston o-ring (32) is worn or dam-
aged.
Inspect and replace the o-ring. See page
21.
Air cup (7) not seating properly or it is
damaged.
Inspect the air cup; reseat or replace it.
See page 24.
Continuous air exhaust from pilot valve
vent holes
Carriage spool u-cups (3c) are worn or
damaged.
Inspect the u-cups and replace if neces-
sary. See page 24.
Actuator valve pin o-rings (23) are worn
or damaged.
Inspect the o-rings and replace if neces-
sary. See page 22.
Air motor not shifting properly; erratic
operation/stalling.
Actuator valve pin o-rings (23, top or bot-
tom) are worn or damaged.
Inspect the o-rings and replace if neces-
sary. See page 22.
Actuator valve springs (16, top or bottom)
damaged.
Replace the springs. See page 22.
Carriage spool u–cups (3c) worn or dam-
aged (characterized by continuous air
leakage from actuator valve vents).
Inspect the u-cups and replace if neces-
sary. See page 24.
Clogged or obstructed valve porting. Clean porting.
Worn out valve housing (3). Replace the valve. See page 24.
Improper seating or damaged port or
valve housing o-rings.
Inspect o-ring and groove. Clean or
replace as necessary. See page 24.
Air leaking from air motor base vent hole. Worn or damaged low pressure u-cup
seal (19).
Inspect the u-cups and replace if neces-
sary. See page 21.
Fluid leaking from air motor base vent
hole.
Worn or damaged bearing (20). Inspect the bearing and replace if neces-
sary. See page 20.

309239 Instructions - Parts List
Service 19
Service
ServiceService
Service
Bearing and Pump Lubrication
Bearing and Pump LubricationBearing and Pump Lubrication
Bearing and Pump Lubrication
Insert one end of a nylon hose into the wet-cup. Hold
the other end of the hose up and pour the Throat Seal
Liquid through the hose and into the wet-cup until it is
full.
Lubricate the Mini-Cat proportioner’s main pivot beam
periodically with Graco Gear Reducer Oil.
Service instructions are in the manuals for the separate
components. Refer to the Troubleshooting Chart on
page 18 to help find the cause of the problem. The com-
ponent manual numbers are shown in the Solution col-
umn in the chart.
Air Lubrication
Air LubricationAir Lubrication
Air Lubrication
If your air supply is very dry, install air line lubricators
between the air regulators and pumps for automatic air
motor lubrication.
Proportioning Pump Removal
Proportioning Pump RemovalProportioning Pump Removal
Proportioning Pump Removal
1. Flush the entire system with a solvent compatible
with the fluid being pumped.
2. Disconnect the air line.
3. Follow the Pressure Relief Procedure on page 13.
4. Disconnect the fluid hose from the pump outlet.
5. Loosen the four adjusting knobs (pull up on the
knob to disengage the thread).
6. Remove the master pump stop pin.
7. Slide the pump(s) along the rail and remove the
pump(s) from the front of the Mini-Cat proportioner.
Proportioning Pump Installation
Proportioning Pump InstallationProportioning Pump Installation
Proportioning Pump Installation
1. With the four adjusting knobs loose, install the cata-
lyst pump assembly from the front of the Mini-Cat
proportioner. Slide the mounting plate between the
rails and the frame.
2. Install the master pump stop pin.
3. Install the master pump assembly and slide the
mounting plate until it meets the master pump stop
pin.
NOTE: The motor and master pump are located off cen-
ter of the mounting plate. When properly installed, the
mounting plate should be approximately flush with the
front of the frame, with the distance from the center of
the air motor to the front of the frame being 2-7/8” (73
mm). If the master pump is installed backwards, an off-
ratio condition will result.
4. Set the ratio. Refer to Setting the Ratio on page 12.
WARNING
Pressurized Equipment Hazard
To reduce the risk of serious injury, including splashing
in the eyes or on the skin or injury from moving parts,
follow the Pressure Relief Procedure on page 13
before checking or servicing the equipment and when-
ever you are instructed to relieve the pressure.

Service
20 309239 Instructions - Parts List
Air Motor Service
Air Motor ServiceAir Motor Service
Air Motor Service
Throat Packing Disassembly
1. Follow the procedure Proportioning Pump Removal
on page 19.
2. Remove the air motor cover (69). See Figure 5.
3. Disconnect the air motor (1) from the displacement
pump, as explained in displacement pump manual
307944.
4. Remove the three screws (29) holding the outlet
housing (18) to the bottom cylinder cap (4). Pull the
housing off the cap, being careful not to damage the
piston rod (17).
5. Remove the u-cup packing from the cap (4).
6. Remove the retaining ring (39) and the bearing (20)
from the outlet housing (18).
Throat Packing Reassembly
1. Lubricate the u-cup packing (19) and install it in the
bottom cylinder cap (4), with the lips facing up
toward the air motor (1). See Figure 5.
2. Install the bearing (20) and the retaining ring (39) in
the outlet housing (18).
3. Install the housing (18) on the cap (4).
4. Reconnect the air motor (1) to the displacement
pump, as explained in displacement pump manual
307944.
5. Install the air motor cover (69).
Figure 5 - Air Motor
8761C
2
70
69
1
17
19
20
39
4
18
29
1
1Lubricate
Lips face up, toward air motor (1)
2