Sherwin-Williams 820-206 User manual

Model 820–206 Model 820–208
03193A
04512A
OWNER’S MANUAL
820–204 Rev. K
Supercedes Rev. G, H & J
U.S. P A TENT NO. 4,323,741, 4,397,610
PATENTED 1983, CANADA
AND OTHER PATENTS PENDING
ELECTRIC, 120 VAC
ULTIMATE Plus + 600
Airless Paint Sprayer
3000 psi (210 bar) Maximum Working Pressure
Model 820–206 and 820–208, Series B
Basic sprayer only
The SHERWIN-WILLIAMS COMPANY, CLEVELAND, OHIO 44115
This manual contains important
warnings and information.
READ AND RETAIN FOR REFERENCE

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Table of Contents
Warnings 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Component Function and Identification 5. . . . . . . . . . . .
Setup 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Startup 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shutdown and Care 11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Flushing 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Repair Information 19. . . . . . . . . . . . . . . . . . . . .
Motor Test 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motor Brush 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Displacement Pump 22. . . . . . . . . . . . . . . . . . . . . . . . . . .
Motor 26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motor Control Board 27. . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Supply Cord 27. . . . . . . . . . . . . . . . . . . . . . . . . . . .
On/Off Switch 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive Housing, Connecting Rod, Crankshaft 28. . . . . .
Pressure Transducer 30. . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure T ransducer Seal 31. . . . . . . . . . . . . . . . . . . . . .
Suction Hose 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drain V alve 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Complete Sprayer Parts 34. . . . . . . . . . . . . . . . . . . . . . . .
Displacement Pump Parts 38. . . . . . . . . . . . . . . . . . . . . .
Technical Data 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions 39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accessories 39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sherwin-Williams W arranty 40. . . . . . . . . . . . . . . . . . . . .
Symbols
Warning Symbol
WARNING
his symbol alerts you to the possibility of serious
injury or death if you do not follow the instructions.
Caution Symbol
CAUTION
This symbol alerts you to the possibility of damage to
or destruction of equipment if you do not follow the
instructions.
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture or malfunction and result in serious injury .
D
This equipment is for professional use only .
D
Read all instruction manuals, tags, and labels before operating the equipment.
D Use the equipment only for its intended purpose. If you are not sure, call your distributor .
D
Do not alter or modify this equipment. Use only genuine Graco parts.
D Check equipment daily . Repair or replace worn or damaged parts immediately .
D Do not exceed the maximum working pressure of the lowest rated system component. Refer to
the T echnical Data on page 39 for the maximum working pressure of this equipment.
D Use fluids and solvents which are compatible with the equipment wetted parts. Refer to the Tech-
nical Data section of all equipment manuals. Read the fluid and solvent manufacturer ’ s warn -
ings.
D
Do not use hoses to pull equipment.
D Route hoses away from traffic areas, sharp edges, moving parts, and hot surfaces. Do not ex -
pose Graco hoses to temperatures above 82 _ C (180 _ F) or below –40 _ C (–40 _F).
D
Do not lift pressurized equipment.
D Comply with all applicable local, state, and national fire, electrical, and safety regulations.
WARNING
WARNING
INSTRUCTIONS

820-204 3
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.
D Know the specific hazards of the fluid you are using.
D Store hazardous fluid in an approved container . Dispose of hazardous fluid according to all local,
state and national guidelines.
D Always wear protective eyewear , gloves, clothing and respirator as recommended by the fluid
and solvent manufacturer .
INJECTION HAZARD
Spray from the gun, leaks or ruptured components can inject fluid into your body and cause ex -
tremely serious injury , including the need for amputation. Fluid splashed in the eyes or on the skin
can also cause serious injury .
D
Fluid injected into the skin is a serious injury . The injury may look like just a cut, but it is a serious
injury . Get immediate medical attention.
D Do not point the gun at anyone or at any part of the body .
D
Do not put your hand or fingers over the spray tip.
D Do not stop or deflect leaks with your hand, body , glove or rag.
D Do not “blow back” fluid; this is not an air spray system.
D Always have the tip guard and the trigger guard on the gun when spraying.
D Check the gun dif fuser operation weekly . Refer to the gun manual.
D Be sure the gun trigger safety operates before spraying.
D Lock the gun trigger safety when you stop spraying.
D Follow the Pressure Relief Procedure on page 8 if the spray tip clogs and before cleaning,
checking or servicing the equipment.
DT ighten all fluid connections before operating the equipment.
D Check the hoses, tubes, and couplings daily . Replace worn or damaged parts immediately . Do
not repair high pressure couplings; you must replace the entire hose.
D Fluid hoses must have spring guards on both ends, to help protect them from rupture caused by
kinks or bends near the couplings.
WARNING
WARNING

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WARNING
FIRE AND EXPLOSION HAZARD
Improper grounding, poor ventilation, open flames or sparks can cause a hazardous condition and re -
sult in a fire or explosion and serious injury .
D If there is any static sparking or you feel an electric shock while using this equipment, stop spray-
ing immediately . Do not use the equipment until you identify and correct the problem.
D Provide fresh air ventilation to avoid the buildup of flammable fumes from solvents or the fluid be -
ing sprayed.
D Keep the spray area free of debris, including solvent, rags, and gasoline.
D Electrically disconnect all equipment in the spray area.
D Extinguish all open flames or pilot lights in the spray area.
D Do not smoke in the spray area.
D Do not turn on or of f any light switch in the spray area while operating or if fumes are present.
D Do not operate a gasoline engine in the spray area.
MOVING P ARTS HAZARD
Moving parts can pinch or amputate your fingers.
D Keep clear of all moving parts when starting or operating the pump.
D Before servicing the equipment, follow the Pressure Relief Procedure on page 8 to prevent the
equipment from starting unexpectedly .
Liquids can be injected into the body by high pressure airless spray
or leaks – especially hose leaks.
Keep body clear of the nozzle. Never stop leaks with any part of the
body. Drain all pressure before removing parts.A void accidental trig -
gering
of gun by always setting safety latch when not spraying.
Never spray without a tip guard.
In case of accidental skin injection, seek immediate
“Surgical
T reatment”.
Failure to follow this warning can result in amputation or serious
injury.
FIRE AND
EXPLOSION HAZARD
SKIN INJECTION
HAZARD
READ AND UNDERSTAND ALL LABELS AND INSTRUCTION MANUALS BEFORE USE
Spray painting, flushing or cleaning equipment with flammable liq -
uids
in confined areas can result in fire or explosion.
Use outdoors or in extremely well ventilated areas. Ground equip -
ment,
hoses, containers and objects being sprayed.
Avoid all ignition sources such as static electricity from plastic drop
cloths, open flames such as pilot lights, hot objects such as ciga -
rettes,
arcs from connecting or disconnecting power cords or turn -
ing
light switches on and off.
Failure to follow this warning can result in death or serious injury .
NOTE: This is an example of the DANGER label on
your sprayer . This label is available in other
languages, free of charge. See page 39 to order .

 
Component Function and Identification
C
Fig. 1
E
F
DA
G
J
B
H
K
04512A
A Motor (Under shield shown) DC motor , 120 V ac, 15A, 1 phase
B Pressure Adjusting Knob Controls fluid outlet pressure
C ON/OFF Switch Power switch that controls 120 V ac main power to sprayer
D Drive Assembly T ransfers power from DC motor to the displacement pump
E Fluid Filter Filter of fluid between source and spray gun
F Fluid Outlet Spray gun operation is connected here
G Pail Hanger Container for fluid to be sprayed may be hung here
H Displacement Pump T ransfers fluid to be sprayed from source through spray gun
J Pressure Drain V alve Relieves fluid outlet pressure when open
R
K
Pressure Control Controls motor speed to maintain fluid outlet pressure at displacement
pump outlet. W orks with pressure adjusting knob.

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Setup
WARNING
If you supply your own hoses and spray gun, be
sure the hoses are electrically conductive, that the
gun has a tip guard, and that each part is rated for
at least 3000 psi (210 bar , 21 MPa) Working Pres -
sure
. This is to reduce the risk of serious injury
caused by static sparking, fluid injection or over–
pressurization and rupture of the hose or gun.
CAUTION
T o avoid damaging the pressure control, which
may result in poor equipment performance and
component damage, follow these precautions:
1. Always use a nylon spray hose at least 50 ft.
(15 m) long.
2. Never use a wire braid hose as it is too rigid to
act as a pulsation dampener .
3. Never install any shutof f device between the
pump and the hose. See Fig. 2.
4. Connect the hose and gun and screw it onto the
outlet nipple (F). Don’t use thread sealant, and
don’t install the spray tip yet!
5. Fill the wet–cup (L). Pry of f the wet–cup seal. Fill
the cup 1/3 full with Graco Throat Seal Liquid
(TSL) (68) supplied. Install the seal.
6. Check the electrical service. Be sure it is
120 V AC, 60 Hz, 15A (minimum). Use a properly
grounded outlet. Do not remove the third (ground -
ing) prong of the power supply cord, and do not
use an adapter .
Use a 3-wire (12 A WG recommended), 15A exten -
sion cord.
NOTE: Long extension cord lengths af fect sprayer
performance.
7.
Plug in the sprayer . Be sure the ON/OFF switch
(C) is OFF . Plug the cord into a grounded outlet at
least 20 ft. (6 m) away from the spray area.
FIRE AND EXPLOSION HAZARD
Proper electrical grounding is essential
to reduce the risk of fire or explosion
which can result in serious injury and
property damage. Also read FIRE OR
EXPLOSION HAZARD on page 4.
WARNING
continued on the next page
Fig.2
F
L
1
3
2
Do
not install any shutof f device here.
Shown in closed, or spray position.
Fill 1/3 full with TSL
2
1
Model 820–206 Shown
03193A
3

 
Setup
8. Flush the pump to remove the oil which was left
in to protect pump parts after factory testing. See
page 12.
9. Prepare the paint according to the manufacturer ’s
recommendations. Remove any paint skin. Stir the
paint to mix pigments. Strain the paint through a
fine nylon mesh bag (available at most paint deal -
ers) to remove particles that could clog the gun
filter or spray tip. This is an important step toward
trouble-free paint spraying.
How to use the gun safety latch
When engaged, the gun safety latch prevents the gun
from accidental triggering. See Fig. 3.
WARNING
If the gun still sprays when the gun safety latch is
engaged, adjust the gun. See manual 307–614,
supplied.
How to use the pressure drain valve
Use the pressure drain valve to relieve fluid pressure
from the pump and to help prime the pump. If the valve
senses an over-pressure condition, it opens automati -
cally to relieve fluid pressure. If this happens, stop
spraying immediately, shut of f and unplug the sprayer .
Determine the cause of the problem and correct it be -
fore operating the sprayer again. Refer also to the
T roubleshooting Guide, page 14. See Fig. 4.
How to use the pressure control
The pressure control controls the motor operation so
the sprayer maintains constant fluid pressure at the
pump outlet. T urn the pressure control knob fully coun -
terclockwise to obtain the minimum setting. T urn the
knob clockwise to increase pressure. See Fig. 5.
Engaged
Disengaged
Fig. 3
1
2
1
2
01020
Closed, or
spray position
Open, or
drain position
Fig. 4
1
2
1
2
02985A
Fig. 5 02986
+
–
1
1Rotate
to increase (+)
or decrease (–)
pressure

 
Setup
Pressure Relief Procedure
PRESSURIZED EQUIPMENT HAZARD
The equipment stays pressurized until
pressure is manually relieved. T o reduce
the risk of serious injury from pressur -
ized fluid, accidental spray from the gun or splash -
ing fluid, follow this procedure whenever you:
D Are instructed to relieve pressure
D Stop spraying
D Check, clean or service any system equipment
D Install or clean fluid nozzles
WARNING
1. Engage the gun safety latch.
2. T urn the ON/OFF switch of OFF .
3.
Unplug the power cord.
4. Disengage the gun safety latch. Hold a metal part
of the gun against a grounded metal pail and trig -
ger the gun into the pail to relieve pressure.
5. Engage the gun safety latch.
6. Open any fluid drain valves in the system. Leave
the drain valve open until you are ready to dis -
pense again.
How to use the RAC IV tip guard
WARNING
INJECTION HAZARD
Spray from the gun, leaks or ruptured
components can inject fluid into your
body and cause extremely serious injury ,
including the need for amputation. Fluid splashed in
the eyes or on the skin can also cause serious inju -
ry
. See also page 3.
The tip guard alerts you to the risk of injection and
helps prevent placing any part of the body close to the
spray tip. The tip guard also adjusts the vertical or hori -
zontal spray pattern. See page 10. The tip guard holds
a reversing spray tip. The tip is in the spraying position
when the tip handle points forward. See Fig. 6.
Clean the front of the tip frequently during the day’ s
operation. First, follow the Pressure Relief Proce -
dure
, left.
Fig. 6
Tip handle shown in
spraying position.
T urn handle 180 _,
trigger gun to clear clog
1
2
1 2
01023
How to remove a tip clog
7. Release the gun trigger . Engage the safety latch.
Rotate the RAC IV tip handle 180 _ . See Fig. 6.
8. Disengage the safety latch. T rigger the gun into a
pail or onto the ground to remove the clog.
9. Engage the safety latch. Rotate the tip handle to
the spraying position.
10. If the tip is still clogged, engage the safety latch,
shut of f and unplug the sprayer , and open the
pressure drain valve to relieve pressure. Clean the
spray tip as shown in manual 308–644, supplied.

 
Startup
03193A
Fig. 7
1Shown
in closed, or spray position.
M
N
J
C
2
2
Open, or drain position
1
B
+
–
Model 820–206 Shown
Use this procedure each time you start the sprayer to
help ensure the sprayer is ready to operate and that
you start it safely .
NOTE: If this is a first–time startup, flush the sprayer .
See page 12.
1. Open the pressure drain valve (J). See Fig. 7.
2. Don’t install the spray tip until the pump is
primed!
3. Put the suction hose or tube (M) into the paint.
If you are pumping from a 1 gallon (5 liter) pail,
push the drain hose (N) down below the top of the
pail to avoid splashing paint when the drain valve
is opened.
4. T urn the pressure knob (B) to the minimum
setting.
5. Disengage the gun safety latch.
See Fig. 3,
page 7.
CAUTION
T o reduce the risk of damage to the displace -
ment pump packings, never run the pump with -
out fluid in it for more than 30 seconds.
6. T o prime the pump, turn the sprayer ON/OFF
switch (C) ON. Slowly increase the pressure until
the sprayer starts. When fluid comes from the
pressure drain valve, close the valve.

10 820-204
Startup
T o reduce static sparking and splashing
when priming, be sure the spray tip is
not installed on the gun, and hold a
metal part of the gun firmly to the side of a
grounded metal pail.
WARNING
FIRE AND EXPLOSION HAZARD
7. T o prime the hose , lower the pressure to reduce
splashing. Holding the gun against the pail, trigger
the gun and slowly increase the pressure until the
pump starts. Keep the gun triggered until all air is
forced out of the system and the fluid flows freely
from the gun. Release the trigger and engage the
gun safety latch.
8. Check all fluid connections for leaks . Relieve
pressure before tightening any connections.
9. Install the spray tip. Engage the gun safety latch
first! See manual 308–644 for how to install the tip.
10. Adjust the spray pattern
a.
Increase the pressure just until spray from the
gun is completely atomized. T o avoid exces -
sive overspray and fogging, and to extend tip
and sprayer life, always use the lowest pres -
sure needed to get the desired results.
b. If more coverage is needed, use a larger tip
rather than increasing the pressure.
c. T est the spray pattern. T o adjust the direction
of the spray pattern, engage the gun safety
latch and loosen the retaining nut (B). Position
the tip guard horizontally for a horizontal pat -
tern or vertically for a vertical pattern. Hold the
tip guard in place while tightening the retaining
nut. See Fig. 8.
NOTE: Spray patterns will change as tips wear .
Change the spray tip if adjusting the pressure will not
improve the spray pattern.
For a horizontal
spray pattern
For a vertical
spray pattern
Fig. 8
1
2
2
1
B
01025

820-204 11
Shutdown and Care
WARNING
INJECTION HAZARD
T o reduce the risk of serious injury ,
whenever you are instructed to relieve
pressure, follow the Pressure Relief
Procedure on page 8.
1. Relieve pressure.
2. Check the packing nut/wet-cup daily. Keep the
wet-cup 1/3 full of TSL at all times to help prevent
fluid buildup on the piston rod and premature wear
of packings.
3. Tighten the packing nut/wet-cup just enough
to stop leakage.
Over-tightening causes binding
and excessive packing wear . Use a round punch
or brass rod and a light hammer to adjust the nut.
See Fig. 9.
4. Clean the gun’s fluid filter often and whenever
the gun is stored. Relieve pressure first. Refer to
manual 307–614.
5. Lubricate the bearing housing after every 100
hours of operation. Remove the front cover . Apply
several drops of SAE 10 non-detergent oil in the
bearing housing cavity (B). See Fig. 10.
6. Flush the sprayer at the end of each work day
and fill it with mineral spirits to help prevent pump
corrosion and freezing. See page 12.
CAUTION
T o prevent pump corrosion, and to reduce the
chance of fluid freezing in the pump in cold
weather , never leave water or any type of paint in
the sprayer when it is not in use. Freezing can seri
-
ously damage the sprayer or result in a loss of
pressure or stalling.
7. For very short shutoff periods, leave the suction
hose in the paint, relieve pressure, and clean the
spray tip.
8. Coil the hose when storing it, even for overnight,
to help protect the hose from kinking, abrasion,
coupling damage, etc.
INJECTION HAZARD
See the warning section INJECTION
HAZARD on page 3 for information on
the hazard of using damaged hoses.
WARNING
02985A
Turn packing
nut clockwise to
tighten
Fig. 9
1
1
03198A
Fig. 10
B

12 820-204
Flushing
When to flush
Determine the material you are going to pump from
Column 1, then flush with the material indicated in
Column 2. Depending on what you plan to do next,
follow the recommendations in one of the next three
columns.
CAUTION
NEVER leave water or water-based fluids in the
sprayer if there is a chance it could freeze. Push
the water out with mineral spirits. Frozen fluid in
the sprayer prevents it from starting and may
cause serious damage.
Column 1 Column 2 Column 3 Column 4 Column 5
If you are going to: BFlush with: B Prime with: BClean with: BStore unit with:
B
Spray latex paint W arm, soapy water ,
then clean water
Latex-base paint W arm soapy water ,
then clean water
Mineral spirits
Spray oil paint Mineral spirits Oil–base paint Mineral spirits Mineral spirits
Change latex to oil paint W arm, soapy water ,
then clean water
Mineral spirits Mineral spirits Mineral spirits
Change oil to latex paint Mineral spirits,
soapy water , and
clean water .
Latex W arm, soapy water ,
then clean water
Mineral spirits
Change colors, same base Compatible solvent
such as water or
mineral spirits
How to flush WARNING
INJECTION HAZARD
T o reduce the risk of serious injury ,
whenever you are instructed to relieve
pressure, follow the Pressure Relief
Procedure on page 8.
1. Relieve pressure.
2. Remove the spray tip and clean it separately . If
you are changing from water-based to oil-based
paints or solvents, be sure that the tip is cleaned
thoroughly.
3.
Remove the filter screen and then reinstall the
bowl, hand tight, without the screen. Clean the
screen separately . See manual 308–249.
4. Pour one-half gallon (2 liters) of compatible solvent
into a grounded metal flushing pail. Put the suction
hose in the pail.
5. Open the pressure drain valve. See Fig.1 1.
6. To save the paint still in the pump and hose,
follow Step 7, except put the drain hose in the
paint pail. When solvent appears, close the drain
valve. Put the drain hose in the flushing pail. T rig-
ger the gun into the paint pail. When solvent ap -
pears, release the trigger . Continue with Step 7.

820-204 13
Flushing
T o reduce static sparking and splashing,
always remove the spray tip from the
gun, and hold a metal part of the gun
firmly to the side of a grounded metal pail when
flushing.
WARNING
FIRE AND EXPLOSION HAZARD
7. Lower the pressure setting. T urn on the sprayer .
Maintaining metal-to-metal contact, trigger the gun
into the flushing pail. Slowly increase the sprayer
pressure just until the pump starts. Keep the gun
triggered until the solvent flows freely from the
gun. Circulate the solvent to thoroughly clean the
sprayer . Release the gun trigger . Engage the gun
safety latch.
8. Open the drain valve and circulate the solvent
through the drain hose to thoroughly clean it.
Close the drain valve.
9. Remove the suction hose from the pail. Disengage
the gun safety latch. T rigger the gun and run the
pump a few seconds to push air into the hose. Do
not run the pump dry for more than 30 seconds to
avoid damaging the pump packings! Relieve pres -
sure.
10.
Reinstall the clean filter screen.
11. Remove and clean the inlet strainer . Wipe paint of f
the suction hose and drain hose.
12. Leave the drain valve open until you use the
sprayer again.
02987A
Open or
drain position
Fig. 1 1
1
1
21

14 820-204
Troubleshooting
WARNING
PRESSURIZED EQUIPMENT HAZARD
T o reduce the risk of serious injury ,
always follow the Pressure Relief
Procedure on page 8 before checking
or repairing any part of the sprayer .
CAUTION
Thaw sprayer if water or water-based paint has
frozen in it, due to exposure to low temperatures,
by placing it in a warm area. Do not try to start
sprayer until it has thawed completely or damage
to motor and/or control board may occur . If paint
hardened (dried) in sprayer , the pump packings
and/or pressure transducer must be replaced. See
page 22 (pump) or 30 (pressure transducer).
Check everything in the troubleshooting tables before disassembling the sprayer .
Basic Problem Solving
TYPE OF
PROBLEM WHA
T T O CHECK
If check is OK, go to next check
WHA T T O DO
When check is not OK, refer to this column
Fluid Pressure 1. Check pressure transducer knob setting. The
pump won’t develop much pressure if it is at mini -
mum setting (fully counterclockwise).
1. Slowly increase pressure setting to see if
motor starts.
2. Check for a clogged spray tip or fluid filter , if used.
See page 8.
2. If tip is still clogged, relieve pressure;
refer to separate gun or tip instruction
manual for tip cleaning. Clean or replace
filter element. See manual 308–249.
Mechanical 1. Check for frozen or hardened paint in pump (20).
Using a screwdriver , carefully try to rotate fan at
back of motor by hand. See page 26.
1. Thaw . After thawing, plug in sprayer and
turn it on. Slowly increase pressure set -
ting to see if motor starts. If it doesn’t
start, see CAUTION above.
2. Check pump connecting rod pin (17). It must be
completely pushed into connecting rod (15), and
retaining spring (18) must be firmly in connecting
rod groove. See Fig. 18, page 23.
2. Push pin into place and secure with
spring retainer .
3. Check for motor damage. Remove drive housing
assembly (1 1). See page 28. T ry to rotate motor
fan by hand.
3. Replace motor (4) if fan won’t turn. See
page 26.
Electrical 1. Check electrical supply with volt meter . Meter
should read 105–125 V AC. 1.
Reset building circuit breaker; replace
building fuse. T ry another outlet.
2. Check extension cord for visible damage. Use a
voltmeter or test lamp at extension cord outlet to
check.
2. Replace extension cord.
3. Check sprayer power supply cord (50) for visible
damage such as broken insulation or wires.
3. Replace power supply cord. See page
27.

820-204 15
Basic Problem Solving
TYPE OF
PROBLEM WHA
T T O CHECK
If check is OK, go to next check
WHA T T O DO
When check is not OK, refer to this column
Electrical
(continued)
4. Check motor brushes for the following:
a. Loose terminal screws.
b. Broken or misaligned brush springs.
c. Brushes binding in holders.
d. Broken leads.
e. W orn brushes.
f. Brush leads snagged on spring clip.
NOTE: The brushes do not wear at same
rate on both sides of motor . Check both
brushes.
4. Refer to page 21.
a. Tighten.
b.
Replace broken spring and/or align
spring with brush
c. Clean brush holders. Remove carbon
with small cleaning brush. Align brush
leads with slot in brush holder to as -
sure free vertical brush movement.
d. Replace brushes
e. Replace brushes if less than 0.4”
(10 mm) long.
f. Correctly route the wires.
See page 21.
5. Check motor armature commutator for burn spots,
gouges and extreme roughness. Remove motor
cover and brush inspection plates to check. See
page 21.
5. Remove motor and have motor shop
resurface commutator if possible. See
page 26.
6. Check motor armature for shorts using armature
tester (growler) or perform motor test. See page
20.
6. Replace motor . See page 26.
7. Check leads from pressure transducer and motor
to motor control board (47) to be sure they are se -
curely fastened and properly mated.
7. Replace loose terminals; crimp to leads.
Be sure male terminal blades are straight
and firmly connected to mating part.
8. Check motor control board (47) by substituting with
a good board.
CAUTION: Do not perform this check until motor
armature is determined to be good. A bad motor
armature can burn out a good board.
8. Replace board. See page 27.
9. Check power supply cord (50). Disconnect black
and white power cord terminals; connect volt
meter to these leads. Plug in sprayer . Meter should
read 105–125 V AC. Unplug sprayer .
9. Replace power supply cord. See page
27.
10.Check ON/OFF switch (52). Disconnect the “L”
wire between motor control board (47) and switch
and connect volt meter between exposed terminal
switch and power cord’ s white wire. Plug in
sprayer and turn ON . Meter should read 105–125
VAC. T urn of f and unplug sprayer .
10. Replace ON/OFF switch. See page 27.
11. Check motor thermal cutout switch. Connect ohm -
meter between motor ’ s red leads. Meter should
read 1 ohm maximum.
11. Allow motor to cool. Correct cause of
overheating. If switch remains open after
motor cools, replace motor .
12. Check the transducer (29) by replacing it with a
new one.
12.Replace pressure transducer . See page
30.
13. Check pressure adjustment potentiometer (64) by
replacing it with a new one.

16 820-204
Intermediate Problem Solving
TYPE OF
PROBLEM WHA
T T O CHECK
If check is OK, go to next check
WHA T T O DO
When check is not OK refer to this column
Low Output 1. Check for worn spray tip. 1. Follow Pressure Relief Procedure
W arning on page 8, then replace tip.
See your separate gun or tip manual.
2. Be sure pump does not continue to stroke
when gun trigger is released. Plug in and
turn on sprayer . Prime with paint. T rigger gun mo -
mentarily
, then release and engage safety latch.
Relieve pressure, turn of f and unplug sprayer .
2. Service pump. See page 23.
3. Release gun trigger . Observe resting position of
pump rod (107).
3. If pump consistently comes to rest
with rod (107) fully extended, the piston
packings and/or piston valve may be
worn. Service the pump. See page 23.
4. Check electrical supply with volt meter . Meter
should read 105–125 V AC. 4.
Reset building circuit breaker; replace
building fuse. Repair electrical outlet or
try another outlet.
5. Check extension cord size and length. 5. Replace with a correct, grounded exten -
sion cord. Note that long lengths and/or
smaller gauges reduce performance.
6. Check motor brushes. See Electrical – What T o
Check, item 4, on page 15.
6. See page .

820-204 17
Intermediate Problem Solving
TYPE OF
PROBLEM WHA
T T O CHECK
If check is OK, go to next check
WHA T T O DO
When check is not OK, refer to this column
Low Output
(continued)
7. Check motor control board (47) by substituting with
a good board.
CAUTION: Do not perform this check until motor
armature is determined to be good. A bad motor
armature can burn out a good board.
7. Replace board. See page 27.
8. Check motor armature for shorts by using an arma -
ture tester (growler) or perform motor test. See
page 20.
8. Replace motor . See page 26
.
Drain V alve Leaks 1. Check drain valve for correct torque and/or worn
parts. Check for debris trapped on seat.
1. T ighten to 185 in–lb (21 N.m). Clean
valve and replace with new gasket (42a)
and sealant (42e). See page 33.
No Output: Motor
Runs And Pump
Strokes
1. Check paint supply . 1. Refill and reprime pump.
2. Check for clogged intake strainer . 2. Remove and clean, then reinstall.
3. Check for loose suction tube or fittings. See
page 32.
3. T ighten; use thread sealant on
npt threads of inlet tube (38). Check for
damaged o–ring (27).
4. Check to see if intake valve ball and piston ball are
seating properly . See page 23.
4. Remove intake valve and clean. Check
ball and seat for nicks; replace as need -
ed. See page 23. Strain paint before us -
ing to remove particles that could clog
pump.
5. Check for leaking around throat packing nut
which may indicate worn or damaged packings.
See page 23.
5. Replace packings. See page 23. Also
check piston valve seat for hardened
paint or nicks and replace if necessary .
T ighten packing nut/wet-cup.
6. Release gun trigger . Observe resting position of
pump rod (107).
6. If pump consistently comes to rest
with rod (107) fully extended, the piston
packings and/or piston valve may be
worn. Service the pump. See page 23.
No Output: Motor
Runs But Pump
Does Not Stroke
1. Check displacement pump connecting rod pin (17).
See Fig. 18, page 23.
1. Replace pin if missing. Be sure retainer
spring (18) is fully in groove all around
connecting rod.
2. Check connecting rod assembly (15) for damage.
See page 28.
2. Replace connecting rod assembly . See
page 28.
3. Be sure crank in drive housing rotates; plug in
sprayer and turn on briefly to check. T urn of f and
unplug sprayer . See page 28.
3. Check drive housing assembly for dam -
age and replace if necessary . See page
28.
Spray Pattern
Variations 1.
Spray tip worn beyond sprayer pressure capability . 1. Replace spray tip.
NOTE: A smaller size tip will provide
longer life.
2. Check motor control board by replacing it with a
new one.
2. Replace board. See page 27.
3. Check pressure adjustment potentiometer (64) by
replacing it with a new one.
3. Replace pressure transducer . See page
30.

18 820-204
Intermediate Problem Solving
TYPE OF
PROBLEM WHA
T T O CHECK
If check is OK, go to next check
WHA T T O DO
When check is not OK, refer to this column
Spray Pattern
Variations
(continued)
4. Check pressure adjustment potentiometer (64) by
replacing it with a new one.
(continued)
5. Check Low Output section, page 16.
Motor Is Hot and
Runs Intermittently
1. Determine if sprayer was operated at high pressure
with small tips, which causes excessive heat build
up.
1. Decrease pressure setting or increase tip
size.
2. Be sure ambient temperature where sprayer is lo -
cated is no more than 90 _ F (32 _C) and sprayer is
not located in direct sun.
2. Move sprayer to shaded, cooler area if
possible.
3. Check motor. 3. Replace motor . See page 26.
Building Circuit
Breaker Opens As
Soon As Sprayer
Switch Is Turned
O
1. Check all electrical wiring for damaged insulation,
and all terminals for loose fit or damage.
Also check wires between pressure transducer
and motor . See page 26.
1. Repair or replace any damaged wiring or
terminals. Securely reconnect all wires.
Switch Is Turned
On. 2.
Check for missing motor brush inspection plate
gasket (see page 21), bent terminal forks or other
metal to metal contact points which could cause a
short.
2. Correct faulty conditions.
3. Check motor armature for shorts. Use an
armature tester (growler) or perform motor test.
See page 18. Inspect windings for burns.
3. Replace motor . See page 26.
4. Check motor control board (47) by substituting with
a good board.
CAUTION: Do not perform this check until motor
armature is determined to be good. A bad motor
armature can burn out a good board.
4. Replace board. See page 27.
Circuit breaker
opens after sprayer
operates for 5 to 10
minutes.
1. Check ‘Basic Problems – Electrical’ on page 14.
Building circuit
breaker opens as
soon as sprayer is
plugged into outlet
and sprayer is NOT
turned on.
1. Check ON/OFF switch (52). Be sure sprayer is
unplugged! Disconnect wires from switch. Check
switch with ohmmeter . The reading should be
infinity with ON/OFF switch OFF , and zero with
switch ON.
CAUTION:
A short in motor circuit can damage
switch and or motor control board (47).
1. Replace ON/OFF switch. See page 27.
2. Check for damaged or pinched wires in junction
box (59).
2. Replace damaged parts.
Unit will not run on
generator but does
run on AC power
1. Check the generator ’s “peak” voltage. This sprayer
will not run if the peak voltage is above 190V or
below 100V .
1. Use AC power or a dif ferent generator .

820-204 19
General Repair Information
WARNING
INJECTION HAZARD
T o reduce the risk of serious injury ,
whenever you are instructed to relieve
pressure, follow the Pressure Relief
Procedure on page 8.
Tool List
These service tools are required.
1/4” Allen wrench: filter plug
3/8” Allen wrench: pump manifold
3/16” Allen wrench: gear housing, legs, handle
5/64” Allen wrench: pressure adjustment knob
#1 Phillips  screwdriver: junction box, front cover ,
motor shield
3/8” socket wrench: motor mount
5/8” socket wrench: drain valve, on/off switch boot,
piston
5/8” open end wrench: outlet fittings
13/16” socket wrench: drain valve
1-1/4” socket wrench: pump inlet valve
1/2” open end wrench: pump rod
1 1/16” open end wrench: piston jam nut
15/16” open end wrench: flats of inlet tube
1-3/4” open end wrench: pump jam nut
5/64” drive pin: drain valve pin
3” needle nose pliers: wiring, on/off switch
Hammer & punch: packing nut
T orque wrenches: various fasteners
Pipe wrench: suction tube
CAUTION
T o reduce the risk of a pressure transducer mal -
function, properly mate connectors and never pull
on a wire to disconnect it.
1. When disconnecting wires , use needle nose
pliers to separate mating connectors.
2. When reconnecting wires , center the flat blade
of the male connector in the blade of the female
connector.
3.
Route wires carefully and avoid pinching any
wires between covers.
CAUTION
Improper wire routing can result in poor sprayer
performance or damage to the pressure trans -
ducer.
4.
Keep all screws, nuts, washers, gaskets, and
electrical fittings removed during repair proce -
dures.
5. T
est your repair before regular operation to be
sure the problem is corrected.
6. If the sprayer does not operate properly , verify
that everything was done correctly. Also refer to
the T roubleshooting Guide, page 14, to help iden -
tify other possible problems and solutions.
WARNING
MOVING P ARTS HAZARD
T o reduce the risk of serious injury , in -
cluding electric shock, DO NOT touch
any moving parts or electrical parts with
your fingers or a tool while inspecting the sprayer .
Shut of f the sprayer and unplug it as soon as you
complete the inspection.
Reinstall all covers, gaskets, screws and washers
before operating the sprayer .
WARNING
FIRE HAZARD
During operation, the motor and drive
housing become very hot and could burn
your skin if touched. Flammable materi -
als spilled on the hot, bare motor could cause a fire
or explosion.

 
Motor T est
WARNING
INJECTION HAZARD
T o reduce the risk of serious injury ,
always follow the Pressure Relief
Procedure on page 8 before doing this
procedure. Unplug the sprayer!
For checking armature, motor winding and brush elec -
trical continuity .
Setup
Remove the drive housing. See page 28. This is to
ensure that any resistance you notice in the armature
test is due to the motor and not to worn gears in the
drive housing.
Remove the motor brush inspection covers (A). See
Fig. 12.
Remove the screws (56,75). Lower the control board
(47). Disconnect the two leads (C) from the motor to
the board. See Fig.13.
A
B
Fig. 12
02991
Armature Short Circuit Test
Remove the fan cover (B). See Fig.12.
Spin the motor fan by hand. If there are no shorts, the
motor will coast two or three revolutions before coming
to a complete stop. If the motor does not spin freely
,
the armature is shorted and the motor must be re -
placed. See page 26.
Armature, Brushes, and Motor Wiring
Open Circuit Test (Continuity)
Connect the two black motor leads (C) together with a
test lead. T urn the motor fan by hand at about two
revolutions per second. See Fig. 13.
Fig. 13
C
MOT OR (4)
47
9
49
52
50
D
P
03000
2964
G
When turning the fan on a DC motor, normally you
sense an even, pulsing resistance. If there is irregular
turning resistance, or no turning resistance, check and
repair the following as needed: broken brush springs,
brush leads, motor leads; loose brush terminal screws
or motor lead terminals; worn brushes. See page 21.
If there is still uneven or no turning resistance, replace
the motor . See page 26.