Graco 231-315 Series Operation manual

308–304
Rev . E
Supersedes D
and PCN E
First choice when
quality counts. 
INSTRUCTIONS-PARTS LIST
INSTRUCTIONS
This manual contains important
warnings and information.
READ AND KEEP FOR REFERENCE.
220/240 V AC
ULTRA 500
AIRLESS P AINT SPRA YER
19.5 MPa, 195 bar (2750 psi) Maximum Working Pressure
Model 231–315 Series B
Complete sprayer on Lo-boy cart with hose,
gun, RAC IV  DripLess  T ip Guard
and SwitchT ip
GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441
http://www.graco.com
COPYRIGHT
1995, GRACO INC.
Graco Inc. is registered to I.S. EN ISO 9001



Table of Contents
Warnings 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setup 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Startup 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shutdown and Care 10. . . . . . . . . . . . . . . . . . . . . . . . . . .
Flushing 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spin Test 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Repair Information 18. . . . . . . . . . . . . . . . . . . . .
Motor Brush Replacement 19. . . . . . . . . . . . . . . . . . . . .
Power Supply Cord Replacement 20. . . . . . . . . . . . . . .
On/Off Switch Replacement 21. . . . . . . . . . . . . . . . . . . .
Pressure Control Replacement 22. . . . . . . . . . . . . . . . .
Filter Board Replacement 23. . . . . . . . . . . . . . . . . . . . . .
Drive Housing, Connecting Rod, and Crankshaft
Replacement 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motor Replacement 26. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Displacement Pump Repair 28. . . . . . . . . . . . . . . . . . . . .
Parts Drawing – Loboy Sprayer 31. . . . . . . . . . . . . . . . .
Parts List – Loboy Sprayer 32. . . . . . . . . . . . . . . . . . . . .
Parts Drawing and List – Displacement Pump 33. . . . .
Parts Drawing – Pressure Control 34. . . . . . . . . . . . . . .
Parts List – Pressure Control 34. . . . . . . . . . . . . . . . . . .
Wiring Diagram 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Data 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions 35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Graco W arranty and Disclaimers 36. . . . . . . . . . . .
Graco Phone Number 36. . . . . . . . . . . . . . . . . . . . . . . . . .
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.
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
.

If there is any static sparking or you feel an electric shock while using this equipment, stop
spraying 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 sprayed.
 Keep the spray area free of debris, including solvent, rags, and gasoline.
 Electrically disconnect all equipment in the spray area.
 Extinguish all open flames or pilot lights in the spray area.
 Do not smoke in the spray area.
 Do not turn on or of f any light switch in the spray area while operating or if fumes are present.
 Do not operate a gasoline engine in the spray area.
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 Graco T echnical Assis -
tance at 1–800–543–0339.
 Do not alter or modify this equipment.
 Check equipment daily . Repair or replace worn or damaged parts immediately .
 Do not exceed the maximum working pressure of the lowest rated system component. Refer to
the T echnical Data on page 35 for the maximum working pressure of this equipment.
 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.

Do not use 1,1,1–trichloroethane, methylene chloride, other halogenated hydrocarbon solvents or
fluids containing such solvents in pressurized aluminum equipment. Such use could result in a
chemical reaction, with the possibility of explosion.
 Do not use hoses to pull equipment.
 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).

Do not lift pressurized equipment.
 Comply with all applicable local, state, and national fire, electrical, and safety regulations.
W ear hearing protection when operating this equipment.
WARNING
WARNING
INSTRUCTIONS
MOVING P ARTS HAZARD
Moving parts, such as the air motor piston, can pinch or amputate your fingers.
 Keep clear of all moving parts when starting or operating the pump.
 Before servicing the equipment, follow the Pressure Relief Procedure on page 12 to prevent the
equipment from starting unexpectedly
.
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.
 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 .
 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.
 Do not point the gun at anyone or at any part of the body .

Do not put your hand or fingers over the spray tip.
 Do not stop or deflect leaks with your hand, body , glove or rag.
 Do not “blow back” fluid; this is not an air spray system.
 Always have the tip guard and the trigger guard on the gun when spraying.
 Check the gun dif fuser operation weekly . Refer to the gun manual.
 Be sure the gun trigger safety operates before spraying.
 Lock the gun trigger safety when you stop spraying.
 Follow the Pressure Relief Procedure on page 12 if the spray tip clogs and before cleaning,
checking or servicing the equipment.
T ighten all fluid connections before operating the equipment.
 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.
 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
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.

5
308-304
05203
K
Fig. 1
J
S
P
E
D
A
C
T
L
R
M
N
B
H
Major Components
0137A
AMotor DC motor , 220/240 Vac, 50 Hz, 7A, 1 phase
B Pressure Adjusting Knob Controls fluid outlet pressure
C ON/OFF Switch Power switch that controls 220/240 V ac main power to sprayer
D Drive Assembly T ransfers power from DC motor to the displacement pump
E Fluid Filter Final filter of fluid between source and spray gun
H Displacement Pump T ransfers fluid to be sprayed from source through spray gun
J 50 ft (15 m) Main Hose 1/4 in. ID, grounded, nylon hose with spring guards on both ends
K RAC IV T ip Guard Reverse-A-Clean (RAC) tip guard reduces risk of injection injury
L Contractor Gun High pressure spray gun with gun safety latch
M RAC IV Switch T ip RAC switch tip uses high pressure fluid to remove clogs from spray
tip without removing tip from spray gun
N 3 ft (0.9 m) Hose 3/16 in. ID, grounded, nylon hose used between 50 ft hose and
spray gun to allow more flexibility when spraying
P Primary Fluid Outlet Single spray gun operation is connected here
R Pressure Drain V alve Relieves fluid outlet pressure when open
S Pressure Control Controls motor speed to maintain fluid outlet pressure at displace -
ment pump oulet. W orks with pressure adjusting knob.
T Spray Gun Safety Latch Gun safety latch inhibits accidental triggering of spray gun

6308-304
Setup
WARNING
To reduce the risk of serious injury from static
sparking, injection, or over pressurization and
rupture
of the hose or gun, all hoses must be electri -
cally conductive, the gun must have a tip guard, and
each part must be rated for at least 21.0 MPa, 210
bar
(3000 psi) Maximum W orking Pressure.
T o avoid damaging the pressure control, which may
result in poor equipment performance and compo-
nent
damage, follow these precautions:
1. Always use grounded, flexible 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 filter
and the main hose. See Fig. 2.
4. Always use the main filter outlet for one gun op -
eration.
Never plug this outlet.
CAUTION
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. Read the warning sec -
tion FIRE OR EXPLOSION HAZARD on
page 2 for more detailed grounding
instructions.
WARNING
NOTE: See Fig. 2 while doing the setup.
1. Fill the packing nut/wet-cup 1/3 full with Graco
Throat Seal Liquid (TSL), supplied.
2. Connect the gun, 0.9 m (3 ft) hose and 15.1 m
(50 ft) hose.
Screw the assembly onto the outlet
nipple. Don’t use thread sealant and don’t install
the spray tip yet!
3. Check the Electrical Service.
a. Electrical requirements: 220/240 V AC, 50 Hz,
7A (minimum).
b. Use
a grounded electrical outlet located at least
6 m (20 ft) from the spray area.
b. Do not remove the grounding prong of the power
supply cord and do not use an adapter .
c. Extension cord specifications: 10A, 3-wire,
grounding type. (Long lengths reduce sprayer
performance.)
4. Plug
in the sprayer. T urn the ON/OFF switch
OFF . Plug the cord into a grounded electrical out -
let.
5. Flush the pump
to remove the oil left in to protect
pump parts after factory testing. See Flushing
on page 1 1.
6.
Prepare the paint according to the manufacturer ’s
recommendations. Remove any paint skin. Stir the
paint thoroughly . Strain the paint through a fine
nylon mesh bag (available at most paint dealers)
to remove particles that could clog the filter or
spray tip. This is an important step for trouble-free
paint spraying.

7
308-304
Setup
05204
ON/OFF SWITCH
1/4 npsm(m) FLUID OUTLET NIPPLE
DO NOT INST ALL ANY SHUT OFF
DEVICE HERE
PRESSURE ADJUSTING KNOB
PRESSURE
DRAIN
VALVE
P ACKING NUT/ WET–CUP
FILL 1/3 FULL WITH TSL
Fig. 2


Startup
Use this procedure each time you start the sprayer to
help
ensure the sprayer is ready to operate and that you
start it safely .
WARNING
INJECTION HAZARD
T o reduce the risk of serious injury ,
follow the illustrated Pressure Relief
Procedure warning on page 12 when -
ever you are instructed to relieve pressure.
NOTE: Flush the sprayer if this is a first-time startup.
See page 1 1.
NOTE:
See Fig. 4 except where noted.
1. Put the suction tube into the paint container.
2. Turn the pressure adjusting knob fully coun-
terclockwise to zero pressure.
3. Plug in the sprayer .
CAUTION
Do not run the pump without fluid in it for more than
30 seconds to avoid damage to the displacement
pump
packings.
T o reduce the risk of static sparking and
splashing when flushing, 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.
WARNING
FIRE AND EXPLOSION HAZARD
4. Prime the pump .
a. Open the pressure drain valve (handle in down -
ward position). Turn the ON/OFF switch to ON.
Slowly turn the pressure adjusting knob clock-
wise until the sprayer starts. When fluid comes
from the drain hose, close the valve (handle in
forward
position).
b. Disengage the gun safety latch. See Fig. 3.
Following the warning, above, trigger the gun
until all air is forced out of the system and the
paint
flows freely from the gun.
c. Release the trigger . Engage the gun safety latch.
5. Check all fluid connections for leaks . Relieve
the fluid pressure before tightening connections.
6. Install the spray tip and tip guard. Engage the
gun safety latch. See Fig. 3. Install the spray tip
according to the instructions supplied with it.
7. Adjust the spray pattern.
a. Increase the pressure just until spray from the
gun is completely atomized. Use the lowest
pressure
needed to get the desired results. This
reduces overspray and fogging, decreases tip
wear
and extends the life of the sprayer .
b. If more coverage is needed, use a larger tip
rather
than increasing the pressure.
c. Test the spray pattern. T o adjust the pattern,
engage
the gun safety latch, loosen the retaining
nut. Position the tip guard horizontally for a hori -
zontal pattern or vertically for a vertical pattern.
Then tighten the retaining nut.
01020A
0137
GUN SAFETY
LA TCH SHOWN
ENGAGED
GUN SAFETY LA TCH
SHOWN DISENGAGED
Fig. 3
ON/OFF SWITCH
OUTLET NIPPLE
PRESSURE ADJUSTING KNOB
PRESSURE
DRAIN
VALVE
DRAIN HOSE
Fig. 4
05205

9
308-304
Startup
Cleaning a Clogged Tip
WARNING
FLUID INJECTION HAZARD
T o reduce the risk of serious injury ,
follow the illustrated Pressure Relief
Procedure warning on page 12 when -
ever you are instructed to relieve pressure.
1. Clean the front of the tip frequently during the day’s
operation. First, relieve pressure.
2. If the spray tip does clog, release the gun trigger , en -
gage the gun safety latch, and rotate the RAC IV
handle
180  . See Fig. 5.
3. Disengage the gun safety latch and trigger the gun
into a waste container. Engage the gun safety latch
again.
4.
Return the handle to the original position, disengage
the gun safety latch, and resume spraying.
5. If the tip is still clogged, engage the gun safety latch,
shut of f and unplug the sprayer , and open the pres-
sure
drain valve to relieve pressure. Clean the spray
tip as shown on the RAC IV package.
0137A
GUN SAFETY
LATCH
SHOWN
ENGAGED
TIP GUARD HANDLE
SHOWN IN SPRA YING
POSITION
TURN HANDLE 180 ,
DISENGAGE SAFETY
LATCH AND TRIGGER
GUN TO CLEAR CLOG
Fig. 5

10 308-304
Shutdown and Care
WARNING
FLUID INJECTION HAZARD
T o reduce the risk of serious injury ,
follow the illustrated Pressure Relief
Procedure warning on page 12 when -
ever you are instructed to relieve pressure.
1. Check the packing nut/wet-cup daily . First relieve
pressure. 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.
Tighten the packing nut just enough to stop leakage.
Over tightening causes binding and excessive pack -
ing wear. Use a round punch or brass rod and light
hammer
to adjust the nut. Refer to Fig. 6.
2. Clean the fluid filter often and whenever the spray -
er
is stored. Follow the Flushing Guidelines on page
11 or refer to manual 307–273, supplied, for the
cleaning
procedure.
3. Lubricate the bearing housing after every 100
hours of operation. First relieve pressure. Remove
the front cover. Fill the bearing housing cavity with
SAE
10 non-detergent oil. See Fig. 7.
4. For very short shutoff periods, leave the suction
tube in the paint, relieve pressure, and clean the
spray
tip.
5. Flush the sprayer at the end of each work day and
fill it with mineral spirits to help prevent pump corro -
sion
and freezing. See page 1 1.
To
prevent pump corrosion, never leave water or any
type of paint in the sprayer when it is not in use. Pump
water or paint out with mineral spirits.
CAUTION
6. Coil the hose and hang it on the hose rack when
storing
it, even for overnight, to help protect the hose
from kinking, abrasion, coupling damage, etc.
PACKING NUT/
WET–CUP
TIGHTEN
Fig. 6
05206
05207
FILL BEARING HOUSING
CA
VITY WITH SAE 10
NON-DETERGENT OIL
AFTER EVER Y 100
HOURS OF OPERATION
FRONT
COVER
Fig. 7