Graco 3325 HA-DD Use and care manual

3A6588B
EN
Operation, Repair, Parts
Pressure Washers
For high pressure water cleaning. For professional use only.
See page 3 for model information and maximum working pressure.
Important Safety Instructions
Read all warnings and instructions in this manual and in
gas engine manual before using the equipment. Save
these instructions.
Direct-Drive Models Belt-Drive Models

23A6588B
Contents
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Safety Symbol Table . . . . . . . . . . . . . . . . . . . . . . . . 4
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Component Identification . . . . . . . . . . . . . . . . . . . . 8
Direct-Drive Models . . . . . . . . . . . . . . . . . . . . . . 8
Component Identification . . . . . . . . . . . . . . . . . . . . 9
Belt-Drive Models . . . . . . . . . . . . . . . . . . . . . . . . 9
Pressure Relief Procedure . . . . . . . . . . . . . . . . . . 10
Before Starting the Machine . . . . . . . . . . . . . . . . . 11
Personal Protective Equipment . . . . . . . . . . . . . 11
Equipment Placement . . . . . . . . . . . . . . . . . . . . 11
Water Pump Oil . . . . . . . . . . . . . . . . . . . . . . . . . 11
Engine Fuel Tank . . . . . . . . . . . . . . . . . . . . . . . 11
Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Connect Water Supply . . . . . . . . . . . . . . . . . . . 12
Connect the hoses . . . . . . . . . . . . . . . . . . . . . . 12
Priming the Pump . . . . . . . . . . . . . . . . . . . . . . . 12
Nozzle Selection . . . . . . . . . . . . . . . . . . . . . . . . 13
Nozzle Connection . . . . . . . . . . . . . . . . . . . . . . 13
Starting the Washer . . . . . . . . . . . . . . . . . . . . . 14
Unloader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Cleaning with Detergents . . . . . . . . . . . . . . . . . 15
Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Winterizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Nozzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Quick Couplers . . . . . . . . . . . . . . . . . . . . . . . . . 17
Belt Tension Adjustment . . . . . . . . . . . . . . . . . . 17
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Parts - Direct-Drive . . . . . . . . . . . . . . . . . . . . . . . . 20
Models 25N634, 25N635, 25N636, 25N637,
25N638, 25N639, 25N640, 25N641, 25N677,
25N678, 25N681, 25N682 . . . . . . . . . . . . . 20
Parts List - Direct-Drive . . . . . . . . . . . . . . . . . . . . . 21
Models 25N634, 25N635, 25N636, 25N637,
25N638, 25N639, 25N640, 25N641, 25N677,
25N678, 25N681, 25N682 . . . . . . . . . . . . . 21
Parts List - Pump 17Z102, 17Z103, 17Z104 . . . . . 22
Models 25N634, 25N635, 25N636, 25N637,
25N638, 25N639, 25N640, 25N641 . . . . . . 22
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Parts - Pump 127385 . . . . . . . . . . . . . . . . . . . . . . . 23
Models 25N677, 25N681 . . . . . . . . . . . . . . . . . . 23
Parts - Pump 127383 . . . . . . . . . . . . . . . . . . . . . . . 24
Models 25N678, 25N682 . . . . . . . . . . . . . . . . . . 24
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Parts - Belt-Drive . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Models 25N679, 25N683, 25N680, 25N684 . . . 25
Parts List - Belt-Drive . . . . . . . . . . . . . . . . . . . . . . 26
Models 25N679, 25N683, 25N680, 25N684 . . . 26
Parts - Pump 127384 . . . . . . . . . . . . . . . . . . . . . . . 27
Models 25N679, 25N683 . . . . . . . . . . . . . . . . . . 27
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Parts - Pump 127382 . . . . . . . . . . . . . . . . . . . . . . . 28
Models 25N680, 25N684 . . . . . . . . . . . . . . . . . . 28
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Technical Specifications . . . . . . . . . . . . . . . . . . . . 29
CALIFORNIA PROPOSITION 65 . . . . . . . . . . . 32
Graco Standard Warranty . . . . . . . . . . . . . . . . . . . 33
Graco Information . . . . . . . . . . . . . . . . . . . . . . . . . 33

Models
3A6588B 3
Models
Part No. Model Operating Pressure Flow Engine Pump Drive
System
PSI MPa Bar GPM
25N634 3325 HA-DD 3300 22.7 227 2.5 Honda AR Direct Drive
25N638
25N635 3230 HA-DD 3200 22.1 221 3.0 Honda AR Direct Drive
25N639
25N636 4240 KA-DD 4200 29 290 4.0 Kohler AR Direct Drive
25N640
25N637 4240 HA-DD 4200 29 290 4.0 Honda AR Direct Drive
25N641
25N677 4040 HG-DD 4000 27.6 276 4.0 Honda GP Direct Drive
25N681
25N678 4040 HC-DD 4000 27.6 276 4.0 Honda CAT Direct Drive
25N682
25N679 4040 HG-BD 4000 27.6 276 4.0 Honda GP Belt Drive
25N683
25N680 4040 HC-BD 4000 27.6 276 4.0 Honda CAT Belt Drive
25N684

Safety Symbol Table
43A6588B
Safety Symbol Table
The following safety symbols appear throughout this manual and on warning labels. Read the table below to
understand what each symbol means.
Symbol Meaning
Burn Hazard
Moving Parts Pinch
Electric Shock Hazard
Fall Hazard
Fire and Explosion Hazard
Entanglement Hazard
Recoil Hazard
Skin Injection Hazard
Splash Hazard
Fire Hazard
Do Not Overfill Gas Tank
Toxic Fluid or Carbon Monoxide Hazard
Do Not Stop Leaks or Deflect Leaks
Do Not Spray People or Animals
Eliminate Ignition Sources
Hold Firmly With Both Hands
Perform Pressure Relief Procedure
Read Manual Before Using Equipment
Wear Personal Protective Equipment
Equipment Misuse Hazard
Symbol Meaning

Warnings
3A6588B 5
Warnings
The following warnings are for the setup, use, maintenance, and repair of this equipment. The exclamation point
symbol alerts you to a general warning and the hazard symbols refer to procedure-specific risks. When these
symbols appear in the body of this manual or on warning labels, refer back to these Warnings. Product-specific
hazard symbols and warnings not covered in this section may appear throughout the body of this manual where
applicable.
WARNING
CARBON MONOXIDE HAZARD
Exhaust contains poisonous carbon monoxide, which is colorless and odorless. Breathing carbon
monoxide can cause death.
• Do not operate internal combustion engine in an enclosed area.
• Ensure that any exhaust emissions are not in the vicinity of any air intakes.
RECOIL HAZARD
Gun may recoil when triggered. If you are not standing securely, you could fall and be seriously
injured.
• Hold onto gun/wand firmly with both hands to avoid kickbacks.
FALL HAZARD
Use of this equipment can create puddles and slippery surfaces. High pressure spray could cause you
to fall if you are too close to the cleaning surface.
• Keep apray nozzle between 8 to 24 inches (20 to 60 cm) away from cleaning surface.
• Always operate equipment on a stable surface.
• Cleaning area should have adequate slopes and drainage to reduce possibility of falls due to
slippery surfaces.
• Be extremely careful if you must operate equipment from ladder, scaffolding, or any other relatively
unstable location.
FIRE AND EXPLOSION HAZARD
Flammable vapors in the work area and can ignite or explode. To help prevent fire and explosion:
• Do not spray flammable liquids.
• Operate pressure washers outdoors only.
• Eliminate all ignition sources; such as pilot lights, cigarettes, portable electric lamps, and plastic
drop cloths (potential static arc).
• When transporting or repairing equipment, transport or repair with the fuel tank empty or with fuel
shutoff valve turned off.
• Do not fill fuel tank while engine is running or hot; shut off engine and let it cool. Leave 5/8 inch (16
mm) at top of tank for fuel expansion. Fuel is flammable and can ignite or explode if spilled on hot
surface.
• Keep work area free of debris, including solvent, rags and gasoline.

Warnings
63A6588B
ELECTRIC SHOCK HAZARD
Spray contact with electrical wiring can result in serious injury or death.
• Keep water spray away from electric wiring.
SKIN INJECTION HAZARD
High-pressure spray is able to inject toxins into the body and cause serious bodily injury. In the event
that injection occurs, get immediate surgical treatment.
• Keep clear of nozzle. Do not spray any person, yourself or any animal.
• Keep hands and other body parts away from the discharge. Do not try to stop leaks with any part
of the body.
• This product is to be used only by trained operators.
• Use caution when cleaning and changing nozzle tips. In the case where the nozzle tip clogs while
spraying, follow the Pressure Relief Procedure for turning off the unit and relieving the pressure
before removing the nozzle tip to clean.
• Do not leave the unit energized or under pressure while unattended. When the unit is not in use, turn
off the unit and follow the Pressure Relief Procedure for turning off the unit.
• Check hoses and parts for signs of damage. Replace any damaged hoses or parts.
• Use Graco replacement parts or accessories that are approved for the rated pressure of the
pressure washer.
• Always engage the trigger lock when not spraying. Verify the trigger lock is functioning properly.
• Verify that all connections are secure before operating the unit.
• Know how to stop the unit and bleed pressure quickly. Be thoroughly familiar with the controls.
BURN HAZARD
Running engines produce heat and hot exhaust gases. Temperature of muffler and nearby areas can
reach or exceed 150° F (65° C). Fire or severe burns can occur.
• Do not touch hot surfaces.
• Stay clear of exhaust gases.
• Never move equipment while operating.
• Allow equipment to cool before touching.
ENTANGLEMENT HAZARD
Rotating parts can cause serious injury.
• Keep clear of moving parts.
• Do not operate equipment with protective guards or covers removed.
TOXIC FLUID OR FUMES HAZARD
Toxic fluids or fumes can cause serious injury or death if splashed in the eyes or on skin, inhaled, or
swallowed.
• Do not use pressure washer to dispense hazardous detergents or acid-type cleaners.
• Do not alter chemical injector feature that is listed in the manual.
• Read Safety Data Sheets (SDSs) to know the specific hazards of the fluids you are using.
• Route exhaust away from work area.
WARNING

Warnings
3A6588B 7
EQUIPMENT MISUSE HAZARD
Misuse can cause death or serious injury.
• Always wear appropriate gloves, eye protection, and a respirator or mask when spraying.
• Do not operate or spray near children. Keep children away from equipment at all times.
• Do not overreach or stand on an unstable support. Keep effective footing and balance at all times.
• Stay alert and watch what you are doing.
• Do not leave the unit energized or under pressure while unattended. When the unit is not in use, turn
off the unit and follow the Pressure Relief Procedure for turning off the unit.
• Do not operate the unit when fatigued or under the influence of drugs or alcohol.
• Keep operating area clear of all persons.
• Do not kink or over-bend the hose.
• Do not expose the hose to temperatures or to pressures in excess of those specified by
manufacturer.
• Do not use the hose as a strength member to pull or lift the equipment.
• Follow the maintenance instructions specified in the manual.
• Do not alter or modify equipment. Alterations or modifications may void agency approvals and
create safety hazards.
• Make sure all equipment is rated and approved for the environment in which you are using it.
PERSONAL PROTECTIVE EQUIPMENT
Wear appropriate protective equipment when in the work area to help prevent serious injury, including
eye injury, hearing loss, inhalation of toxic fumes, and burns. Protective equipment includes but is not
limited to:
• Protective eyewear, and hearing protection.
• Respirators, protective clothing, and gloves as recommended by the detergent manufacturer.
The following instructions are required by California state law, section 4442 of the California Public
Resource Code. Other states may have similar laws. Federal laws apply on federal land.
• A spark arrestor must be added to the muffler of this engine if it is to be used on any forest-covered,
brush-covered, or grass-covered unimproved land.
•See your engine or equipment dealer for spark arrestor muffler options.
WARNING

Component Identification
83A6588B
Component Identification
Direct-Drive Models
A Water Pump
BEngine
C ON/OFF Switch
D Unloader
E High-Pressure Washer Hose
FGun
G Nozzles
H Chemical Injector Hose
I Pump Oil Cap
J Thermal Relief Valve
K Choke
L Fuel Valve
M High-Pressure Outlet
N Low-Pressure Inlet
OGasCap
P Trigger Lock

Component Identification
3A6588B 9
Component Identification
Belt-Drive Models
A Water Pump
BEngine
C ON/OFF Switch
D Unloader
E High-Pressure Washer Hose
FGun
G Nozzles
H Chemical Injector Hose
I Pump Oil Cap
J Thermal Relief Valve
K Choke
L Fuel Valve
M High-Pressure Outlet
N Low-Pressure Inlet
OGasCap
P Trigger Lock

Pressure Relief Procedure
10 3A6588B
Pressure Relief Procedure
Follow the Pressure Relief Procedure whenever
you see this symbol.
1. Engage trigger lock.
2. Turn unit off.
3. Shut off water supply. Disconnect from water.
4. Disengage trigger lock.
5. Trigger gun to relieve pressure.
6. Engage trigger lock.
7. If you suspect the nozzle or hose is clogged or that
pressure has not been fully relieved:
a. VERY SLOWLY dosconnect the hose from the
washer to relieve pressure.
b. Disconnect hose, gun, and nozzle completely.
c. Clear the obstruction in the hose or nozzle.
Thermal Relief Valve
To ensure the water temperature does not exceed
acceptable levels, never allow the unit to operate
continuously in bypass mode (unit running with gun
trigger closed) for more than three minutes.
All units have a thermal relief valve to protect the pump.
It may begin to open and release water if the water
temperature in the pump has exceeded 140°F (60°C).
This will allow fresh, cool water to enter the system.
This equipment stays pressurized until pressure is
manually relieved. To help prevent serious injury from
pressurized fluid, such as skin injection, splashing
fluid and moving parts, follow the Pressure Relief
Procedure when you stop spraying and before
cleaning, checking, or servicing the equipment.

Before Starting the Machine
3A6588B 11
Before Starting the Machine
Personal Protective Equipment
Equipment Placement
This unit should only be placed on a level surface while
operating to ensure proper lubrication for the engine and
water pump.
Be certain to block wheels to prevent unit from moving
while operating.
Water Pump Oil
Using the oil dipstick, check the oil level to assure the oil
is at the appropriate level.
Some units have an oil sight glass on the water pump.
Make sure the oil is at the maximum level before each
use. If the level appears to be low, add Pump Oil and fill
only to the max level on the dipstick. Do not overfill.
Engine Fuel Tank
A minimum of 86 octane fuel is recommended for use
with this unit. Do not mix oil with gasoline.
Purchase fuel in quantities that may be used within 30
days. Use of clean, fresh lead-free gasoline is
recommended. Leaded gasoline may be used if
lead-free is unavailable.
Occasional carburetor and choke adjustments will be
necessary for the engine. Refer to the engine manual
supplied with this unit for proper adjustment procedures.
Review the engine manual accompanying this pressure
washer for correct engine start-up and maintenance
procedures.
INJECTION AND INHALATION HAZARD
Proper attire is essential to your safety. It is advised to
utilize whatever means necessary to protect eyes,
ears and skin. Additional safety attire (such as
respiratory mask) may be required when using
detergent cleaning agents with this unit.
EXPLOSIVE FUEL CAN CAUSE FIRES AND
SEVERE BURNS
Stop engine before filling fuel tank. Leave 5/8 inch
(16mm) at top of tank for fuel expansion.

Setup
12 3A6588B
Setup
Connect Water Supply
Select a water supply hose which is a quality grade of
garden hose measuring at least 3/4 in. (19.05 mm) in ID
and no longer than 50 feet (15.24 m).
Check the water inlet strainer to make sure it is clean
and free of any obstructions. Periodic cleaning of the
water strainer will help prevent pump problems.
Connect the hoses
1. Connect one end of water supply hose to water inlet
of unit.
2. Connect other end of hose to pressurized water
supply. When connecting water inlet to water
supply, local regulations of your water company
must be observed. In some areas, the unit must not
be connected directly to public drinking water
supply. This prevents feedback of the detergents
into the water supply. Direct connection is permitted
if a back flow preventer is installed.
3. Connect high pressure washer hose to water outlet
of unit.
4. Connect other end of pressure washer hose to gun
assembly.
Follow incoming water requirements listed below:
1. Water pressure must be a minimum of 25 psi (0.17
MPa,1.72 bar) and a maximum of 125 psi (0.86
MPa, 8.6 bar). NOTE: A typical outdoor faucet will
generally supply this psi if fully turned on.
2. Incoming GPM must be at least one gallon more
than the outgoing GPM stated on pressure washer
nameplate. NOTE: You can check GPM by timing
how long it takes to fill a 5 gallon container.
3. Incoming water temperature must not exceed 140°
F (60° C).
Priming the Pump
It is essential to prime the pump on initial start-up and
each time the water supply is disconnected from the unit
after initial use.
1. Lay high pressure hose out straight to eliminate the
possibility for kinks to restrict flow.
NOTE: The nozzle assembly should not be
connected to the gun assembly at this time.
2. Engage trigger lock and point gun away from
yourself or anyone else. Make sure water supply is
fully turned on.
3. Disengage trigger lock and squeeze trigger.
NOTE: Low pressure water will begin flowing from
hose/gun assembly. This allows unit to prime and
purge any air from system. Unit is primed when
water flow is uninterrupted by air.
4. Once unit is primed, release trigger and engage
trigger lock. Securely connect nozzle assembly. See
Nozzle Connection, page 13.
NOTICE
As a strainer becomes obstructed, it restricts proper
flow of water to the pump. This can result in cavitation
which will cause premature failure of pump packings.
NOTICE
Excessive pump damage may result if the water tem-
perature exceeds acceptable levels.
Never allow the unit to operate without the incoming
water line attached and the water supply fully turned
on. Damage to the equipment could occur.
NOTICE
Make sure the nozzle is not connected to the unit
while priming the pump. Priming allows mineral
deposits to be released from the system which could
obstruct or damage the nozzle assembly resulting in
costly repairs.

Setup
3A6588B 13
Nozzle Selection
Various nozzles may be quick-connected into the end of
the wand to change the spray pattern or use the
detergent feature.
0° - BLASTING
• Removing caked on mud from heavy construction,
farm or lawn equipment.
• Cleaning tar, glue or stubborn stains from concrete.
• Cleaning overhead areas.
• Removing rust from steel and oxidation from
aluminum.
15° - STRIPPING
• Removing paint from wood, masonry or metal.
• Removing grease or dirt from equipment.
• Removing heavy mildew stains.
• Removing marine growth from boats and marine
equipment.
• Removing rust from steel and oxidation from
aluminum.
25° - CLEANING
• General cleaning of dirt, mud and grime.
• Cleaning roofs, gutters and downspouts.
• Removing light mildew stains.
• Removing algae and bacteria build-up from pools.
• Rinsing surfaces in preparation for painting.
40° - WASHING
• Light cleaning and washing.
• Washing and rinsing of automobiles and boats.
• Cleaning roofs, windows, patios and driveways.
65° - CHEMICAL/DETERGENT
• Applying chemicals/detergents at low pressure to
help clean the surface.
• Tough stains that require the aid of a chemical
agent to remove.
Nozzle Connection
1. Perform Pressure Relief Procedure, page 10.
2. Engage trigger lock.
3. Connect nozzle by retracting the locking ring on the
quick-connect fitting and inserting the nozzle.
4. Verify the locking ring returns to its operating
position after inserting the nozzle.
EJECTED PARTS HAZARD
When using quick connects, be certain the connection
is securely locked. If connections are not securely
locked, the high pressure water may eject the nozzle
from the wand, causing severe injury or serious
damage. Always point wand away from you when
changing nozzle.

Setup
14 3A6588B
Starting the Washer
1. Engage trigger lock and point gun away from
yourself or anyone else. Make sure water supply is
fully turned on.
2. Verify pump is primed. See Priming the Pump,
page 12.
3. Turn the engine switch to the ON position, as well
as the fuel valve (if supplied with) and adjust choke
as needed. Then start engine by pulling recoil rope.
4. Disengage trigger lock and trigger gun several
times. Verify high pressure water is sprayed.
5. Make sure to engaged trigger lock whenever
changing nozzles and/or when not in use.
This pressure washer delivers a high pressure spray
and a variety of spray patterns. There are many
cleaning jobs that can be done without the use of
detergents. If a cleaning agent is required, see
Cleaning with Detergents, page 15, for correct
procedures.
Unloader
Adjustment Knob
The unloader valve on your machine is equipped with an
adjustment knob to adjust the pressure. If less pressure
is needed, turn the adjustment knob counter-clockwise.
To set back to maximum, turn adjustment knob fully
clockwise. Do not over tighten.
Never look directly into the nozzle. High pressure
water creates a risk for severe injury.
Brace yourself. Hold onto gun/wand firmly with both
hands. Gun will kick back from high pressure created
by pump once engine has started.
NOTICE
Do not allow unit to operate in bypass mode (with trig-
ger closed) for more than three minutes without trig-
gering gun. This can cause premature failure of pump
packing seals and result in costly pump repair.
NOTICE
Do not allow spray pattern to remain on a fixed area
for an extended period of time. Possible damage to
that area may occur.
NOTICE
Do not overtighten the unloader. Breakage could
result in immediate loss of water pressure and costly
repairs.

Setup
3A6588B 15
Cleaning with Detergents
All units are equipped with a chemical injection kit.
Locate the clear vinyl hose that is shipped with your unit.
NOTE: This injection system is designed to apply
detergents under low pressure only. It will not allow
detergent solutions to be introduced into the system
unless the chemical/detergent nozzle is used.
1. Perform Pressure Relief Procedure, page 10.
2. Install chemical injector hose between the pump
outlet and the high-pressure washer hose inlet. For
washers shipped with an integrated chemical
injector, attach the clear chemical injection tube to
the barb on the injector.
3. Adjust pressure to the lowest point by turning the
pressure knob counterclockwise on the unloader
valve.
4. Immerse detergent strainer into detergent solution
to allow detergent to siphon.
5. Engage trigger lock and secure the
chemical/detergent nozzle (65° BLACK) into end of
wand. See Nozzle Connection, page 13.
6. Start the washer. See Starting the Washer, page
14.
7. To apply solution; disengage trigger lock and
squeeze trigger. A detergent/water mixture will exit
low pressure nozzle. Start spraying lower portion of
surface being cleaned and move up, using long
overlapping strokes. NOTE: Applying from the
bottom up helps to avoid streaking. Allow to soak
briefly. Do not allow detergent solution to dry on the
surface. Avoid working on hot surfaces or in direct
sunlight to minimize the chances of the detergent
drying, which may result in damaging painted
surfaces. Rinse a small section at a time.
8. To rinse; engage trigger lock and securely connect
desired high pressure nozzle into end of wand.
Disengage trigger lock and spray. It will take about
30 seconds to purge all detergent from line. For best
rinsing results, start at the top and work down. See
Nozzle Connection, page 13.
9. Siphon a gallon of water through low pressure
detergent injection system after each use. This
reduces the possibility of corrosion or detergent
residue causing mechanical problems during next
use.
Shutdown
1. Perform Pressure Relief Procedure, page 10.
2. Once pressure is relieved, disconnect nozzle
assembly.
3. Disconnect and drain gun, wand and hose.
4. Wipe unit clean and store with gun, wand and hoses
in a non-freezing area. See Storage, page 16.
BURN OR EXPLOSION HAZARD
Always wear protective safety attire.
Prepare detergent solution according to label
directions. Never pump hazardous detergents or
acid-type cleaners through unit.

Storage
16 3A6588B
Storage
1. Shut off unit and water supply.
2. Relieve system pressure by pointing gun away from
yourself and anyone else and squeezing trigger until
water flow ceases to exit nozzle.
3. Disconnect and drain hose, gun and wand.
4. Start unit and allow it to run until all water exits from
unit. Once water has stopped flowing from unit, turn
unit off.
5. Store hose, gun and wand with unit in a
non-freezing area.
Winterizing
For storage and transportation purposes in subfreezing
ambient temperatures, it will be necessary to winterize
the unit. The unit must be protected to the lowest
incurred temperature to prevent permanent damage.
If you must store the unit in an area where the
temperature falls below 32° F (0° C), perform the
following steps:
Gather the following items:
• Two 5 gallon (18.9 liter) containers.
• One gallon (3.8 liter) of antifreeze.
• Water supply.
• Three foot (0.92 m) hose, 1/2-3/4 in. (13-19 mm) ID
with a 3/4 in. male garden hose fitting.
Procedure
1. To start winterizing, unit must be primed (see
Priming the Pump, page 12.).
2. After priming, perform Pressure Relief Procedure,
page 10.
3. Engage trigger lock and remove nozzle.
4. In one 5 gallon (18.9 liter) container, mix antifreeze
and water according to manufacturer’s
recommendations for winterizing temperature.
NOTE: Proper winterizing is based on the
recommended manufacturer’s instructions listed on
the Protections Chart shown on the back label of
most antifreeze containers.
5. Remove water supply hose from unit and attach 3 ft
hose securely to inlet connection. Submerge other
end into antifreeze solution.
6. Point wand into empty container and start unit.
7. Trigger gun until antifreeze begins to exit wand.
Release trigger for 3 seconds, then trigger gun for 3
seconds. Continue cycling gun several times until all
antifreeze mixture is siphoned from container.
8. Shut engine off.
9. Detach 3 ft hose from unit and drain any excess
antifreeze back into 5 gallon (18.9 liter) container.
10. Disconnect hose/gun/wand assembly from unit and
drain any excess antifreeze back into 5 gallon (18.9
liter) container.
11. Store antifreeze solution for next use or dispose of
according to local regulations.
NOTICE
If unit was stored in this manner, but exposed to
freezing temperatures, caution should be used as ice
chips can form from drops of water which could lead
to equipment damage. Allow unit to completely thaw
before starting.
NOTICE
The pumping system in this unit may be permanently
damaged if any part of the system becomes frozen.
Freeze damage is not covered by warranty.
NOTICE
Do not operate unit in a freezing environment. Dam-
age to washer could occur.

Maintenance
3A6588B 17
Maintenance
Engine
The engine instructions that accompany the unit detail
specific procedures for engine maintenance. Following
the engine manufacturer's recommendations will extend
engine life.
Pump
The pump oil must be changed after the first 25 hours of
operation on all units. Once the initial oil change has
been completed, it is recommended the oil be changed
every 3 months or 250 hour intervals. If oil appears dirty
or milky, changes may be required at a greater
frequency. Add pump oil and fill only to the center of the
sight glass or max level on dipstick. Refer to the parts
listing for the correct pump oil. Do not overfill.
Nozzles
Water flow through the spray nozzle will erode the
orifice, making it larger and result in a pressure loss.
Nozzles should be replaced whenever pressure is less
than 85% of the maximum. The frequency of
replacement will depend upon such variables as mineral
content in the water and number of hours the nozzle is
used.
Quick Couplers
There is an o-ring seal inside the female quick couplers.
This o-ring will deteriorate or, if the unit is allowed to
pump without the high pressure hose or nozzle
attached, the o-ring may be blown out occasionally.
Insert a replacement o-ring to correct the leak.
Additional o-rings can be purchased from your dealer.
Belt Tension Adjustment
To maintain peak performance, it may be necessary to
occasionally adjust the belt tension. Perform the
following steps:
1. Remove belt guard and loosen two nuts on each
side of pump.
2. Turn cap screw clockwise until a 1/2 in. (12.7 mm)
belt deflection is noticed between the pulleys.
3. Tighten side nuts.
4. Put a straight edge across both pulleys. If
necessary, loosen one set of pulley screws and
adjust in or out to properly align. Tighten pulley
screws and check tension again.
5. Replace belt guard and tighten fasteners securely.

Troubleshooting
18 3A6588B
Troubleshooting
1. Follow Pressure Relief Procedure, page 10,
before checking or repairing gun.
2. Check all possible problems and causes before
disassembling gun.
Problem Cause Solution
Engine not starting or hard to start No gasoline in fuel tank or carburetor Fill the tank with gasoline and open
fuel shut off valve.
Check fuel line to carburetor.
Low oil Add oil to proper level.
Start/Stop switch in STOP position Move switch to START position.
Water in fuel, or old fuel Drain fuel tank and carburetor. Use
new fuel, and make sure spark plug is
dry.
Engine flooded or improperly choked Open choke, and crank engine
several times to clear out gas. Make
sure spark plug is dry.
Dirty air cleaner filter Remove and clean.
Dirty spark plug, wrong gap, or wrong
type
Clean spark plug, adjust the gap, or
replace.
Gun not triggered Trigger gun while starting engine.
Engine not operating properly or
lacking power
Partially plugged air cleaner filter Remove and clean.
Spark plug dirty, wrong gap, or wrong
type
Clean spark plug, adjust the gap, or
replace.
Pressure too low and/or pump
running roughly
Worn or wrong size nozzle Replace with nozzle of proper size
Inlet filter clogged Clean filter. Check more frequently.
Worn packings, abrasives in water, or
natural wear
Check filter. Replace packings.
Inadequate water supply Check water flow rate to pump.
Belts slipping Tighten or replace belts; use correct
belts, and replace both at same time.
Fouled or dirty inlet or discharge
valves
Clean inlet and discharge valve
assemblies. Check filter.
Restricted inlet Check if garden hose is collapsed or
kinked.
Worn inlet or discharge valves Replace worn valves.
Leak in high-pressure hose Replace high-pressure hose.
Water leaking from under pump
manifold
Worn packings Install new packings.

Troubleshooting
3A6588B 19
Water in pump oil Humid air condensing inside
crankcase
Change oil as specified in
Maintenance on page 17.
Worn packings Install new packings.
Oil seals are leaking Install new oil seals.
Packings failing frequently or
prematurely
Scored, damaged, or worn plungers Install new plungers.
Abrasive material in the fluid being
pumped
Install proper filtration on pump inlet
plumbing.
Inlet water temperature too high Check water temperature. It should
not exceed 140°F (60°C).
Over pressurized pump Do not modify any factory-set
adjustments. See Equipment
Misuse Hazard on page 7.
Excessive pressure due to partially
plugged or damaged nozzle
Clean or replace nozzle. See Nozzle
Connection on page 13.
Pump running too long without
spraying
Never run pump more than 3 minutes
without spraying.
Running pump dry Do not run pump without water.
Strong surging at inlet, and low
pressure on discharge side
Foreign particles in the inlet or
discharge valve, or worn inlet and/or
discharge valves
Clean or replace valves.
No detergent is being siphoned into
system
Incorrect nozzle installed Install chemical/detergent nozzle
Pressure too high Adjust pressure to lowest point
Worn chemical injector valve Install new chemical injector valve
Problem Cause Solution

Parts - Direct-Drive
20 3A6588B
Parts - Direct-Drive
Models 25N634, 25N635, 25N636, 25N637, 25N638, 25N639, 25N640,
25N641, 25N677, 25N678, 25N681, 25N682