DeWalt 3400 Gas Pressure Washer Instruction Manual

June 13, 2024
Dewalt

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DeWalt 3400 Gas Pressure Washer

DeWalt-3400-Gas-Pressure-Washer-product

Product Information

The product is a pressure washer with an engine. It is designed to be used for various cleaning tasks. The pressure washer comes with a handle assembly, a pump, a high-pressure hose, a spray gun, and quick connect nozzles. The engine requires oil and gasoline for operation.

Warnings and Important Information

  • Read the pressure washer instruction manual and the engine instruction manual before operating the pressure washer to reduce the risk of injury.
  • Do not allow the unit to run for more than two minutes without pulling the gun trigger to prevent overheating and pump damage.
  • Make sure to connect the water supply and turn it on before running the unit. Use cold water only.
  • Read and follow the instructions on the container of Ethanol ShieldTM fuel stabilizer if using it with the gasoline.
  • This guide is not a substitute for reading the operator’s manual. Users must read and understand the operator’s manual before using this product.

Product Usage Instructions

  1. Handle Assembly: Slide the handle assembly onto the frame, align holes, insert saddle bolts, and secure in place with knobs. Tighten until snug. Align holes in the top handle with the mounting holes in the handle assembly. Insert saddle bolts through aligned holes and secure the top handle to the handle assembly with knobs. Tighten until snug.
  2. Add/Check Oil: Before starting the engine, add the provided oil. Check the oil level prior to each use. Refer to the Engine Owner’s Manual for the complete procedure.
  3. Add Gasoline: In a well-ventilated outdoor area, add fresh, high-quality, unleaded gasoline with a pump octane rating of 86 or higher. Do not overfill. Wipe up spilled fuel before starting the engine. Refer to the Engine Owner’s Manual for the complete procedure. Optionally, use an Ethanol ShieldTM fuel stabilizer by following the instructions on the container and adding it to the gasoline.
  4. Connect Garden Hose to Pump: Thread the garden hose to the pump inlet.
  5. Connect High-Pressure Hose to Pump: Connect the high-pressure hose to the pump outlet.
  6. Connect High-Pressure Hose to Spray Gun: Connect the other end of the high-pressure hose to the spray gun.
  7. Connect Spray Wand to Spray Gun: Thread the spray wand into the end of the spray gun.
  8. Connect QC Nozzles to Spray Wand: Pull the Quickly connect the coupler back and insert the nozzle. Release the quick-connect coupler and twist the nozzle to ensure it is secure in the coupler.
  9. Turn the Water Faucet Completely On Do not run the unit without the water supply connected and turned on. Use cold water only.
  10. Release Air from the System: Release all air from the pump and high-pressure hose by depressing the trigger until a steady stream of water is present. Approximately 30 seconds.
  11. Verify Engine Switch Position: Make sure the engine switch is turned to the “On” position.
  12. Move Choke Position: Move the choke to the “Closed” position.
  13. Pull Recoil Starter Grip: Pull the recoil starter grip to start the engine.
  14. Place Fuel Valve Lever: Place the fuel valve lever in the “On” position.
  15. Move Choke Position: Move the choke to the “Open” position.

QUICK SETUP GUIDE

WARNING:
To reduce the risk of injury, read the pressure washer instruction manual and the engine instruction manual before operating the pressure washer.

Install the Handle

  • Slide the handle assembly onto the frame, align holes, insert saddle bolts, and secure in place with knobs. Tighten until snug.

  • Align holes in the top handle with the mounting holes in the handle assembly.

  • Insert saddle bolts through aligned holes and secure the top handle to handle assembly with knobs. Tighten until snug.

  • Add/Check Oil
    The engine is shipped without oil. Before starting the engine, add the oil provided. Check the oil level prior to each use. Refer to Engine Owner’s Manual for complete procedure.

  • Add Gasoline
    In a well-ventilated outdoor area add fresh, high-quality, unleaded gasoline with a pump octane rating of 86 or higher. Do not overfill. Wipe up spilled fuel before starting the engine. Refer to the Engine Owners Manual for the complete procedure.

IMPORTANT:
Ethanol Shield™ (sold separately) is a fuel stabilizer that helps eliminate and prevent ethanol-related problems in power equipment. Follow the instructions on the container and add to the gasoline.

QUICK START GUIDE

DANGER:

  • Never run the engine indoors or in enclosed, poorly ventilated areas. Engine exhaust contains carbon monoxide, an odorless and deadly gas.
  • Risk of fluid injection and laceration. When using the high-pressure setting, DO NOT allow the high-pressure spray to come in contact with unprotected skin, eyes or with any pets or animals. Serious injury will occur.

WARNING:
Do not allow the unit to run for more than two minutes without the gun trigger being pulled. This could cause overheating and damage to the pump. When the temperature inside the pump rises too high, the thermal relief valve will open and release a spray of water from the pump to lower the internal temperature. The valve will then close.

  1. Connect Garden Hose to Pump
    Thread the garden hose to the pump inlet.DeWalt-3400-Gas-Pressure-Washer-
fig- \(4\)

  2. Connect High-Pressure Hose to Pump
    Connect the high-pressure hose to the pump outlet.

  3. Connect High-Pressure Hose to Spray Gun
    Connect the other end of the high-pressure hose to the spray gun.

  4. Connect Spray Wand to Spray Gun
    Thread the spray wand into the end of the spray gun.

  5. Connect QC Nozzles to Spray Wand
    Pull quick quick-connect coupler back and insert a nozzle. Release the quick- connect coupler and twist the nozzle to make sure it is secure in the coupler.

  6. Turn Water Faucet Completely On
    Do not run the unit without the water supply connected and turned on. Use Cold Water Only.

  7. Release Air from the System
    Release all air from the pump and high-pressure hose by depressing the trigger until a steady stream of water is present. Approximately 30 seconds.

  8. Verify the Engine Switch is turned to the ON Position

  9. Place the fuel valve lever in the ON position.

  10. Move the choke to the CLOSED position

  11. Pull the Recoil Starter Grip
    Pull the recoil starter grip to start the engine.

  12. Move the choke to the OPEN position

WARNING:
This Guide is not a substitute for reading the operator’s manual. Users must read and understand the operator’s manual before using this product.

Engine
Refer to the engine instruction manual for the location and operation of other engine controls.

Pump
The Pump was filled with oil at the factory. The preferred oil is SIMPSON® Premium Pump Crankcase Oil. If this oil is not available, an SAE 15W-40 oil may be used. Change the pump oil after the first 50 hours of operation and every 100 hours thereafter, or every 3 months.

Definitions: Safety Alert Symbols and Words
This instruction manual uses the following safety alert symbols and words to alert you to hazardous situations and your risk of personal injury or property damage. DANGER: Indicates an imminently hazardous situation that, if not avoided, will result in death or serious injury.

  • WARNING: Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
  • CAUTION: Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. (Used without a word) Indicates a safety-related message.
  • NOTICE: Indicates a practice not related to personal injury which, if not avoided, may result in property damage.
  1. Panel assembly
  2. Nozzle holder
  3. Professional spray gun
  4. Wheel
  5. Quick-connect spray wand
  6. Frame
  7. Engine dipstick/oil plug
  8. Engine switch
  9. Starter grip
  10. Engine
  11. Throttle control lever
  12. Choke control
  13. Fuel valve lever
  14. Gas cap
  15. Handle assembly
  16. High-pressure hose
  17. High-pressure pump
  18. Top handle

DeWalt-3400-Gas-Pressure-Washer-fig- \(17\)

  • WARNING: Read all safety warnings and all instructions. Failure to follow the warnings and instructions may result in electric shock, fire and/or serious injury.
  • WARNING: To reduce the risk of injury, read the instruction manual.

IF YOU HAVE ANY QUESTIONS OR COMMENTS ABOUT THIS CONTACT US AT: 1–877–362–4271

Important Safety Instructions

  • DANGER: Carbon Monoxide. Using an engine indoors can kill you in minutes. Engine exhaust contains high levels of carbon monoxide (CO), a poisonous gas you cannot see or smell. You may be breathing CO even if you do not smell engine exhaust.

  • WARNING: This product and its exhaust contain chemicals known to the State of California to cause cancer, birth defects, and other reproductive harm.

    • NEVER use an engine inside homes, garages, crawlspaces, or other partly enclosed areas. Deadly levels of carbon monoxide can build up in these areas. Using a fan or opening windows and doors does NOT supply enough fresh air.

    • ONLY use outdoors and far away from open windows, doors, and vents. These openings can pull in engine exhaust.

    • Even when the engine is used correctly, CO may leak into your home. ALWAYS use a battery-powered or battery-backup CO alarm
      in your house. Read and follow all directions for the CO alarm before using it. If you feel sick, dizzy, or weak at any time, move to fresh air immediately. See a doctor. You could have carbon monoxide poisoning.

    • WARNING: Do not operate this unit until you read this instruction manual and the engine instruction manual for safety, operation, and maintenance instructions.

WARNING: When using this product basic precautions should always be followed, including the following:

  1. Read all instructions before using the product. 2 . To reduce the risk of injury, close supervision is necessary when a product is used near children.
  2. Know how to stop the product and bleed pressures quickly. Be thoroughly familiar with the controls.
  3. stay alert–watch what you are doing.
  4. Do not operate the product when fatigued or under the influence of alcohol or drugs.
  5. Keep the operating area clear of all persons.
  6. Do not overreach or stand on unstable support. Keep good footing and balance at all times.
  7. Follow the maintenance instructions specified in the manual.

DANGER:
RISK OF INJECTION OR SEVERE INJURY. KEEP CLEAR OF NOZZLE. DO NOT DIRECT DISCHARGE STREAM AT PERSONS. THIS PRODUCT IS TO BE USED ONLY BY TRAINED OPERATORS.

WARNING:
This product may not be equipped with a spark-arresting muffler. If the product is not equipped and will be used around flammable materials or on land covered with materials such as agricultural crops, forest, brush, grass or other similar items, then an approved spark arrester must be installed and is legally required in the state of California. It is a violation of California statutes section 130050 and/or sections 4442 and 4443 of the California Public Resources Code, unless the engine is equipped with a spark arrester, as defined in section 4442, and maintained in effective working order. Spark arresters are also required on some U.S. Forest Service land and may also be legally required under other statutes and ordinances.

WARNING:
This product and its exhaust can expose you to chemicals including lead and lead compounds, and carbon monoxide, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

SAVE THESE INSTRUCTIONS

DANGER: RISK OF EXPLOSION OR FIRE

WHAT CAN HAPPEN

  • Spilled gasoline and it’s vapors can become ignited from cigarette sparks, electrical arcing, exhaust gases and hot engine components such as the muffler.
  • Heat will expand fuel in the tank which could result in spillage and possible fire explosion.
  • Operating the pressure washer in an explosive environment could result in a fire.
  • Materials placed against or near the pressure washer can interfere with its proper ventilation features causing overheating and possible ignition of the materials.
  • Muffler exhaust heat can damage painted surfaces, melt any material sensitive to heat (such as siding, plastic, rubber, vinyl or the pressure hose, itself), and damage live plants.
  • Improperly stored fuel could lead to accidental ignition. Fuel improperly secured could get into the hands of children or other unqualified persons.
  • Use of acids, toxic or corrosive chemicals, poisons, insecticides, or any kind of flammable solvent with this product could result in serious injury or death.

HOW TO PREVENT IT

  • Shut off the engine and allow it to cool before adding fuel to the tank.
  • Use care in filling the tank to avoid spilling fuel. Move the pressure washer away from the fueling area before starting the engine.
  • Keep the maximum fuel level 1/2″ (12.7 mm) below the bottom of the filler neck to allow for expansion.
  • Operate and fuel equipment in well-ventilated areas free from obstructions. Equip areas with fire extinguishers suitable for gasoline fires.
  • Never operate a pressure washer in an area containing dry brush or weeds.
  • Always keep the pressure washer a minimum of 4′ (1.2 m) away from surfaces (such as houses, automobiles or live plants) that could be damaged from muffler exhaust heat.
  • Store fuel in an OSHA-approved container, in a secure location away from the work area.
  • Do not spray flammable liquids.

DANGER: RISK TO BREATHING (ASPHYXIATION

WHAT CAN HAPPEN

  • Breathing exhaust fumes will cause serious injury or death! Engine exhaust contains carbon monoxide, an odorless and deadly gas.
  • Some cleaning fluids contain substances that could cause injury to the skin, eyes, or lungs.

HOW TO PREVENT IT

  • Operate pressure washers in a well-ventilated area. Avoid enclosed areas such as garages, basements, etc.
  • Never operate a unit in or near a location occupied by humans or animals.
  • Use only cleaning fluids specifically recommended for high-pressure washers. Follow the manufacturer’s recommendations. Do not use chlorine bleach or any other corrosive compound.

DANGER: RISK OF FLUID INJECTION AND LACERATION

WHAT CAN HAPPEN

  • Your pressure washer operates at fluid pressures and velocities high enough to penetrate human and animal flesh which could result in amputation or other serious injury. Leaks caused by loose fittings or worn or damaged hoses can result in injection injuries. DO NOT TREAT FLUID INJECTION AS A SIMPLE CUT! See a physician immediately!
  • Your pressure washer operates at fluid pressures and velocities high enough to penetrate human and animal flesh which could result in amputation or other serious injury. Leaks caused by loose fittings or worn or damaged hoses can result in injection injuries. DO NOT TREAT FLUID INJECTION AS A SIMPLE CUT! See a physician immediately!
  • Injuries can result if system pressure is not reduced before attempting maintenance or disassembly.

HOW TO PREVENT IT

  • Inspect the high-pressure hose regularly. Replace the hose immediately if it is damaged, worn, has melted from contacting the engine, or shows any signs of cracks, bubbles, pinholes, or other leakage. Never grasp a high-pressure hose that is leaking or damaged.
  • Never touch, grasp, or attempt to cover a pinhole or similar water leak on the high-pressure hose. The stream of water IS under high pressure and WILL penetrate the skin.
  • Never place hands in front of the nozzle.
  • Direct spray away from self and others.
  • Make sure the hose and fittings are tightened and in good condition. Never hold onto the hose or fittings during operation.
  • Do not allow the hose to contact the muffler.
  • Never attach or remove wand or hose fittings while the system is pressurized.
  • When using replacement lances or guns with this pressure washer, do not use a lance and/or lance/gun combination that is shorter in length than what was provided with this pressure washer as measured from the nozzle end of the lance to the gun trigger.
  • To relieve the system pressure, shut off the engine, turn off the water supply, and pull the gun trigger until the water stops flowing.
  • Use only accessories rated equal to or higher than the rating of the pressure washer.

DANGER: RISK OF INJURY FROM SPRAY

WHAT CAN HAPPEN

  • High-velocity fluid spray can cause objects to break, projecting particles at high speed.
  • Light or unsecured objects can become hazardous projectiles.
  • If proper starting procedure is not followed, the engine can kick back causing serious hand and arm injuries.
  • The spray gun/wand is a powerful cleaning tool that could look like a toy to a child.
  • The reactive force of the spray will cause the gun/wand to kick back and could cause the operator to slip or fall or misdirect the spray. Improper control of a gun/wand can result in injuries to self and others.

HOW TO PREVENT IT

  • Always wear ANSI-approved Z87.1 safety glasses. Wear protective clothing to protect against accidental spraying.
  • Never point the wand at or spray people or animals.
  • Always secure the trigger lock when the wand is not in service to prevent accidental operation.
  • Never permanently secure the trigger in the pull-back (open) position.
  • If the engine does not start after two pulls, squeeze the trigger of the gun to relieve pump pressure. Pull the starter cord slowly until resistance is felt. Then pull the cord rapidly to avoid kickback and prevent hand or arm injury.
  • Keep children away from the pressure washer at all times.
  • Do not overreach or stand on an unstable support.
  • Do not use a pressure washer while standing on a ladder.
  • Grip the gun/wand firmly with both hands. Expect the gun to kick back when triggered.

DANGER: RISK OF INJURY OR PROPERTY DAMAGE WHEN TRANSPORTING OR STORING

WHAT CAN HAPPEN

  • Fuel or oil can leak or spill and could result in fire or breathing hazards. Serious injury or death can result. Fuel or oil leaks will damage carpet, paint or other surfaces in vehicles or trailers.
  • Oil could fill the cylinder and damage the engine if the unit is not stored or transported in an upright position.

HOW TO PREVENT IT

  • If a pressure washer is equipped with a fuel shut-off valve, turn the valve to the off position before transporting to avoid fuel leaks. If a pressure washer is not equipped with a fuel shut-off valve, drain the fuel from the tank before transporting.
    Only transport fuel in an OSHA-approved container. Always place a pressure washer on a protective mat when transporting to protect against damage to the vehicle from leaks. Always transport and store the unit in an upright position. Remove the pressure washer from the vehicle immediately upon arrival at your destination.

DANGER: RISK OF ELECTRICAL SHOCK

WHAT CAN HAPPEN
Spray directed at electrical outlets or switches, or objects connected to an electrical circuit, could result in a fatal electrical shock.

HOW TO PREVENT IT
Unplug any electrically operated product before attempting to clean it. Direct spray away from electric outlets and switches.

DANGER: RISK OF CHEMICAL BURN

WHAT CAN HAPPEN
Use of acids, toxic or corrosive chemicals, poisons, insecticides, or any kind of flammable solvent with this product could result in serious injury or death.

HOW TO PREVENT IT

  • Do not spray acids, gasoline, kerosene, or any other flammable materials with this product. Use only household detergents, cleaners, and degreasers recommended for use with pressure washers.
  • Wear protective clothing to protect eyes and skin from contact with sprayed materials.

WARNING: RISK OF BURSTING

WHAT CAN HAPPEN

  • Overinflation of tires could result in serious injury and property damage.
  • High-velocity fluid spray directed at pneumatic tire sidewalls (such as found on automobiles, trailers, and the like) could damage the sidewall resulting in serious injury.

HOW TO PREVENT IT

  • Use a tire pressure gauge to check the tire pressure before each use and while inflating tires; see the tire sidewall for the correct tire pressure.
  • On pressure washers rated above 1600 psi (11032 kPa) use the widest fan spray (40º nozzle) and keep the spray a minimum of 8″ (200 mm) from the pneumatic tire sidewall. Do not aim spray directly at the joint between the tire and rim.

NOTE:
Air tanks, compressors, and similar equipment used to inflate tires can fill small tires similar to very rapidly. Adjust the pressure regulator on the air supply to no more than the rating of the tire pressure. Add air in small increments and frequently use the tire gauge to prevent overinflation.

WARNING: RISK OF HOT SURFACES

WHAT CAN HAPPEN
Contact with hot surfaces, such as engine exhaust components, could result in serious burns.

HOW TO PREVENT IT
During operation, touch only the control surfaces of the pressure washer. Keep children away from the pressure washer at all times. They may not be able to recognize the hazards of this product.

WARNING: RISK OF INJURY FROM LIFTING

WHAT CAN HAPPEN
Serious injury can result from attempting to lift too heavy an object.

HOW TO PREVENT IT
The pressure washer is too heavy to be lifted by one person. Obtain assistance from others before lifting.

SAVE THESE INSTRUCTIONS FOR FUTURE USE

INSTALLATION

Pressure Washer Assembly (Fig. A–F)

  1. Slide the handle assembly 15 onto the frame 6. Align holes, insert saddle bolts 30, and secure in place with knobs 31. Tighten until snug. CAUTION: Risk of personal injury. Avoid placing hands between the handle and frame when assembling to prevent pinching.
  2. Align holes in the top handle 18 with the mounting holes in the handle assembly 15.
  3. Insert saddle bolts 30 through aligned holes and secure the top handle to handle assembly with knobs 31. Tighten until snug.
  4. Attach high-pressure hose 16 to the spray gun. Make sure it is secure.
  5. Connect wand 5 to the spray gun. Make sure the connection is secure.
  6. Place the nozzle holder 2 onto panel assembly 1 and push each nozzle holder into place.
  7. Remove the five colored quick-connect nozzles from the plastic bag and insert them into the correct grommet on the nozzle holder. Nozzles are color-coded to match colored nozzles on panel assembly.

NOTE:
The high-pressure pump was filled with oil at the factory. Always check the oil level before using (refer to Maintenance for more information).

WARNING:
Risk of bursting. Use a tire pressure gauge to check the tire pressure before each use and while inflating tires; see the tire sidewall for the correct tire pressure.

NOTE:
Air tanks, compressors, and similar equipment used to inflate tires can fill small tires similar to very rapidly. Adjust the pressure regulator on the air supply to no more than the rating of the tire pressure. Add air in small increments and frequently use the tire gauge to prevent overinflation.

OPERATION

Pressure Adjustments
The pressure setting is preset at the factory to achieve optimum pressure and cleaning. To lower the pressure, follow these instructions.

  1. Back away from the surface to be cleaned. The further away you are, the less the pressure will be on the surface to be cleaned.
  2. Change to the 40˚ nozzle (white). This nozzle delivers a less powerful stream of water and a wider spray pattern. Refer to Spray Wand Nozzles.
  3. This pressure washer’s high-pressure pump is equipped with an adjustable unloader feature that allows the pressure setting to be adjusted. To lower the pressure, turn the pressure control knob on the pump counterclockwise to the desired pressure. To return the pump pressure to the factory setting, turn the pressure control knob on the pump clockwise until it stops.
  • NOTICE: DO NOT try to tum pressure regulator knob past the built-in stop or damage to the pump will result.
  • NOTICE: DO NOT overtighten the pressure control knob. If overtightened the knob COULD break and result in immediate loss of water pressure and costly repairs to the unit.
  • NOTICE: DO NOT attempt to increase pump pressure. A higher pressure setting than the factory set pressure may damage the pump. ****

Spray Wand Nozzles (Fig. A, H)
The nozzles for the spray wand are stored in the nozzle holder  2  on panel assembly  1. Colors on the panel identify the nozzle location and spray pattern. Refer to the following chart to choose the correct nozzle for the job to be performed.

DeWalt-3400-Gas-Pressure-Washer-fig- \(24\)

NOTICE:
The high-pressure spray from your pressure washer is capable of causing damage to surfaces such as wood, glass, automobile paint, auto striping and trim, and delicate objects such as flowers and shrubs. Before spraying, check the item to be cleaned to assure yourself that it is strong enough to resist damage from the force of the spray.

Changing Nozzles on Spray Wand (Fig. H)

  • DANGER: Risk of fluid injection. Do not direct discharge stream toward persons, unprotected skin, eyes, or any pets or animals. A serious injury will occur.
  • WARNING: Flying objects could cause a risk of serious injury. Do Not attempt to change nozzles while the pressure washer is running. Turn the engine off before changing nozzles.
  1. Pull the quick-connect coupler back and insert a nozzle.
  2. Release the quick-connect coupler and twist the nozzle to make sure it is secure in the coupler.
    • WARNING: Flying objects could cause a risk of serious injury. Ensure the nozzle is completely inserted in the quick-connect socket and the quick-connect collar is fully engaged (forward) before squeezing gun trigger.
Chemicals and Cleaning Solvents

Applying chemicals or cleaning solvents is a low-pressure operation.

NOTE:
Use only soaps and chemicals designed for pressure washer use. Do not use bleach.

To Apply Chemicals and Solvents (Fig. I)

  1. Press chemical hose  19  onto the barbed fitting located near high pressure hose connection of the pump as shown.
  2. Place the other end of the chemical hose with the filter into the container holding the chemical/cleaning solution. NOTE: For every 10 gallons (38 liters) of water pumped 1 gallon (3.8 liters) of chemical/cleaning solution will be used.
  3. Install low-pressure (black) nozzle into quick connect fitting of spray wand, refer to Spray Wand Nozzles. NOTE: Chemicals and soaps will not siphon if the black soap nozzle is not installed on the spray wand.
  4. After the use of chemicals, place the chemical hose into a container of clean water and draw clean water through the chemical injection system to rinse the system thoroughly
    NOTICE: Risk of property damage. Failure to do so could cause damage to the pump. Pumps damaged due to chemicals will not be covered under warranty.

Starting

  • WARNING: To reduce the risk of injury, read the pressure washer instruction manual and the engine instruction manual before starting the pressure washer.
  • DANGER: Risk of fluid injection and laceration. When using the high-pressure setting, DO NOT allow the high-pressure spray to come in contact with unprotected skin, eyes, or any pets or animals. A serious injury will occur.
    • Your washer operates at fluid pressures and velocities high enough to penetrate human and animal flesh, which could result in amputation or other serious injury. Leaks caused by loose fittings or worn or damaged hoses can result in injection injuries. DO NOT TREAT FLUID INJECTION AS A SIMPLE CUT! See a physician immediately!
  • DANGER: Carbon Monoxide. Using an engine indoors can kill you in minutes. Engine exhaust contains high levels of carbon monoxide (CO), a poisonous gas you cannot see or smell. You may be breathing CO even if you do not smell engine exhaust.
    • Breathing exhaust fumes will cause serious injury or death! Engine exhaust contains carbon monoxide, an odorless and deadly gas.
    • Operate pressure washers in a well-ventilated area. Avoid enclosed areas such as garages, basements, etc.
    • Never operate a unit in or near a location occupied by humans or animals.
  • WARNING: Risk of fire, asphyxiation, and burning. Never fill the fuel tank when the engine is running or hot. Do not smoke when filling the fuel tank.
    • Never fill the fuel tank completely. Fill the tank to 1/2″ (12.7 mm) below the bottom of the filler neck to provide space for fuel expansion. Wipe any fuel spillage from the engine and equipment before starting the engine.
    • DO NOT let hoses come in contact with a very hot engine muffler during or immediately after the use of your pressure washer. Damage to hoses from contact with hot engine surfaces will NOT be covered by warranty.
  • NOTICE: NEVER pull the water supply hose to move the pressure washer. This could damage the hose and/or pump inlet.
    • DO NOT use hot water, use cold water only.
    • Never turn the water supply off while the pressure washer engine is running or damage to the pump will result.
    • DO NOT stop spraying water for more than two minutes at a time. The pump operates in bypass mode when spray gun trigger is not pressed. When the temperature inside the pump rises too high the thermal relief valve ( 20, Fig. J) will open and release a gush of water in an effort to lower the temperature inside the pump. The thermal relief valve will then close. If the pump is left in bypass mode for more than two minutes internal components of the pump can be damaged.

Start-up Procedure (Fig. A, K–Q)

  1. In a well-ventilated outdoor area, add fresh, high-quality, unleaded gasoline with a pump octane rating of 86 or higher. Do not overfill. Wipe up spilled fuel before starting the engine. Refer to the engine instruction manual for the correct procedure.
    IMPORTANT: Ethanol Shield™ (sold separately) is a fuel stabilizer that helps eliminate and prevent ethanol-related problems in power equipment. Follow the instructions on the container and add to the gasoline.
    NOTICE: The use of fuels with greater than 10% ethanol is not approved for use in this product per EPA regulations and will damage the unit and void the warranty.

  2. Check engine oil level. Refer to the engine instruction manual for the correct procedure.

  3. Check pump oil level. The oil level should come to the dot in the middle of the sight glass. Refer to the Pump paragraph under Maintenance.

  4. Connect the water hose to the water source. Turn the water source on to remove all air from the hose. When a steady stream of water is present, turn the water source off.

  5. Verify the filter screen  21  is in the water inlet of the pump. The convex side faces out.
    NOTICE: Failure to use an inlet screen filter may cause damage to pump components and void warranty.DeWalt-3400-Gas-Pressure-Washer-fig-
\(29\)

  6. Connect the cold water source  22  to the pump inlet.

    • NOTE: Water source must provide a minimum of 5 gallons per minute at 20 psi (138 kPa).
    • WARNING: To reduce the possibility of contamination always protect against backflow when connected to a potable water system.
  7. Connect high-pressure hose  16  to the pump outlet.

  8. If applying a chemical or cleaning solution, refer to Chemicals and Cleaning Solvents.

  9. Turn the water source on.

    • NOTICE: Risk of property damage. Failure to do so could cause damage to the pump.
  10. Remove all air from the pump and high-pressure hose by depressing the trigger until a steady stream of water is present.

  11. Turn the engine ON/OFF switch  8  to the ON position.

  12. Place the fuel valve lever  13  in the ON position.

  13. If the engine is cold, move the choke 12 to the CLOSED position as shown.

    • WARNING: Risk of unsafe operation. Pull the starter grip slowly until resistance is felt. Then pull starter grip 9 rapidly to avoid kickback and prevent hand or arm injury.
    • NOTE: Do not allow the starter grip to snap back. Return it gently by hand. WARNING: Risk of unsafe operation. If the engine does not start after two pulls, squeeze the trigger of the gun to relieve pump pressure. Pull the starter cord slowly until resistance is felt. Then pull the cord rapidly to avoid kickback and prevent hand or arm injury.
    • NOTE: If the oil level in the engine is low, the engine will not start. If the engine does not start, check the oil level and add oil as needed.
  14. As the engine warms up, move the choke to the open position.

  15. Depress the trigger on the gun to start the water flow.

    • WARNING: Do not allow the unit to run for more than two minutes without the gun trigger being pulled. This could cause overheating and damage to the pump. When the temperature inside the pump rises too high, the thermal relief valve will open and release a spray of water from the pump to lower the internal temperature. The valve will then close.
    • WARNING: Risk of unsafe operation. Stand on a stable surface and grip the gun/wand firmly with both hands. Expect the gun to kick back when triggered.
  16. Release trigger to stop water flow. DANGER: Risk of injury from spray. Engage the trigger lock 24 when the gun is not in use to prevent accidental spraying.

  17. Adjust the spray for the task being performed by changing the quick-connect nozzle. Refer to Spray Wand Nozzles.

Shutting Down (Fig. R, S)

  1. If chemicals were applied, place the chemical hose into a container of clean water and draw clean water through the chemical injection system to rinse the system thoroughly.
    NOTICE: Risk of property damage Failure to do so could cause damage to the pump.

  2. Place the engine ON/OFF switch 8 in the OFF Position.

  3. Place the fuel valve lever 13 in the OFF position.

    • NOTICE: Risk of property damage. Never turn the water supply off while the pressure washer engine is running or damage to the pump will result.
  4. Turn the water source off.

  5. Pull the trigger on the spray gun to relieve any water pressure in the hose or spray gun.

  6. Refer to Storage for proper storage procedures.

MAINTENANCE

  • WARNING: Risk of burning. When performing maintenance, you may be exposed to hot surfaces, water pressure, or moving parts that can cause serious injury or death.
  • WARNING: Risk of fire. Always disconnect, the spark plug wire, let the engine cool, and release all water pressure before performing any maintenance or repair. The engine contains flammable fuel. Do not smoke or work near open flames while performing maintenance.

To ensure efficient operation and longer life of your pressure washer, a routine maintenance schedule should be prepared and followed. If the pressure washer is used in unusual conditions, such as high temperatures or dusty conditions, more frequent maintenance checks will be required.

Engine
Consult the engine instruction manual for the manufacturer’s recommendations for any and all maintenance.

NOTE:
The pressure washer frame is equipped with an oil drain hole to help make changing the engine oil easier.

Pump (Fig. T)

NOTE:
The Pump was filled with oil at the factory. The preferred oil is SIMPSON® Premium Pump Crankcase Oil. If this oil is not available, an SAE 15W-40 oil may be used. Change the pump oil after the first 50 hours of operation and every 100 hours thereafter, or every 3 months.

To Check Oil
The oil level should come to the dot in the middle of the sight glass 27.

How To Change Pump Oil

  1. Loosen pump oil fill plug 28.
  2. Place a container under the pump oil drain plug 29.
  3. Remove the pump oil drain plug.
  4. After the oil is drained, replace the pump oil drain plug. Tighten securely.
  5. Refill pump using SIMPSON® Premium Pump Crankcase Oil. If this oil is not available, an SAE 15W-40 oil may be used.
  6. Replace the pump oil fill plug and tighten it securely.

Nozzle Cleaning (Fig. U–V)
If the nozzle becomes clogged with foreign materials, such as dirt, excessive pressure may develop. If the nozzle becomes partially clogged or restricted, the pump pressure will pulsate. Clean the nozzle immediately using the nozzle kit supplied and the following instructions:

  1. Shut off the pressure washer and turn off the water supply.
  2. Pull the trigger on the gun handle to relieve any water pressure.
  3. Disconnect the spray wand from the gun.
  4. Remove the high-pressure nozzle from the spray wand. Remove any obstructions with the nozzle cleaning tool 25 provided and back flush with clean water.
  5. Direct water supply into spray nozzle to back flush loosened particles for 30 seconds.
  6. Reassemble the nozzle to the wand.
  7. Reconnect the spray wand to the gun then turn on the water supply.
  8. Start the pressure washer and place the spray wand into high pressure setting to test.

To Clean the Water Inlet Filter (Fig. K)
This filter screen 21 should be checked periodically and cleaned if necessary.

  1. Remove the filter screen 21 by grasping the end and removing it from the water inlet of the pump.
  2. Clean the filter by flushing it with water on both sides.
  3. Reinsert the filter into the water inlet of the pump. The Convex side faces out.

NOTE:
Do not operate the pressure washer without the filter properly installed.

STORAGE

Engine
Consult the engine instruction manual for the manufacturer’s recommendations for storage.

To Prevent Fuel-Related Problems

  1. Add Ethanol Shield™ fuel stabilizer following the manufacturer’s instructions. When adding a gasoline stabilizer, fill the fuel tank with fresh gasoline. If only partially filled, the air in the tank will promote fuel deterioration during storage. If you keep a container of gasoline for refueling, be sure that it contains only fresh gasoline.
  2. After adding a gasoline stabilizer, run the engine outdoors for 10 minutes to be sure that treated gasoline has replaced the untreated gasoline in the carburetor.
  3. Turn the fuel valve to the OFF position.
  4. Continue to run the engine until it stops from the lack of fuel in the carburetor fuel bowl. Running time should be less than 3 minutes.

Pump
The manufacturer recommends using SIMPSON®/POWERWASHER™ Pump Guard or equivalent when storing the unit for more than 30 days and/or when freezing temperatures are expected. SIMPSON® / POWERWASHER™ Pump Guard is environmentally friendly.

NOTE:
Using a pump guard helps provide proper lubrication to the internal seals of the pump regardless of temperature or environment.

NOTICE:
Risk of property damage. Use only SIMPSON®/POWERWASHER™ Pump Guard or equivalent. Other products could be corrosive and/or contain alcohol which may cause pump damage.

  1. Turn off the pressure washer and disconnect the hoses from the pump.
  2. Unscrew the bottle valve from the Pump Guard bottle and remove the seal.
  3. Screw the bottle valve back onto the bottle.
  4. Attach the bottle to the water inlet of the pump.
  5. Squeeze the bottle to inject contents into the pump.
  6. With the ignition switch off, simultaneously pull the starter rope and squeeze the bottle. Repeat until the protector fluid exits the pump outlet. NOTE: This step may require two people.

Pressure Washer

  1. Drain all water from the high-pressure hose, coil it, and store it in the cradle of the pressure washer handle.
  2. With the nozzle pointed down and the spray gun and wand in a vertical position, squeeze the trigger to drain all water from the spray gun and wand. Store in the gun holder.
  3. Store the chemical hose so it is protected from damage.
    • CAUTION: Risk of personal injury. Avoid placing hands between the handle and frame when assembling to prevent pinching.
    • NOTICE: Risk of property damage. Always store and transport the unit in an upright position.

ACCESSORIES

Recommended accessories for use with your tool are available for purchase from your local dealer or authorized service center. If you need assistance in locating any accessory for your tool, please contact the FNA Group at cservice@fna-group.com, 7152 99th Street Pleasant Prairie, WI 53158, or call 1–877–362–4271.

  • DANGER: Risk of fluid injection. When using replacement lances or guns with this pressure washer, do not use a lance and/or lance/gun combination that is shorter in length than what was provided with this pressure washer as measured from the nozzle end of the lance to the gun trigger.
  • WARNING: The use of any other accessory not recommended for use with this tool could be hazardous. Use only accessories rated equal to or higher than the rating of the pressure washer.

Service Information
Please have the following information available for all service calls:

  • Model Number ___
  • Serial Number _____
  • Date and Place of Purchase ____

Repairs
To assure product SAFETY and RELIABILITY, repairs, maintenance, and adjustment should be performed by an FNA factory service center, an FNA authorized service center, or other qualified service personnel. Always use identical replacement parts.

Limited Warranty

The manufacturer of this product agrees to repair or replace designated parts that prove defective within the warranty period listed below at the manufacturer’s sole discretion. Specific limitations/extensions and exclusions apply.
This warranty covers defects in material and workmanship and not parts failure due to normal wear, depreciation, abuse, accidental damage, negligence, improper use, maintenance, water quality, or storage. To make a claim under the terms of the warranty, all parts said to be defective must be retained and available for return upon request to a designated Warranty Service Center for warranty inspection. The judgments and decisions of the manufacturer concerning the validity of warranty claims are final.

These warranties pass through to the end user and are non-transferable. As a factory-authorized and trained Warranty Service Center, the factory will honor the terms of all component warranties and satisfy claims of the appropriate warranty provisions. Normal wear items include but are not limited to, valves and seals, which are not covered by this warranty.

This warranty replaces all other warranties, express or implied, including without limitation any warranties of merchantability or fitness for a particular purpose, and all such warranties are hereby disclaimed and excluded by the manufacturer. The manufacturer’s warranty obligation is limited to the repair and replacement of defective products as provided herein and the manufacturer shall not be liable for any further loss, damages, or expenses – including damages from shipping, accident, abuse, acts of God, misuse, or neglect. Neither is damage from repairs using parts not purchased from the manufacturer or alterations performed by non-factory authorized personnel. Failure to install and operate equipment according to the guidelines put forth in the instruction manual shall void the warranty.

This warranty does not cover the following:
Machines used for rental purposes, damage resulting from shipping (claims must be filed with freighter), accident, abuse, act of God, misuse, or neglect. Neither is damage from repairs or alterations performed by non-factory authorized personnel or failure to install and operate equipment according to the guidelines put forth in the instruction manual.
The manufacturer will not be liable to any persons
for consequential damage, for personal injury, or for commercial loss.

Responsibility of Original Purchaser (Initial User):

  • To process a warranty claim on your DEWALT pressure washer, report the concern to 1-877-362-4271 or cservice@fna-group.com for authorization and direction to the nearest authorized service center in your area.
  • Retain the original cash register sales receipt as proof of purchase for warranty work.
  • Use reasonable care in the operation and maintenance of the product as described in the Owners Manual(s).

Warranty Does Not Apply to Failures Due to:

  • Freight damage
  • Damage due to chemical deterioration, scale build-up, rust, corrosion, or thermal expansion
  • Freeze damage
  • Damage caused by parts or accessories not obtained from an authorized dealer or not approved by the manufacturer.
  • Normal wear of moving parts or components affected by moving parts.

Engine and Emissions Control System
Covered by engine manufacturer warranty. See engine manual.
High-Pressure Pump (defects in material and workmanship)
AAATM – Five (5) years from date of purchase

Frame (defects in material and workmanship)
Ten (10) years from date of purchase.

Accessories (Defects in Material and Workmanship)
Includes nozzles, hoses, spray guns, wands, tires, and feet Ninety (90) days from the date of purchase.

Glossary

  • Bypass mode: Allows water to re-circulate within the pump when the gun trigger is not pulled.
  • Chemical hose: Feeds cleaning agents into the pump to mix with the water. Refer to Chemicals and Cleaning Solvents.
  • Chemical injection system: Mixes cleaners or cleaning solvents with water to improve cleaning effectiveness. Choke control: Opens and closes carburetor choke valve.
  • CU: Cleaning Units. GPM multiplied by psi. (GPM x PSI = CU)
  • Fuel valve lever: Opens/closes connection between fuel tank and carburetor.
  • *GPM:** Gallons Per Minute. The unit of measure for the flow rate of water.
  • *PSI:* Pounds per Square Inch. The unit of measure for water pressure. Also used for air pressure, hydraulic pressure, etc. Complies with CETA Performance Standard CPC-100.
  • kPa (kilopascal): Metric pressure measurement. 1 kilopascal equal 1000 pascals.
  • Quick-connect spray wand: Allows the user to quickly change out high-pressure nozzles. Refer to Spray Wand Nozzles.
  • Thermal relief valve: When the temperature inside the pump rises too high the valve will open and release a gush of water in an effort to lower the temperature inside the pump. The valve will then close.
  • Water supply: All pressure washers must have a source of water. The minimum requirements for a water supply are 20 psi (138 kPa) and 5 gallons per minute.

Troubleshooting Guide

This section provides a list of the more frequently encountered malfunctions, their causes, and corrective actions. The operator or maintenance personnel can perform some corrective actions, and others may require the assistance of a qualified FNA technician or your dealer.

Problem Code
Engine will not start 1, 2, 3, 4, 5, 6, 7, 8, 36 (refer to the engine’s

instruction manual for further engine troubleshooting)
No or low pressure (initial use)| 9, 10, 11, 12, 13, 14, 15, 16
Will not draw chemicals| 16, 17, 18, 19, 20, 21
No or low pressure (after period of normal use)| 22, 23, 24
Water leaking at gun/spray wand connection| 25, 26
Water leaking at pump| 25, 26, 27, 28
Oil leaking at pump| 29, 30, 31, 32, 33, 34, 35
Pump Pulsates| 12

Troubleshooting Codes

CODE POSSIBLE CAUSE Po ssib le   solution
1 No fuel. Add fuel.
2 Low oil. Add required amount of oil.
3 Pressure builds up after two pulls on the recoil starter or after initial
use. Squeeze gun trigger to relieve pressure.
4 Choke lever in the NO CHOKE position. Move the choke to the CHOKE

position.
5| The spark plug wire is not attached.| Attach spark plug wire.
6| Engine ON/OFF switch in OFF position.| Place the engine ON/OFF switch in the ON position.
7| Choke lever in the CHOKE position on a hot engine or an engine that has been exposed to thermal heat for a long period of time.| Move choke to the NO CHOKE position.
8| Fuel valve CLOSED.| Move the fuel valve lever to the OPEN position.
9| Spray wand not in high pressure.| See spray Wand nozzles under Operation.
10| Low water supply.| Water supply must be at least 5 GPM @ 20 psi (138 kPa).
11| Leak at high-pressure hose fitting.| Repair leak. Apply sealant tape if necessary.
12| Nozzle obstructed.| See nozzle Cleaning under Maintenance.
13| The water filter screen is clogged.| Remove and clean the filter. See To Clean the Water Inlet Filter

under Maintenance.

14| Air in hose.| Turn off the engine, then the water source. Disconnect the water source from the pump inlet and turn the water source on to remove all air from the hose. When there is a steady stream of water present, turn the water source off. Reconnect the water source to the pump inlet and turn on the water source. Squeeze trigger to remove remaining air.
15| Choke lever in the CHOKE position.| Move choke to the NO CHOKE position.
16| High pressure hose is too long.| Use a high-pressure hose under 100 feet (30.48 m). Lengthen the water supply hose instead of the high-pressure hose.
17| Spray wand not in low pressure.| See spray Wand nozzles under Operation.
18| The chemical filter is clogged.| Clean filter.
19| The chemical screen not in the cleaning solution.| Make sure the end of the chemical hose is fully submerged in the cleaning solution.
20| Chemicals are too thick.| Dilute chemical. Chemicals should have the same consistency as water.
21| Worn seal or packing.| Have parts cleaned or replaced by the authorized service center.
22| The chemical build-up in the chemical injector.| Have replaced by an authorized service center.
23| Worn or obstructed valves.| Have replaced by the authorized service center.
24| Worn unloader piston.| Have replaced by the authorized service center.
25| Worn or broken o-ring.| Check and replace.
26| Loose hose connection.| Tighten.
27| Piston packings worn.| Have replaced by the authorized service center.
28| Pump head or tubes damaged from freezing.| Have replaced by the authorized service center.
29| Oil seals are worn.| Have replaced by an authorized service center
30| Loose drain plug.| Tighten.
31| Worn or torn drain plug o-ring.| Check and replace.
32| Worn or torn fill plug o-ring.| Check and replace.
33| Pump overfilled.| Check for the correct amount.
34| Incorrect oil used.| Drain and fill with the correct amount and type of oil.
35| The vent plug is clogged.| Clean the vent plug; blow air through it to remove any blockage. If the problem persists, replace the plug.
36| Air filter filled with oil.| Clean air filter element. Refer to the engine instruction manual for the correct procedure.

The FNA Group, Inc.,7152 99th Street Pleasant Prairie, WI 53158
(JUN18) Part No. 7110832 DXPW4240 Copyright © 2018

The following are trademarks for one or more DeWALT power tools: the yellow and black color scheme, the “D” shaped air intake grill, the array of pyramids on the handgrip, the kit box configuration, and the array of lozenge-shaped humps on the surface of the tool.

  • DeWALT®, GUARANTEED TOUGH ® and the yellow and black color scheme are trademarks of the DeWALT Industrial Tool Co., used under license.
  • SIMPSON® and AAATM are registered trademarks of the FNA Group, Inc.
  • The FNA Group, Inc.,7152 99th Street Pleasant Prairie, WI 53158, a licensee of DeWALT Industrial Tools

cservice@fna-group.com.

References

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