Skip to content
PRICE DEMOLITION SALE: Hundreds of Job-Crushing Deals. Shop Now >
Northern Tool Equipment Logo TextNorthern Tool Equipment Logo text link to Home.

Free Gift Card on All Orders Over $100 See Details

Extended - Last Chance!

Free Gift Card Details

$100 Order

$10
gift card

$250 Order

$25
gift card

$500 Order

$50
gift card

$1000 Order

$100
gift card
  • The promotion will be automatically applied on the Shopping Cart page.
  • To qualify for this offer, your order subtotal must equal $100 or more. Excludes gift cards, free item offers, warranties, Advantage memberships, tax and shipping.
  • Free gift cards will be issued in the form of e-gift cards only, not physical gift cards.
  • E-gift cards will be sent to the email address used in your billing address when your order ships or is picked up.
  • Free e-gift cards expire 11/01/26.
  • Promo code not valid on prior purchases or on Honda and STIHL products and cannot be combined with other promotional offers.
  • Valid online and in participating retail stores.
  • Limited-time offer. Subject to change without notice.
Print

Simpson Aluminum Cold Water Professional Gas Pressure Washer — 4200 PSI, 4.0 GPM, Honda GX390 Engine, CAT Pump, Model# ALH4240

Item# 6927579
Simpson Aluminum Cold Water Professional Gas Pressure Washer — 4200 PSI, 4.0 GPM, Honda GX390 Engine, CAT Pump, Model# ALH4240

This is a carousel with one large zoomable image and a track of thumbnails on the left. Select any of the thumbnail buttons to change the zoomable image on the right. If a thumbnail is a video or 360 degree image thumbnail, or the last thumbnail in the list, the button will open the product media modal.

Simpson Aluminum Cold Water Professional Gas Pressure Washer — 4200 PSI, 4.0 GPM, Honda GX390 Engine, CAT Pump, Model# ALH4240

Click or Tap image to Zoom

$1499.99

  • Shipping: 

    Factory shipped

    Heavy/large item. Lift gate service available.

  • Store Pickup: 

    Out of stock at Fredericksburg VA

  • HONDA® GX390 engine is equipped with a low oil shutdown feature
  • CAT PUMPS® triplex pump is equipped with an integrated unloader and thermal relief valve
  • Monster, 50 ft. dual braided high-pressure hose is kink and abrasion-resistant with a non-marring polyurethane outer jacket with QC fittings
  • Aluminum frame is crafted from high-grade aircraft aluminum, making it lightweight, durable, and corrosion-resistant
  • 5 Quick connect nozzle tips: 0°, 15°, 25°, 40° and soap nozzle to use for a variety of cleaning applications

  • Prop 65 Warning: See Details

See full description

Complete Your Solution

  • Simpson Aluminum Cold Water Professional Gas Pressure Washer — 4200 PSI, 4.0 GPM, Honda GX390 Engine, CAT Pump, Model# ALH4240
  • SIMPSON 3/8 in. x 50 ft. x 4500 PSI Cold Water Replacement/Extension Monster Hose
  • SIMPSON Turbo Nozzle up to 4500 PSI
  • SIMPSON Universal 20-Inch Industrial Pressure Washer Surface Cleaner- Hot or Cold Water Use - Rated up to 4500 PSI
Price for all four:

$2114.96

Frequently Bought Together

  • Description

  • Key Specs

  • Reviews

  • Q & A

  • Accessories

  • Warranty

  • Compare

Product Summary

Designed to meet the rigorous demands of the cleaning professional, the SIMPSON® Aluminum Series frame is crafted of aircraft-grade aluminum, making it lighter in weight than most steel frame pressure washer designs. Perfect for contractors who specialize in deck cleaning, wood restoration, paint preparation, graffiti removal, and all other professional cleaning services. The SIMPSON Aluminum Series designed for optimum performance in the harshest environments. Equipped with a premium (49-state compliant) HONDA® engine and reliable CAT PUMPS®  pump.

What's Included

    (1) Aluminum Gas Pressure Washer
Play Item Video

Features + Benefits

  • HONDA® GX390 engine is equipped with a low oil shutdown feature
  • CAT PUMPS® triplex pump is equipped with an integrated unloader and thermal relief valve
  • Monster, 50 ft. dual braided high-pressure hose is kink and abrasion-resistant with a non-marring polyurethane outer jacket with QC fittings
  • Aluminum frame is crafted from high-grade aircraft aluminum, making it lightweight, durable, and corrosion-resistant
  • 5 Quick connect nozzle tips: 0°, 15°, 25°, 40° and soap nozzle to use for a variety of cleaning applications

Key Specs

AttributeSpecification

item#

6927579

Brand

Simpson

Manufacturer's Warranty

1 year limited warranty

Ship Weight

325.0 LB

Pressure

4,200 PSI

Flow

4 GPM

Engine Brand

Honda

Engine Model

Gx390

Engine Displacement

389 cc

Fuel Type

Gasoline

Pump

CAT

Drive Style

Direct

CARB Compliant

No

Number of Tips Included

5
AttributeSpecification

Adjustable Pressure

Yes

Start Type

Recoil

Engine Oil Included

Yes

Engine Oil Type

10W-30

Fuel Capacity

1.61 Gal

Chemical Injector

Yes

Hose Length

50 ft

Nozzle Type

QC

Quick Connect Nozzle

Yes

Pump Oil Included

No

Low Oil Shutdown

Yes

Thermal Protector

Yes

Product Weight

133.0000 lb

Dimensions L x W x H (in.)

38.0 x 23.5 x 29.0 in

Reviews

Questions & Answers

251 Reviews This action will navigate to reviews.

Questions

1–2 of 2 Questions  
Sort by:

  1. Does this unit have a pick up tube for cleaning solutions such as bleach etc?

    1 answer

    1. The Simpson ALH4240’s downstream injector uses a soap pickup tube that connects to the pump’s barbed fitting and is limited to approved detergents, as the manufacturer explicitly prohibits bleach and all corrosive liquids.

      Helpful?

  2. I need to feed my power washer from a 275 water tank on a trailer What size water pump should I have to feed the power washer to maintain presure

    1 answer

    1. The pressure washer will put out 4 GPM and 4200 PSI. You would need a water pump that can put out a little higher flow rate for the GPM and at least provide 30-50 PSI to push the water to the pressure washer pump.

      Helpful?

Accessories We Recommend

This is a carousel with auto-rotating slides. Activate any of the buttons to disable rotation. Use Next and Previous buttons to navigate, or jump to a slide with the slide dots.

See All Pressure Washer Spray Tips + Nozzles
SIMPSON Turbo Nozzle up to 4500 PSI
0.0 out of 5 stars.

SIMPSON Turbo Nozzle up to 4500 PSI

Item # 7240509

$44.99

Warranty

Manufacturer's Warranty

1 year limited warranty

Recently Viewed Items

This is a carousel with auto-rotating slides. Activate any of the buttons to disable rotation. Use Next and Previous buttons to navigate, or jump to a slide with the slide dots.