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Product / Pressure Washers / 85.139.021B

GP EZ4040G Pump Assembly – 4.2 GPM, 4,400 PSI, 1" Shaft

GP EZ4040G Pump Assembly – 4.2 GPM, 4,400 PSI, 1" Shaft

Specifications

UNLOADER

External 85.300.037

WARRANTY

5 Years

RPM

3,450

PUMP MODEL

GP EZ4040G

PUMP TYPE

Triplex

Oil Type

30W Non Detergent

Oil Capacity

14 oz

Thermal Relief Value

85.300.023

Max Inlet Temperature

74°C / 165°F

Soap Injector

Adjustable 85.400.000

Discharge Size

3/8" Brass QC 85.300.108

Inlet Size

3/4" GHF

Plunger Piston

Ceramic

Unloader Type

External 85.300.037

Max GPM

4.2

Shaft Size

1"

Direct Drive

Gas

Weight

20 lbs

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PRODUCT

DESCRIPTION

Pro Triplex Pump for Heavy Duty Cleaning

The GP EZ4040G Pump Assembly (Bare Pump Part #85.130.021) is a professional triplex direct-drive gas pump for pros and contractors who need reliable, long lasting performance in high demand applications. With 4,400 PSI at 4.2 GPM this pump has cutting pressure and volume to tackle the toughest cleaning jobs.

Made by General Pump (GP) one of the most trusted names in pump technology the EZ4040G has a brass manifold, ceramic plungers and external unloader for years of trouble free operation. Backed by a 5 year warranty this pump is for contractors, industrial operators and serious users who need results.

Features

  • Bare Pump Part #: 85.130.021

  • Pump Manufacturer: General Pump (GP)

  • Pump Model: EZ4040G

  • Pump Style: Triplex, direct-drive gas

  • Max PSI: 4,400

  • Max GPM: 4.2

  • Shaft Size: 1" horizontal shaft

  • Unloader Type: External (85.300.037)

  • Plunger (Piston): Ceramic for maximum heat and wear resistance

  • Inlet Size: 3/4" GHF (garden hose fitting)

  • Discharge Size: 3/8" Brass QC (85.300.108)

  • Soap Injector: Adjustable (85.400.000)

  • Manifold Type: Brass

  • RPM: 3,450

  • Max Inlet Temp: 74°C / 165°F

  • Thermal Relief Valve: 85.300.023 included

  • Oil Capacity: 14 oz

  • Oil Type: 30W non-detergent oil

  • Weight: 20 lbs

  • Warranty: 5 Years

Built for Pro PowerThe triplex plunger design of the EZ4040G sets it apart from axial pumps with smoother operation, less vibration and longer life. Three ceramic plungers are engineered to handle high temp and abrasion for consistent high performance.

With 4,400 PSI and 4.2 GPM this pump has the best balance of raw cleaning power and coverage. It’s for demanding jobs like stripping paint, blasting oil and grease from heavy equipment, or fleet and construction cleaning.

Durable Construction

Every part of the EZ4040G is engineered for strength and long life:

  • Ceramic plungers for maximum durability under heavy use.

  • Brass manifold for corrosion resistance, strength and heat dissipation.

  • 1” horizontal shaft for compatibility with commercial grade gas engines.

At 20 lbs the EZ4040G is solidly built and easy to install making it a great replacement pump for professional pressure washers.

Operator Features

This pump has integrated features to make operation simple and efficient:

  • External unloader (85.300.037): Easy access and pressure regulation, simplifies maintenance and replacement.

  • Adjustable soap injector (85.400.000): Controlled application of detergents or chemicals for better cleaning.

  • Brass quick-connect discharge (3/8” – 85.300.108): Secure and leak free connections for hoses and accessories.

  • Thermal relief valve (85.300.023): Protects the pump from heat damage during extended bypass operation by purging overheated water.

Maintenance

The EZ4040G is designed for serviceability so operators can extend pump life with simple maintenance routines.

  • 14 oz of 30W non-detergent oil for lubrication.

  • Oil checks and scheduled changes keep the pump running smooth.

  • Designed to handle inlet water temp up to 165°F (74°C) for more versatility for jobs that use hot water.

These features make the EZ4040G good for everyday and high demand use.

Applications

The General Pump EZ4040G Pump Assembly is built for tough cleaning jobs across multiple industries. With high PSI and strong water volume it’s perfect for:* Construction Cleaning – Remove heavy mud, dirt and debris from equipment and job sites.

  • Fleet Washing – Wash buses, trucks, trailers and heavy duty vehicles with professional results.

  • Agriculture – Keep tractors, harvesters and farm equipment free from grime and buildup.

  • Commercial Property Maintenance – Clean large surfaces like parking lots, siding, walkways and patios.

  • Industrial Cleaning – Strip grease, oil and coatings from machinery and factory spaces.

  • Surface Preparation – Prepare surfaces for refinishing by blasting away paint, mold and buildup.

This pump has high output and rugged durability for professionals who demand results.

Product Details

  • Part#: 85.130.021

  • Manufacturer: General Pump (GP)

  • Model: EZ4040G

  • Style: Triplex, direct-drive gas

  • Max PSI: 4,400

  • Max GPM: 4.2

  • Shaft Size: 1” horizontal shaft

  • RPM: 3,450

  • Unloader: 85.300.037

  • Soap Injector: 85.400.000

  • Manifold Material: Brass

  • Plunger Material: Ceramic

  • Inlet Connection: 3/4” GHF

  • Discharge Connection: Brass QC 3/8" (85.300.108)

  • Oil Capacity: 14 oz (30W non-detergent oil)

  • Thermal Relief Valve: 85.300.023

  • Max Inlet Temp: 74°C / 165°F

  • Weight: 20 lbs

  • Warranty: 5 Years

General Pump Quality

General Pump is a world renowned company trusted for designing durable, reliable and efficient pumps. The EZ4040G Pump Assembly carries this reputation with triplex plunger design, brass manifold, ceramic plungers and external unloader for professional use.

Backed by a 5 year warranty this pump is a long term value and peace of mind for contractors and industrial users.For high pressure, high flow and tough use.

Frequently Asked Questions about Pressure Washers

How to store a pressure washer?

To ensure the durability of your heavy duty pressure washer:

  • Empty the gas tank to prevent fuel from degrading or clogging the engine.
  • Empty the pump and hoses of any remaining water.
  • Perform necessary maintenance before storage.
  • Store in a dry area.
  • Cover.

What is a pressure washer?

A power washer is a cleaning machine that uses a gasoline engine to power a high pressure water pump and nozzle. It’s used to clean driveways, decks, vehicles, outdoor furniture and more by spraying water at high PSI to remove dirt, grime, mold and other debris.Many models also come with a detergent tank for added cleaning power.

How does a power washer work?

A power washer works by drawing water from a connected hose and pumping it through a high pressure nozzle. The gas engine powers the pump which pressurizes the water and then expels it through the nozzle at high speed to clean the surface. The water pressure is measured in PSI (pounds per square inch) and the flow rate is measured in GPM (gallons per minute).Many models also feature adjustable water pressure settings to cater to different cleaning needs. BE makes pressure washing easy with models available for light jobs and heavy duty commercial cleaning projects.

Gas vs Electric power washers?

The main difference is that a gas pressure washer, known for its cleaning power, is powered by a gasoline engine, making it more powerful and portable, while an electric pressure washer is powered by electricity and is generally quieter and lighter.

Gas pressure washers are for heavy duty and large areas due to their durability, whereas electric pressure washers are for smaller jobs.

Your BE electric pressure washer is perfect for smaller jobs and built for portability, and we offer a wide range of electric models. Included with our electric models is a long extension cord for use anywhere around your house.

What to consider?

When choosing a gas pressure washer consider:

  • Pressure (PSI): More PSI means more cleaning power but also more potential for damaging delicate surfaces.
  • Flow Rate (GPM): More GPM means faster cleaning as more water is dispensed.
  • Engine Power: Bigger engines mean more durability and power.
  • Portability: Weight, handle design and wheel size for easier to move.
  • Nozzles: Multiple spray nozzles to adjust the spray pattern for different tasks.
  • Adjustable Nozzle: Allows for fine-tuning the spray intensity and pattern for various cleaning needs.

How much pressure do I need for?

The required pressure (PSI) and cleaning power depend on the surface you’re cleaning:

  • Light duty (car washing, outdoor furniture): 1,300-1,800 PSI.
  • Medium duty (patios, fences, decks): 2,000-3,000 PSI.
  • Heavy duty (driveways, brick walls, large equipment): 3,000+ PSI.

Many pressure washers come with adjustable pressure settings to handle different cleaning tasks effectively.

Can a pressure washing damage surfaces?

Yes, a power washer can damage surfaces if used incorrectly. High pressure water can strip paint, dent soft surfaces or even cause structural damage if the pressure is too high or the nozzle is held too close to the surface. Always use the right PSI for the material you’re cleaning and keep a safe distance from delicate surfaces.

To prevent damage, consider using a model with adjustable pressure settings.

How to maintain your pressure washer?

To ensure the durability and smooth operation of a pressure washer:

  • Change the oil as per manufacturer’s instructions.
  • Clean or replace the air filter to ensure good airflow.
  • Inspect and clean the nozzle regularly to prevent clogs.
  • Drain the gas tank if you’re storing the washer for a long time.
  • Check the hoses for leaks or damage and replace them if needed.
  • Follow regular maintenance requirements to keep the washer in optimal condition.

Can I use a pressure washer in cold weather and low water temperature?

You can use a pressure washer in cold weather but it’s more difficult. The water flow rate in the hoses and pump can freeze and damage the equipment. If you plan to use your pressure washer in cold temperatures make sure to winterize it and store it in a warm area when not in use. You can also use anti-freeze solutions for pressure washers.

Some models are designed to use hot water, which can be particularly effective for cleaning in cold weather.

Do I need any accessories?

Common accessories for power washers: