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

Part Number: 85.139.021B
Pump Model: EZ4040G
Pump Type: Triplex | Direct-Drive | Gas

Professional-Grade Triplex Pump for High-Demand Cleaning

The GP EZ4040G Pump Assembly is a heavy-duty, direct-drive triplex pump designed for contractors and professionals who demand long-lasting performance and serious cleaning power. Delivering 4,400 PSI at 4.2 GPM, this pump offers an ideal balance of pressure and flow for tough commercial, industrial, and fleet-washing applications.

Built by General Pump, one of the most trusted names in pressure washer pump technology, the EZ4040G features a brass manifold, ceramic plungers, and an external unloader for reliability, easy service, and long operating life. Backed by a 5-year warranty, it’s engineered for daily professional use.

Key Features

• High Output Performance
  Produces up to 4,400 PSI and 4.2 GPM for demanding cleaning tasks

• Triplex Plunger Design
  Smooth operation, reduced vibration, and extended service life

• Ceramic Plungers
  Superior heat resistance and durability under continuous high pressure

• Brass Manifold
  Corrosion-resistant, strong, and excellent for heat dissipation

• External Unloader (85.300.037)
  Easier pressure adjustment and simplified maintenance

• Adjustable Soap Injector (85.400.000)
  Controlled chemical application for enhanced cleaning effectiveness

• Thermal Relief Valve (85.300.023)
  Protects pump from overheating during bypass operation

• Direct-Drive Gas Configuration
  Designed for 1" horizontal shaft gas engines running at 3,450 RPM

Specifications

Built for Durability

Every component of the EZ4040G is engineered for long service life in harsh environments:

• Ceramic plungers resist wear and heat

• Brass manifold prevents corrosion and cracking

• External unloader allows easy servicing and replacement

• Heavy-duty construction with a solid 20 lb build

This pump is an excellent replacement pump for commercial pressure washers and professional gas units.

Maintenance & Serviceability

The EZ4040G is designed for easy upkeep to maximize pump life:

• Uses 14 oz of 30W non-detergent oil

• Simple oil checks and scheduled changes keep performance consistent

• Handles inlet water temperatures up to 165°F (74°C)

Typical Applications

• Construction Equipment Cleaning

• Fleet Washing (Trucks, Buses, Trailers)

• Agricultural Equipment & Machinery

• Industrial Degreasing & Washdown

• Commercial Property Maintenance

• Surface Preparation & Paint Removal