CAT 66DX40G1I Pump Assembly – 4.2 GPM, 4,400 PSI, 1" Shaft

Part Number: 85.119.025B
Pump Model: 66DX40G1I
Pump Type: Triplex | Direct-Drive | Gas

Heavy-Duty Triplex Pump for Professional & Industrial Use

The CAT 66DX40G1I Pump Assembly is a commercial-grade, direct-drive triplex pump engineered for professionals who demand maximum durability, reliability, and performance. Producing 4,400 PSI at 4.2 GPM, this pump is built to handle the toughest cleaning applications—from construction sites to fleet maintenance and industrial equipment washdown.

Manufactured by CAT Pumps, a global leader in high-pressure pump technology, the 66DX40G1I features a brass manifold, ceramic plungers, and an external unloader for long service life and easy maintenance. Backed by a 5-year warranty, this pump is built to perform day after day in demanding environments.

Key Features

• High-Output Performance
  Delivers up to 4,400 PSI and 4.2 GPM for serious commercial and industrial cleaning

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

• Ceramic Plungers
  Excellent heat resistance and wear durability under continuous high pressure

• Brass Manifold
  Superior corrosion resistance and efficient heat dissipation

• External Unloader (85.300.037)
  Easier pressure adjustment, servicing, and replacement compared to internal unloaders

• Adjustable Soap Injector (85.400.000)
  Controlled detergent application for improved cleaning efficiency

• Thermal Relief Valve (85.300.023)
  Protects pump during extended bypass operation by releasing overheated water

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

Specifications

Built for Durability

The CAT 66DX40G1I is engineered with premium materials to withstand harsh job-site conditions:

• Ceramic plungers resist heat and abrasion for extended service life

• Brass manifold protects seals and internal components from corrosion

• External unloader improves serviceability and long-term reliability

• 27-lb heavy-duty build ensures strength without complicating installation

This pump is an excellent replacement or upgrade pump for professional gas pressure washers.

Maintenance & Serviceability

Designed for easy upkeep to maximize pump longevity:

• Uses 18 oz of 30W non-detergent oil

• Simple oil checks and routine changes keep performance consistent

• Rated for inlet water temperatures up to 140°F (60°C)

Typical Applications

• Construction Equipment Cleaning

• Fleet Washing (Trucks, Buses, Trailers)

• Agricultural Equipment & Machinery

• Industrial Degreasing & Washdown

• Commercial Property Maintenance

• Surface Preparation & Coating Removal