Skip to Main Content

CAT Pumps 66DX40G1I Direct Drive Plunger Pump - 4 GPM, 4000 PSI

Mfr. Model #:
KR Part #:
26.40 lbs
Low Stock Warning
Now Only!

This 66DX40G1 direct drive plunger pump is a very popular model in the pressure washing sector. It includes a modular regulating unloader with built-in bypass ensures system pressure control and pump protection. The incorporated fixed chemical injector aids in cleaning flexibility. Operates at 4 GPM at 3400 RPM.


Technical Specifications

Max GPM: 4
Max PSI: 4000
Max Temperature: 140 degrees F
RPM: 3400
Shaft Diameter: 1 inch
Crankcase Capacity: 18 ounce
Bore: 14 millimeter
Inlet Port: 1/2 inch
Stroke: 11.4 millimeter

Product Description

66DX40G1 Pressure Wash Pump with Unloader and Injector

This 66DX Series direct-drive reciprocating plunger pump model 66DX40G1I has a brass manifold, 304 stainless steel valve assemblies, and solid ceramic plungers. It has a triplex design with three plunger rods. It comes standard with NBR (Buna-N) seals and O-rings. 

This model is very popular in the pressure wash industry. The flange-mount, hollow-shafted pump is designed to bolt directly to a gas engine drive for easy, compact installation. 

Dimensions: 11.73" x 10.51" x 8.15"


  • Maximum flow: 4 GPM
  • Pressure range: 100-4000 PSI
  • 3400 RPM
  • Direct drive

Compatible Parts and Accessories:

  • 6107 crankcase oil 
  • 6089 pressure gauge
  • 6011 pulsation dampener
  • 7104, 7203, 7204 inlet filters
  • 990840 flexible inlet hose
  • 990857 flexible discharge hose
  • 34334 oil drain kit
  • 6108 pressure washer pump protector
  • 33962 pop-off valve

Product Reviews

Frequently Asked Questions