The Simpson 90038 AAA Triplex Plunger Pump Kit restores a gas pressure washer to full output, delivering up to 3800 PSI at 3.5 GPM. Built for pressure-washing pros and equipment owners replacing a worn or failed pump, this fully plumbed kit mounts to horizontal-shaft gas engines with a 1-inch shaft, such as the Honda GX270, and gets you back to cleaning driveways, fleets, decks, and job sites without buying a whole new machine.
Use cases
This kit is the go-to fix when a pressure-washer pump loses pressure or leaks:
- Replacing a worn, leaking, or seized triplex pump on a gas pressure washer
- Upgrading a cold-water gas washer for heavy commercial and contractor cleaning
- Fleet, equipment, and truck washing at up to 3800 PSI and 3.5 GPM
- Restoring rental units and returning them to service quickly
- Concrete, sidewalk, fence, and building wash-down applications
Specifications
- Max pressure: 3800 PSI
- Flow: 3.5 GPM
- Engine fit: Horizontal-shaft gas engine, 1-inch shaft (e.g. Honda GX270)
- Unloader: Stainless steel integrated unloader, adjustable
- Technology: PowerBoost for higher pressure at the nozzle
- Protection: Thermal relief protection, advanced oil seals
- Crankcase: Anodized die-cast aluminum
- Model: 90038 (previously 90032)
Frequently asked questions
What engine does the 90038 pump fit?
It fits horizontal-shaft gas engines with a 1-inch diameter shaft, such as the Honda GX270. Confirm your engine shaft size and mounting pattern before ordering.
What pressure and flow does it deliver?
Up to 3800 PSI at 3.5 GPM, making it suitable for demanding commercial and contractor cleaning.
Is it fully plumbed?
Yes. The kit comes fully plumbed with an integrated stainless steel unloader and easy-start system to simplify installation.
What is PowerBoost?
PowerBoost technology helps generate higher pressure at the spray nozzle so pressure is not lost as water travels through the system.
Discount Cleaning Products is an authorized dealer with US-based customer service to help you match the right part or accessory to your machine. Have a question about fit or compatibility? Our team can help before you order.
