When a gas pressure washer starts losing pressure, dripping oil, or stalling under load, the pump is usually the first place to look — and for many homeowners and contractors, replacing the pump outright is faster and more reliable than hunting down individual seals and o-rings for a rebuild. The Simpson OEM Technologies 90027 Vertical Axial Cam Pump Kit is a direct-fit replacement pump built for cold-water gas pressure washers with horizontal engines and a 7/8-inch shaft, delivering up to 3300 PSI at 2.4 GPM.
Built For
- Homeowners replacing a worn or leaking pump on a residential gas pressure washer
- Rental yards and equipment fleets standardizing on a reliable OEM-spec replacement pump
- Contractors and detailers who need the washer back in service the same day rather than waiting on individual rebuild parts
- DIY repair jobs where locating discontinued seal kits for the original pump has become impractical
The pump uses stainless steel pistons for longer seal life and pairs them with double high-pressure seals and a stainless steel integrated unloader with an easy-start system, which reduces starting load on the engine. A garden hose inlet and threaded M22 male outlet connection make plumbing straightforward, and the pump ships fully assembled with a brass manifold, siphon tube, and mounting hardware included.
Specifications
| Maximum Pressure | 3300 PSI |
| Flow Rate | 2.4 GPM |
| Shaft Size | 7/8-inch |
| Configuration | Vertical axial cam pump |
| Inlet | Garden hose connection |
| Outlet | M22 male threaded |
| Included Hardware | Brass manifold, siphon tube, mounting hardware |
Frequently Asked Questions
Will this pump fit my pressure washer?
The 90027 is designed to fit most cold-water gas pressure washers that use a horizontal engine and a 7/8-inch pump shaft, regardless of brand, as long as the mounting pattern and shaft size match.
Is it better to rebuild my old pump or replace it with this kit?
For many older or off-brand pumps, sourcing the correct o-rings and seal kits can be difficult and the parts cost can approach the price of a new pump. A direct-fit replacement like the 90027 avoids that search and restores full pressure and flow in one step.
Does this pump include the unloader valve?
Yes. The 90027 has a stainless steel integrated unloader with an easy-start system built in, so no separate unloader purchase is needed.
What is the warranty on this pump?
The Simpson OEM Technologies 90027 pump kit carries a 1-year limited manufacturer warranty.
Can I use this pump with hot water?
No. This is a cold-water rated axial cam pump and is not designed for hot water or steam pressure washer applications.
Discount Cleaning Products is an authorized dealer of Simpson OEM Technologies pumps and parts, backed by US-based customer service for order and fitment questions.
