The Simpson 90037 AAA triplex plunger pump kit is the straightforward way to bring a tired gas pressure washer back to professional performance. Built for horizontal-shaft engines with a 3/4-inch shaft such as the Honda GX200, this fully plumbed replacement pump bolts on with common tools and delivers commercial-grade pressure with an industrial triplex design that far outlasts the axial cam pumps most consumer machines ship with.
Use Cases
- Replacing a worn or leaking OEM pump on a 3000 PSI class gas pressure washer
- Upgrading an axial cam machine to a longer-life industrial triplex pump
- Contractors keeping a spare pump kit so a pump failure never stops a job
- Fleet and rental shops standardizing on one field-replaceable pump platform
Specifications
The AAA triplex plunger pump is a direct drive horizontal pump rated at 3,400 PSI maximum pressure at 2.5 GPM maximum flow, with a forged brass manifold for strength and durability. It is designed with a gas engine flange and 3/4 in. hollow shaft that fits most horizontal shaft engines. All AAA pumps come pre-filled with oil and are equipped with thermal relief protection to prevent pump overheating. The threaded M22 pump outlet connects easily to the pressure hose, and the easy start feature makes startup simple. The crankcase is fully anodized die cast aluminum for corrosion protection and is sealed to prevent contamination and lube failure. A high performance double seal system prevents water leaks, dual oversized radial ball bearings improve wear and friction resistance, and precision ceramic coated pistons extend seal life. The oversized sight glass and advanced oil seal technology do away with the need for a dipstick. PowerBoost Technology enhances cleaning performance and reduces vibration and heat, extending engine and pump life.
- 3000 PSI class performance at 2.5 GPM
- M22 male outlet connector
- Adjustable unloader with easy-start system
- Sight glass oil monitoring - no dipstick needed
- Thermal relief protection prevents overheating
- Includes detergent injection siphon tube with filter, mounting bolts, and 3/16 in. shaft key
Frequently Asked Questions
Will the Simpson 90037 fit my pressure washer?
The 90037 fits gas pressure washers with a horizontal engine and a 3/4-inch diameter shaft, such as the Honda GX200. Its SAE bolt pattern, included hardware, and standard M22 connection make it a match for many brands of power washers.
What is the advantage of a triplex pump over an axial cam pump?
Triplex plunger pumps run cooler, are rebuildable, and typically last several times longer than the axial cam pumps found on consumer machines. For anyone using a pressure washer regularly, the triplex upgrade pays for itself in service life.
Does the pump come with oil?
Yes. All Simpson AAA pumps arrive pre-filled with oil, and the oversized sight glass lets you check the level at a glance without a dipstick.
What is included in the 90037 kit?
The kit includes the fully plumbed AAA triplex pump with adjustable unloader, a detergent injection siphon tube with filter, new mounting bolts, and a 3/16-inch shaft key.
Discount Cleaning Products is an authorized Simpson dealer with US-based customer service. Order genuine Simpson pressure washer pumps and parts with confidence.
