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Pumps
AAA® Triplex Pump Kit 90039
4000 PSI at 3.5 GPM Industrial Triplex Pump Kit
Online Model No: 90039 (Part No: 90039)
In-Store Model No: 90039 (Part No: 90039)
Engineered to surpass expectations, the 90039 AAA® Triplex Pump is highly efficient and minimizes engine load while delivering top performance. This easy-to-install pump replacement kit is for gas pressure washers* with a horizontal engine and a 1″ diameter shaft, such as the Honda GX270. This pump can produce up to 4000 PSI at 3.5 GPM. The 90039 is designed with dual oversized ball bearings to reduce friction and allow for long lasting performance in the toughest cleaning environments. The 90039 features a stainless steel integrated unloader featuring our easy-start system.
*Check your pressure washer’s inlet and outlet orientation to ensure compatibility
Features
Extend the Life of Your Pressure Washer: Save money by replacing your pump instead of buying a whole new power washer. This easy-to-install kit is great for power washers that can support 4000 PSI at 3.5 GPM to wash walls, fences, sidewalks, vehicles, and more.
Easy Installation: This replacement pump features a garden hose inlet and QC quick connect high pressure hose outlet. The SAE standard bolt pattern that fits most* gas-powered pressure washers. Each kit includes a siphon tube with filter, mounting bolts, shaft key, and instruction booklet to get your machine back in action as quickly as possible.
Adjustable Power: This pump includes PowerBoost® Technology that delivers higher pressure at the nozzle for a more efficient cleaning experience. There is also a hand turn knob that lets you reduce power at your convenience for tasks that require lower pressure.
Know When to Change Your Oil: The sight glass and advanced oil seal technology eliminates the need for a dipstick. With visibility to the oil level and the oil itself, you can easily see when oil levels are low or if water has clouded the oil.
Get the Right Pump for Your Machine: This pump is designed for gas powered pressure washers with horizontal engines. Its SAE bolt pattern, hardware, and standard connections make it a great fit for many brands and models of power washers.
Images shown may vary from the actual unit
*Check your pressure washer’s inlet and outlet orientation to ensure compatibility
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Product Specs
- UPC (Online): 879399002090
- Power Type: Gasoline
- PSI: 4000
- GPM: 3.5
- Pump Brand: AAA
- Diameter: 1"
- Hose Diameter: 1"
- PowerBoost: Yes
- Head: Brass
- Pump: Black Aluminum
- Hose Diameter: 1"
- Frame: Sight glass and advanced oil seal technology, does away with the need for a dipstick
- Shaft Diameter: 1"
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Warranty
5 Year limited commercial pump warranty
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Reviews
KayakingWork great for 2 years or lessReviewed on May 1st, 2024I've had several of these pumps, never gotten more than 2 years. To get the warranty you have to bring them your machine and give them 2 weeks to decide if they will warranty it. If you're in business like me you can't afford to be without your machine for 2 plus weeks.
Response from SIMPSONHi, Kayaking. This isn't the experience we strive for at all. We are very sorry for the issues you have experienced; we would like to understand more about field service issues you have described. can you please contact our National Service Manager to help look further into these issues, he can be contacted at DHattan@fna-group.com. We truly appreciate the feedback and hope to be hearing from you!
Simpson TeamMay 3rd, 2024
WhatzupPump has run for less that 16 hours. There's 1/4 pound of brass shavings in the oilReviewed in US on July 10th, 2026Customer service was not only bad, the were deliberately adversarial and made EVERY effort they could to make it hard as they could to process a claim, and then insisted I drive 150 MILES to see somebody about it! Total misanthropes and hooligans! Let me show you all the bearing material in the oil pan! I can't believe this came from just one pump! This isn't even engine oil! It's ALL pump oil! I haven't even owned this for year & it has 16 hours on it! And Simpson Customer Service was totally nonchalant.
JF43One Unhappy CamperReviewed on June 2nd, 2025Age: 65 or over |Purchased from: Online |Very poor quality pump. This is my 3rd one. The original one had issues with the unloader valve. Luckily, it went out under warranty, and I took it to a service shop (once again, luckily), on the very last day of the warranty. I got it there on the last day of the warranty. The shop said it was a non-serviceable unloader, and the pump had to be replaced. This was done under warranty, and much to my satisfaction. The next time I used the machine, I noticed water in the pump's oil through the sight glass. I ordered the new seal replacement kit and installed it. After just a few minutes of operation with the new seals, water was in the pump yet again. Not wanting to destroy the machine, I ordered the replacement pump and installed it. After only several minutes of run time, I noticed the milky oil/ water mix through the sight glass once again. The engine on the machine is great, but these pumps fail miserably for me. I will look for a different brand of replacement pump to fit the 4000 # pressure washer with a Honda GX270 engine on it. Interestingly, I have done mechanical and maintenance work on engines, both large and small, as well as many types of pumps since childhood. I never leave water in the pumps when the machine is going to be stored for any amount of time, as I know what freezing will do to a pump. Also, leaving city tap water or mineral-filled well water for any amount of time eats the pumps up from the inside out.
Response from SIMPSONHi, JF43. Thanks for reaching out. We're sorry to hear about the unloader valve & glad you were able to replace the pump. The milky appearance of your pump oil is actually normal during operation as the oil becomes frothy from the high-speed operation of the pump. Within a few hours after shutting off the pressure washer, the air bubbles in the oil will start to dissipate, and the oil should return to its regular appearance. If this doesn't happen, please don’t hesitate to contact our team directly at 877-362-4271 or email us at productsupport@simpsoncleaning.com and we will be happy to assist with getting the issue resolved! Thanks for sharing your experience!
Simpson TeamJune 2nd, 2025
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