---
product_id: 31524716
title: "AAA 90034 Horizontal Triplex Plunger Replacement Pressure Washer Pump Kit, 4400 PSI, 4.0 GPM, 1\" Shaft, Includes Hardware and Siphon Tube, for Industrial Gas Powered Machines, Black"
brand: "simpson"
price: "€ 740.71"
currency: EUR
in_stock: true
url: https://www.desertcart.it/products/31524716-aaa-90034-horizontal-triplex-plunger-replacement-pressure-washer-pump-kit
store_origin: IT
region: Italy
---

# 4.0 GPM flow rate 4400 PSI max pressure 1" shaft with SAE bolt pattern AAA 90034 Horizontal Triplex Plunger Replacement Pressure Washer Pump Kit, 4400 PSI, 4.0 GPM, 1" Shaft, Includes Hardware and Siphon Tube, for Industrial Gas Powered Machines, Black

**Brand:** simpson
**Price:** € 740.71
**Availability:** ✅ In Stock

## Summary

> ⚡ Upgrade your clean game with power and precision!

## Quick Answers

- **What is this?** AAA 90034 Horizontal Triplex Plunger Replacement Pressure Washer Pump Kit, 4400 PSI, 4.0 GPM, 1" Shaft, Includes Hardware and Siphon Tube, for Industrial Gas Powered Machines, Black by simpson
- **How much does it cost?** € 740.71 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.it](https://www.desertcart.it/products/31524716-aaa-90034-horizontal-triplex-plunger-replacement-pressure-washer-pump-kit)

## Best For

- simpson enthusiasts

## Why This Product

- Trusted simpson brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Universal SAE Compatibility:** Fits most horizontal gas pressure washers with a 1" shaft—easy swap, no hassle.
- • **Durable Dual Oversized Bearings:** Minimize friction and extend pump life in tough industrial conditions.
- • **Oil Sight Glass & Advanced Seal:** Instantly monitor oil health without guesswork or dipsticks.
- • **Standard Garden Hose & Quick Connect:** Seamlessly integrates with popular pressure washer hoses for versatile use.
- • **PowerBoost Technology for Peak Performance:** Delivers higher nozzle pressure for faster, deeper cleaning.

## Overview

The AAA 4400 PSI 4.0 GPM Replacement Pressure Washer Pump Kit is a robust, easy-to-install upgrade designed for gas pressure washers with horizontal engines and a 1" shaft. Featuring PowerBoost Technology, dual oversized bearings, and an oil sight glass, it delivers industrial-grade cleaning power while extending your equipment’s lifespan. Compatible with standard SAE bolt patterns and popular hose connections, this pump kit offers a professional-grade solution backed by a 5-year warranty.

## Description

Engineered to surpass expectations, the 90034 AAA Professional 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 GX390. This pump can produce up to 4400 PSI at 4.0 GPM. The 90034 is designed with dual oversized ball bearings to reduce friction and allow for long lasting performance in the toughest cleaning environments. The 90034 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 4400 PSI at 4.0 GPM to wash walls, sidewalks, vehicles, and more
- Compatibility: SAE standard bolt pattern fits many gas pressure washers with horizontal engines. To ensure compatibility, be sure to match engine orientation, PSI, GPM, engine shaft diameter, and current pump inlet and outlet connection
- Adjustable power: 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
- Standard Connections: This replacement pump features a garden hose inlet and quick connect high pressure hose outlet; Use it with many pressure washer hoses, including Simpson Armor 41114, 41096, 41115 or Simpson Monster 41113, 41028, 41030, 41032, 41034

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | SIMPSON |
| Color | Black |
| Material | Brass, Black Aluminum |
| Style | 4400 PSI at 4.0 GPM |
| Product Dimensions | 11.5"L x 11.5"W x 11"H |
| Power Source | Gasoline |
| Item Weight | 16 Pounds |
| Maximum Flow Rate | 4 Gallons Per Minute |
| Global Trade Identification Number | 00879399002335 |
| Manufacturer | simpson |
| UPC | 879399002335 |
| Part Number | 90034 |
| Item Weight | 16 pounds |
| Country of Origin | China |
| Item model number | 90034 |
| Is Discontinued By Manufacturer | No |
| Thickness | N/A Inches |
| Item Package Quantity | 1 |
| Measurement System | US |
| Included Components | Pump Kit |
| Batteries Included? | No |
| Batteries Required? | No |
| Warranty Description | 5 year warranty |

## Product Details

- **Brand:** SIMPSON
- **Color:** Black
- **Material:** Brass
- **Style:** 4400 PSI at 4.0 GPM
- **Product Dimensions:** 11.5"L x 11.5"W x 11"H
- **Power Source:** Gasoline
- **Item Weight:** 16 Pounds
- **Maximum Flow Rate:** 4 Gallons Per Minute
- **Voltage:** 120
- **Global Trade Identification Number:** 00879399002335

## Images

![AAA 90034 Horizontal Triplex Plunger Replacement Pressure Washer Pump Kit, 4400 PSI, 4.0 GPM, 1" Shaft, Includes Hardware and Siphon Tube, for Industrial Gas Powered Machines, Black - Image 1](https://m.media-amazon.com/images/I/71UfvYTtB6L.jpg)

## Questions & Answers

**Q: Que medida es el eje o el chaf**
A: 1 inch

**Q: I have a 13 hp Honda with 4000 psi 3.8gpm cat pump...will this pump mount with same bolt pattern?**
A: ABSOLUTELY, no problem. Perfect fit for the GX390, WELL WITHIN SPECS! Better pump choice is the AR RKV45G40HD-F24 4000psi @ 4.5 gpm OR Bertolini WMG 4043 4000psi @ 4.3 gpm ......both superior to the "tipple A" ....Although the "cat" is better quality than all the above in the 4000 @ 4.0 gpm, but pricey! Keep in mind, that when a "pressure washer manufacture" like DeWalt publish a given pressure, it's typically 8% above the actual pressure EVER achievable. The reason for this is a deceiving sales tactic that manufactures like DeWalt take advantage of. The ASTM guidelines on pressure washers allow for a 8%  in min/max operating pressures so the pressure washer manufacture (not the pump mfg) takes the MAX pressure the actual pump is capable of producing and multiply by .08 and round down to the next "whole number". The cat pump on you're machine is only capable in the neighborhood of 3800 psi. ANY of the above listed pumps will exceed the performance of your OEM equipment from De Fault!

**Q: Will this pull water from a tank?**
A: i use a water tank it' in a truck so it's higher than the pump gravity feed

**Q: Will this fit dxpw4035 dewalt pressure washer?**
A: Technically it would fit on the Honda Engine but this pump required a 13HO GX390 Engine and the DXPW4035 has a GX270 9HP engine.

The suggested replacement pump is the 90038 AAA Pump

Thank You

Allparts Equipment Technical Service Team

## Frequently Bought Together

- AAA 90034 Horizontal Triplex Plunger Replacement Pressure Washer Pump Kit, 4400 PSI, 4.0 GPM, 1" Shaft, Includes Hardware and Siphon Tube, for Industrial Gas Powered Machines, Black
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*Product available on Desertcart Italy*
*Store origin: IT*
*Last updated: 2026-03-01*