W4443 4400 PSI Pump GX390 replaces EZ4040 RRV4G40

W4443 | Bertolini 4400 PSI 4.3 GPM Pump for GX390, 1 in. Hollow Shaft

W4443 is the base pump of WSHPWR’s Bertolini lineup, a WMG-series triplex piston pump rated 4.3 GPM at 4,400 PSI at 3450 RPM, built by Idromeccanica Bertolini in Reggio Emilia, Italy, where the company has made pumps since 1918. It bolts straight onto a GX390-class engine with a 1 in. shaft and SAE J609 mount, and replaces the stock pump on the most popular 4,000 to 4,400 PSI direct-drive machines.

Why 4,400 PSI, and why only here: Bertolini’s standard WMG is rated 4,000 PSI. This pump is built with stronger side bearings and upgraded bronze connecting rods, and Bertolini has granted it a 4,400 PSI rating exclusive to WSHPWR.com.

Which W4443 Do You Need?

The pump on this page is the bare pump. Each version below adds plumbing for a specific setup, using the same pump. If you want it plumbed and ready to run, choose the version built for your machine:

• • Bare pump (this page): no unloader. For shops that reuse their own unloader and plumbing.
  • W, WS and WP versions: built-in unloader and injector, with standard, socket quick connect or Pressure Pro outlet.

• VRT, VP and VPI versions: plumbed with a VRT unloader, Pressure Pro plug, and an injector on the VPI.
• T, WT, WST, WPT, VRTT and PIT versions: tank and gravity feed versions for trailers and skids.
• H, WH, HT and WHT versions: hot water versions with high-temperature seals.

What’s in the Box

• W4443 pump, fully assembled
• SAE J609 1 in. flange mounting bolts and lock washers
• Crankcase filled with Bertolini’s SynPower 75W-90 break-in oil
• Vented dipstick. Install it before the first start. Never run the pump without it.
• 7-year Bertolini warranty

Will It Fit My Machine?

The W4443 is a direct replacement for the pump on:

• Simpson SuperPro Roll-Cage SRC4440112
• BE Power Equipment B4415PCS
• Pressure-Pro E4040HA, E4042HV and SLPVV4G42-400
• Machines running Annovi Reverberi RKV4G36, RKV4G40 or RRV4G40 pumps

It fits any direct-drive pressure washer with a 1 in. horizontal engine shaft and SAE J609 mounting face, on a 389cc to 420cc engine (GX390 class). Inlet is 1/2 in. BSP and outlet is 3/8 in. BSP, so plan BSP fittings or adapters on NPT plumbing.

Not sure the W4443 fits? Text a pump specialist at (505) 226-6061 with a photo of your machine’s tag and we’ll confirm.

What Makes a Bertolini Different

• LowStressthread valve caps: the O-ring seals ahead of the thread, so pressure water never reaches it. The caps don’t loosen, need 40% less torque and put 60% less stress on the head.
• Lifetime oil: change the break-in oil once at 50 to 100 hours to standard 75W-90 gear oil, and that fill lasts the life of the pump.
• Built heavy: thick forged brass head, AISI 316 stainless check valves, solid ceramic plungers on nitrided stainless plunger rods, one-piece bronze connecting rods, oversized bearings and an extended forged steel crankshaft.

Common Questions

• Do I need a new unloader? It ships without one. Reuse yours if it is rated for 4,400 PSI and 4.3 GPM, or choose a plumbed version.
• Can it run hot water? The standard W4443 is rated to 140°F. For hotter water, choose an H version.
• How long does installation take? On a matching GX390-class machine it is a bolt-off, bolt-on swap.

W4443 Specifications

• Model: W4443 (Bertolini WMG series)
• Flow: 4.3 GPM at 3450 RPM
• Max Pressure: 4,400 PSI (WSHPWR exclusive rating)
• Shaft: 1 in. hollow
• Mount: SAE J609 1 in.
• Engine: 389cc to 420cc, GX390 class
• Inlet / Outlet: 1/2 in. BSP / 3/8 in. BSP
• Plungers: Solid ceramic, 15 mm
• Connecting Rods: Bronze, one-piece
• Check Valves: AISI 316 stainless steel
• Oil: 0.6 L SAE 75W-90
• Max Water Temperature: 140°F
• Weight: 17 lbs
• Warranty: 7 years
• Brand: Bertolini, made in Italy

Shipping: Usually ships via UPS in 1 to 3 days.