HYD4040 Hydraulic Drive Kit | Triplex Pump

HYD4040 | Hydraulic Motor Pump Drive Unit | 4.0 GPM 4000 PSI | Max-Pressure Compact

HYD4040 is the pressure specialist of the compact hydraulic class: an Annovi Reverberi RK-series drive unit delivering 4.0 GPM at up to 4000 PSI at 1450 RPM — a full thousand PSI beyond the workhorse 3000 PSI tier, from the same compact F38 close-couple footprint and the same modest hydraulic appetite. When the job is measured in what comes off the surface rather than how fast the surface gets wet, this is the unit the specification lands on.

Four-at-four-thousand is a duty point with a résumé. It is the classic surface-cleaner and flatwork spec — the pressure that lifts gum, tire marks, sealer, and years of embedded grime out of concrete that 3000 PSI machines only brighten. It strips failing paint and coatings for prep work, cuts graffiti without blasting media, and breaks baked-on grease off equipment that soaking never touches. The HYD4040 brings that capability to trucks, trailers, and machines as a hydraulic drive unit: no engine, no belts, no fuel, powered from the auxiliary circuit already on board.

HYD4040 Specifications

• SKU: HYD4040
• Configuration: Hydraulic drive unit — RK-class pump with close-coupled hydraulic motor (F38 interface)
• Pump: Annovi Reverberi RK-series high-pressure triplex plunger pump (228-series frame)
• Flow Rate: 4.0 GPM (15 L/min)
• Maximum Discharge Pressure: 4000 PSI (280 bar class)
• Rated Speed: 1450 RPM — never overspeed
• Pump Power Requirement: Approximately 10.5 HP at full duty
• Inlet Port: 1/2″ F
• Discharge Port: 3/8″ F
• Maximum Fluid Temperature: 140°F
• Pump Head: Brass, with one-piece ceramic plungers
• Drive Interface: F38 close-couple flange (SAE A 82.55)

Hydraulic Supply Requirements

Full 4.0 GPM at 4000 PSI performance calls for roughly 13 hydraulic horsepower — on the order of 8.2 GPM (31 L/min) of oil at approximately 2,750 PSI working pressure with the gear-motor pairing this frame runs. That sits comfortably inside standard skid steer auxiliaries, tractor remotes, and truck hydraulic systems: maximum-pressure output without maximum-circuit demands is precisely the point of the compact RK frame. Protect the motor with a relief set for its rating, route return oil short and filtered to tank, and provide oil cooling for continuous trigger-on duty — surface cleaning is exactly that. Call WSHPWR with your machine’s auxiliary flow and pressure and we will confirm the pairing before you order.

Where 4000 PSI Earns Its Keep

Cleaning speed on flatwork is set by pressure at the nozzle, not gallons on the ground: a surface cleaner runs at the pace its jets can lift soil from the pores of the concrete, and the jump from 3000 to 4000 PSI is the difference between two passes and one on stained pads, fuel islands, drive-throughs, and dumpster corrals. The same authority translates across the prep trades — coating removal, rust scale, form release, curing compound — where dwell time and chemicals otherwise fill the gap. Buyers whose work leans toward volume rinsing should look at the 8 GPM and 13 GPM tiers instead; the HYD4040 exists for the work where pressure is the product.

Direct-Drive Simplicity

The hydraulic motor mounts to the pump through AR’s F38 close-couple flange — one centerline, no belts, pulleys, guards, or field alignment, minimal side loading on bearings and seals, and output independent of the host machine’s engine speed. Motor and pump dismount independently at the flange when service calls, and the unit installs as a bolt-down package in cabinets, tool compartments, and skids.

RK-Series Construction

The 228-series frame carries a corrosion-resistant brass head with stainless wet-end components, one-piece ceramic plungers for heat dissipation and abrasion resistance, and a die-cast aluminum crankcase with oil sight glass. Intake and delivery valves sit behind service plugs in the head for inspection without dismounting the HYD4040 — the same architecture and repair kits as every RK pump your shop already services.

Installation & Operation Notes

Mount horizontally and confirm motor rotation at commissioning. Feed the 1/2″ inlet from a flooded, filtered supply with short, unrestricted plumbing. Fit an unloader set against working pressure, and rate every downstream component — hose, gun, surface cleaner, nozzles — for 4000 PSI with margin; hardware carried over from 3000 PSI systems must be verified, not assumed. Size nozzle orifices to 4.0 GPM at working pressure (orifices sized for lower-pressure machines will not regulate correctly here), hold 1450 RPM as the ceiling, and winterize before cold-weather storage.

Quality Assurance & Maintenance

Every HYD4040 ships factory-tested for flow rate, pressure stability, and vibration. Maintenance follows AR’s standard RK schedule — crankcase oil changes, seal inspection, periodic valve checks with AR repair kits — with seal condition deserving attention proportional to the 4000 PSI duty point.

HYD4040 Key Features & Applications

• 4.0 GPM at 4000 PSI, 1450 RPM — the maximum-pressure compact in the hydraulic drive class.
• The surface-cleaner spec: one-pass flatwork where 3000 PSI machines take two.
• Runs on ~8.2 GPM of oil (~13 hydraulic HP) — standard auxiliary circuits qualify.
• F38 close-couple direct drive — no belts, engines, or fuel on the skid.
• Brass head, ceramic plungers, and standard AR RK repair kits.
• Ideal for concrete and flatwork contractors, surface-cleaner rigs, graffiti and coating removal, fleet degreasing, and prep-trade trucks running chassis hydraulics.