Part Number: RKA4G40HN
Category: Pressure Washer Pumps → Triplex Pumps → Belt Drive Pressure Washer Pumps
Type: AR RKA4G40HN Pressure Washer Pump – 4.0 GPM 4000 PSI 24mm Short Shaft 1" Inlet

The AR RKA4G40HN Pressure Washer Pump (Part #RKA4G40HN) is a genuine OEM triplex plunger pump engineered for demanding commercial and industrial pressure washing applications. Built by Annovi Reverberi (AR), this heavy-duty pump delivers 4.0 GPM at 4,000 PSI, providing exceptional cleaning performance for fleet washing, construction equipment, agriculture, manufacturing facilities, and other high-pressure cleaning operations.

Key Features & Benefits

• Genuine AR (Annovi Reverberi) OEM triplex pressure washer pump
• Part Number: RKA4G40HN
• Heavy-duty triplex plunger design
• Delivers up to 4.0 GPM at 4,000 PSI
• Low-speed 1,750 RPM operation for extended service life
• 24 mm short shaft configuration
• 1-inch water inlet
• Compatible with belt-drive and gear-drive systems
• Requires approximately 11 BHP
• Suitable for engines up to 14.5 GHP
• Smooth, efficient operation with reduced vibration
• Designed for continuous commercial and industrial use
• OEM-quality durability and performance

Technical Specifications

Part Number: RKA4G40HN

Pump Model: RKA4G40HN

Manufacturer: AR (Annovi Reverberi)

Product Type: Triplex Pressure Washer Pump

Maximum Flow Rate: 4.0 GPM

Maximum Pressure: 4,000 PSI

Maximum Pump Speed: 1,750 RPM

Brake Horsepower (BHP): 11

Gas Horsepower (GHP): 14.5

Shaft Size: 24 mm Short Shaft

Water Inlet: 1"

Weight: 19 lbs

OEM Replacement: Yes

Compatible Applications

Designed for use with compatible pressure washer systems featuring:

• 24 mm shaft drive systems
• Belt-drive pressure washers
• Gear-drive pressure washers
• Commercial pressure washers
• Industrial cleaning equipment
• Fleet washing systems
• Agricultural cleaning equipment
• Construction equipment cleaning
• OEM equipment replacement and custom builds

Always verify shaft dimensions, mounting configuration, horsepower requirements, and pressure/flow specifications before ordering.

Function of the Pressure Washer Pump

The RKA4G40HN pump helps:

• Deliver up to 4.0 GPM of water flow
• Generate operating pressures up to 4,000 PSI
• Provide reliable continuous-duty cleaning performance
• Operate efficiently at lower pump speeds
• Reduce heat buildup and internal wear
• Extend equipment service life in demanding applications

Its low-speed triplex plunger design provides superior durability, smoother operation, and longer service life than high-speed direct-drive pumps.

Common Signs Replacement Is Needed

Replace the pump if you notice:

• Reduced operating pressure
• Decreased water flow
• Water or oil leaks
• Excessive operating noise
• Cracked or damaged pump housing
• Excessive internal wear
• Loss of cleaning performance
• Pump failure during operation

Replacing a worn pump restores pressure washer performance while minimizing equipment downtime.

Installation & Service Notes

• Shut down the pressure washer and relieve all system pressure.
• Disconnect the engine or motor before servicing.
• Verify compatibility with the shaft size, mounting configuration, pulley alignment, and horsepower requirements.
• Install the pump according to the manufacturer's specifications.
• Fill the crankcase with the recommended pump oil before operation if required.
• Connect the water inlet and high-pressure discharge plumbing.
• Prime the pump with water before startup.
• Verify proper operation and inspect for leaks after installation.

Important: Never operate the pump without an adequate water supply. Running the pump dry can quickly damage the plungers, seals, and valves, significantly reducing pump service life.

Maintenance Recommendations

• Check the pump oil level regularly and change the oil according to AR maintenance intervals.
• Inspect packings, seals, valves, and fittings during routine service.
• Maintain clean, filtered inlet water to minimize internal wear.
• Check belt alignment and tension periodically on belt-drive systems.
• Use only genuine OEM AR replacement parts and approved lubricants to maintain optimum performance, reliability, and long service life.