Part Number: 2278
Category: Pressure Washer Parts → Pump Repair Kits → Packing & Water Seal Kits
Type: AR 2278 Water Seal Kit – 20mm for XW-M Pressure Washer Pumps

The AR 2278 Water Seal Kit (Part #2278) is a genuine OEM packing and water seal repair kit designed for servicing compatible AR North America XWM Series triplex plunger pumps. Engineered with 20 mm sealing components, this complete rebuild kit includes the essential gaskets, front piston guides, and O-rings required to restore proper sealing performance and maintain reliable pump operation.

Key Features & Benefits

• Genuine AR North America OEM water seal kit
• Part Number: 2278
• Complete packing and water seal repair kit
• Designed for 20 mm XWM Series pumps
• Includes genuine OEM gaskets, piston guides, and O-rings
• Restores proper sealing performance
• Helps eliminate water leakage
• Maintains pump pressure and efficiency
• Ideal for pump rebuilds and preventive maintenance
• OEM-quality fit and long service life

Kit Contents

The AR 2278 Water Seal Kit includes:

• (3) AR1940440 – Gaskets
• (3) AR1940430 – Front Piston Guides
• (3) AR840280 – Gaskets
• (3) AR820490 – O-Rings

All components are genuine OEM AR North America replacement parts.

Technical Specifications

Part Number: 2278

Product Type: Packing & Water Seal Kit

Manufacturer: AR North America

Seal Size: 20 mm

Pump Series: XWM Series

OEM Replacement: Yes

Compatible Pump Models

Designed for use with compatible AR North America XWM Series pumps, including:

• XWM1530N
• XWM2128N
• XWM2623N
• XW3025N
• XWAM4G40N
• XWAM55G40N
• XWAM7G40N
• XWAM8G35N

Always verify your pump model before ordering.

Function of the Water Seal Kit

The water seal kit helps:

• Restore proper sealing around the pump plungers
• Prevent water leakage
• Maintain operating pressure
• Protect internal pump components from water bypass
• Improve pump efficiency
• Extend pump service life

Replacing worn sealing components helps maintain peak pump performance while reducing the risk of costly internal damage.

Common Signs Replacement Is Needed

Replace the water seal kit if you notice:

• Water leaking from the pump manifold
• Reduced operating pressure
• Decreased water flow
• Worn or damaged seals
• Cracked or flattened O-rings
• Pump rebuild or scheduled preventive maintenance

Replacing worn seals early helps prevent damage to ceramic plungers, manifolds, and other internal pump components.

Installation & Service Notes

• Shut down the pressure washer and relieve all system pressure.
• Remove the pump manifold according to the manufacturer's service procedures.
• Remove all worn seals, piston guides, gaskets, and O-rings.
• Clean all sealing surfaces thoroughly.
• Inspect ceramic plungers and replace any damaged components.
• Lubricate new seals and O-rings before installation.
• Install all components in the proper orientation.
• Reassemble the pump and verify leak-free operation.

Important: Inspect plungers, valve assemblies, and additional sealing components during service. Replacing worn components together helps maximize pump reliability and longevity.

Maintenance Recommendations

• Inspect packing and water seals during routine maintenance.
• Replace worn seals at the first signs of leakage or pressure loss.
• Maintain clean inlet water using an appropriate filtration system.
• Never operate the pump without an adequate water supply.
• Use only genuine OEM AR North America replacement parts to maintain optimum pump performance, reliability, and long service life.