Porter-Cable 5140240-52 Air Compressor Piston Kit – Genuine OEM Replacement Oil-Free Compressor Piston Kit

Part Number: 5140240-52
Category: Air Compressor Parts → Pump Components → Piston Kits
Type: Porter-Cable 5140240-52 Air Compressor Piston Kit – Genuine OEM Replacement Oil-Free Compressor Piston Kit

The Porter-Cable 5140240-52 Air Compressor Piston Kit is a genuine OEM replacement piston assembly designed for compatible Porter-Cable oil-free air compressors. This complete piston kit restores compression by replacing worn internal pump components, helping the compressor build and maintain proper air pressure. Manufactured to original equipment specifications, it provides a direct-fit replacement for worn or damaged piston assemblies, improving efficiency and extending the service life of the compressor pump. This part replaces previous part numbers 5140186-75 and E103495.

Key Features & Benefits

• Part Number: 5140240-52
• Genuine OEM Porter-Cable replacement part
• Complete piston kit for oil-free air compressors
• Restores proper compression and air delivery
• Helps improve pressure build-up and pump efficiency
• Direct-fit OEM replacement
• Manufactured to original equipment specifications
• Replaces part numbers 5140186-75 and E103495

Technical Specifications

Part Number: 5140240-52

Manufacturer: Porter-Cable

Product Type: Air Compressor Piston Kit

Application: Oil-Free Air Compressor Pump

OEM Part: Yes

Quantity: Sold Individually

Replaces: 5140186-75, E103495

Compatible Applications

The Porter-Cable 5140240-52 Piston Kit fits compatible oil-free air compressors, including:

Porter-Cable

• PXCMF220VW – 20-Gallon Oil-Free Air Compressor
• PXCMF226VW – 20-Gallon Oil-Free Air Compressor

It also fits select Craftsman and Husky oil-free air compressors that utilize the same OEM piston assembly, including models:

• Craftsman 921.166420
• Craftsman 921.169130
• Craftsman 921.169140

Always verify your compressor model, type number, and original part number before ordering to ensure proper compatibility.

Function of the Piston Kit

The 5140240-52 Piston Kit is designed to:

• Compress air within the pump cylinder
• Restore proper pressure generation
• Maintain efficient compressor operation
• Improve airflow and recovery time
• Replace worn piston and compression components
• Restore original factory pump performance

Using a genuine OEM replacement piston kit helps maintain dependable compressor performance and extends the life of the pump assembly.

Common Signs Replacement Is Needed

Replace the piston kit if you notice:

• Compressor runs but builds little or no pressure
• Longer-than-normal tank fill times
• Excessive air bypass inside the pump
• Reduced airflow from connected tools
• Worn or damaged piston components found during inspection
• Loss of compression due to piston or cylinder wear

A worn piston assembly can significantly reduce compressor efficiency and prevent the unit from reaching its rated operating pressure.

Installation & Service Notes

Disconnect the compressor from electrical power and completely drain all air pressure from the tank before servicing.

Remove the compressor shroud, cylinder head, and valve plate to access the pump assembly. Carefully remove the worn piston assembly from the connecting rod and cylinder. Inspect the cylinder sleeve, valve plate, reed valves, gaskets, and crankshaft bearing surfaces for wear or damage before installing the new 5140240-52 Piston Kit. Reassemble the pump using new seals and gaskets where required, ensuring all fasteners are tightened evenly to the manufacturer's specifications. After reassembly, test the compressor for proper pressure build-up and check for air leaks before returning it to service. Proper orientation of the valve plate is essential for correct compressor operation.

Important: Always verify your compressor model and original part number before ordering. If the cylinder sleeve, valve plate, or reed valves show excessive wear, inspect and replace those components as needed during the rebuild.

Maintenance Recommendations

• Keep the air intake filter clean to reduce pump wear.
• Drain condensation from the air tank after each use.
• Periodically inspect the pump for unusual noise or vibration.
• Replace worn valve plates and seals during major pump service.
• Avoid operating the compressor beyond its recommended duty cycle.
• Use genuine OEM replacement parts to maintain factory fit, proper compression, and long-term oil-free air compressor performance.