Air Compressor For Cummins ISL ISC S21435 3966521 3966521RX 3969110 5301094RX

Air Compressor for Cummins ISL ISC

This air compressor replaces OEM cross-reference numbers S21435, 3966521, 3966521RX, 3969110, and 5301094RX, delivering the compressed air your brake system and air-operated accessories depend on.

Overview

This air compressor is a direct-fit replacement for Cummins ISL and ISC diesel engines, supplying the constant air pressure needed to run air brakes and other pneumatic systems on medium and heavy-duty trucks. Built as an alternative to the listed OEM cross-reference numbers, it keeps your compressed air system working without a dealer-only price. It is a practical choice for fleet mechanics and owner-operators maintaining Cummins ISL ISC equipment.

Built For Performance

• Direct replacement for OEM cross-reference numbers S21435, 3966521, 3966521RX, 3969110, and 5301094RX
• Engineered for Cummins ISL and ISC diesel applications
• Cast housing and internal components built to withstand continuous duty cycles
• Designed to deliver consistent air pressure for brake and accessory systems
• Supports the air demand of heavy-duty truck pneumatic circuits

Fits These Machines

• for Cummins ISL engines requiring the listed cross-reference compressor
• for Cummins ISC engines requiring the listed cross-reference compressor

On-The-Job Use

• Air brake system charging on medium and heavy-duty trucks
• Fleet maintenance and compressor replacement service
• Air-operated accessory supply on commercial diesel vehicles
• Over-the-road repair for owner-operators

Specs At A Glance

Good To Know

Q: Does this compressor come with a core charge? A: Core charge policies vary by seller, so check the listing details before ordering to confirm whether a core return applies. A: Confirm your engine model and existing compressor number match the cross-references listed above.

Q: Will this fit a Cummins ISL and an ISC engine? A: It is listed for both ISL and ISC applications, but serial number variations exist, so verify your specific engine before purchase. A: Matching the OEM number on your old compressor is the surest way to confirm fit.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.