3681904 | Genuine Cummins® Air Brake Compressor

SKU: 3681904 MPN: 3681904

This new Cummins® Single cylinder air brake compressor is designed for commercial vehicles. Featuring part number 3681904, it offers water cooling and 145.0 psi max pressure. A direct fit for QSX15, QSB, ISB, ISX engines, meeting OEM specifications.

$1,279.00
No Core Charge
3 in stock

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Product Description

Product Name: Single Cylinder Air Brake Compressor Product Name: Single Cylinder Air Brake Compressor
Condition: New Condition: New
Brand: Cummins® Brand: Cummins®
Part Number: 3681904 Part Number: 3681904
Type: Single Cylinder Type: Single Cylinder
Suitable foe Engine:
QSX15 QSB ISB ISX QSX15 QSB ISB ISX
Specifications:
Weight: 44 lb Weight: 44 lb
Product category: Device Product category: Device
Calculated Volume (dm³): 21.155 Calculated Volume (dm³): 21.155
Cooling: Water Cooling: Water
Crankshaft thread: M20 x 1.5 Crankshaft thread: M20 x 1.5
Lubrication: Lubrication supplied from engine Lubrication: Lubrication supplied from engine
Max. operating pressure: 145.0 psi Max. operating pressure: 145.0 psi
Mounting: Mounting Flange Mounting: Mounting Flange
Operating speed: 3000 (1/min) Operating speed: 3000 (1/min)
Piston diameter: 3.35 in Piston diameter: 3.35 in
Piston stroke: 2.20 in Piston stroke: 2.20 in
Port thread 0: 0.81 in Port thread 0: 0.81 in
Port thread 2: M27 x 2 Port thread 2: M27 x 2
Port thread 4: M10 x 1.0 Port thread 4: M10 x 1.0
Port thread 8.1: Ø 0.36 in Port thread 8.1: Ø 0.36 in
Port thread 9: 3/4" - 16 UNF Port thread 9: 3/4" - 16 UNF
Port thread 9.1: 3/4" - 16 UNF Port thread 9.1: 3/4" - 16 UNF
Port thread 9.2: 3/4" - 16 UNF Port thread 9.2: 3/4" - 16 UNF
Swept volume (cm³): 318 cm3 Swept volume (cm³): 318 cm3
Temperature range: -30°C to +90°C Temperature range: -30°C to +90°C
Size (mm x mm x mm): 393.2 x 179.1 x 300.4 Size (mm x mm x mm): 393.2 x 179.1 x 300.4
Kit:
9111539422 Connecting Rod/Piston 9111539422 Connecting Rod/Piston
9111549292 Valve Plate/Gasket/Hexagon head screw ISO4017-M5x18 9111549292 Valve Plate/Gasket/Hexagon head screw ISO4017-M5x18
4111515002 Pressure valve 4111515002 Pressure valve
8107071574 Rolling bearing DIN625-6308 C3 8107071574 Rolling bearing DIN625-6308 C3
9111539252/ 9111536034 Flange/ Countersunk head screw DIN7991-M6x12/ Cover 9111539252/ 9111536034 Flange/ Countersunk head screw DIN7991-M6x12/ Cover
8977729084 O-Ring 8977729084 O-Ring
8950735894/ 9111539422 Cap 8950735894/ 9111539422 Cap

Useful Information

Description and Purpose:

The Cummins® Single Cylinder Air Brake Compressor (Part Number: 3681904) is a genuine replacement component engineered to meet OEM specifications. Specifically designed for QSX15, QSB, ISB, ISX engines, it features a water-cooled system, engine-supplied lubrication, and a durable flange mount. This unit is a direct fit, ensuring seamless integration into existing air brake systems.

Why Replacement is Important:

A functioning air compressor is critical for safe braking in commercial vehicles. Replacing the original unit with this OEM-matched part ensures that air pressure is properly maintained. Over time, wear and contamination can reduce efficiency—this compressor restores full system reliability without alterations.

Impact on Vehicle Performance:

With a maximum operating pressure of 145 psi and engineered for high rotational speed (3000 RPM), this compressor ensures steady air supply for optimal brake performance. The precise fit and matched specifications help maintain the vehicle’s original operational balance and safety standards.

Manufacturer Information:

Cummins® is globally recognized for its high-performance diesel engines and related components. As an OEM supplier, Cummins provides trusted, durable solutions designed to integrate seamlessly with commercial vehicle platforms, offering dependable operation in the most demanding environments.

Tags Category: Air Brake Compressor, Compressor, Brake System, Pneumatic System, Air System, Air Compression, Pneumatic Component, Compressed Air, Air Brake System Component, Single Cylinder

Warranty

Parts Finder Q offers a 365-days warranty for all types of parts in any condition. The warranty applies exclusively to purchases made directly through our website (partsfinderq.com). Please note that purchases made through third-party platforms like eBay or Amazon are not covered by this warranty.

Customer Reviews

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D
David Brown
Just ordered it and picked it up same day from the warehouse

Super glad I found this part online.
Didn’t have to wait weeks for the dealer.
Just ordered it and picked it up same day from the warehouse.
Saved me a ton of time!!!

  • Icon Truck, Fast Delivery
    Free shipping over $199 Place an order today and receive it on Mar 6
  • Clock Icon
    Orders placed before 7-PM EST will ship same business day
  • Location icon, warehouse pickup point.
    Pickup available usually ready in 24 hours
  • Need it fast? We offer overnight shipping

    Contact us to check if overnight next-day delivery is available for your order - PN: 3681904