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Four Seasons 26040 A/C System O-Ring and Gasket Kit for 1996-2011 Freightliner Century Class
SKU: 120|26040
OE-grade replacement A/C System O-Ring and Gasket Kit for your Freightliner Century Class. Precision-engineered by Four Seasons for direct fit — no modifications needed.
Vehicle Specific
Check if this part fits your vehicle.
1-year warrantyAll parts covered
Secure checkoutSSL encrypted
Free returns30-day no hassle
Same-day shippingOrder before 3 PM EST
Verify fitment before purchase — please check the Fitment section below.
Key Specifications
- Brand: Four Seasons
- Manufacturer Part Number: 26040
- Part Type: A/C System O-Ring and Gasket Kit
- Condition: New
- Warranty: 1 Year
Vehicle Compatibility
Fits select vehicle applications. Please enter your vehicle or check the Fitment section below to confirm compatibility.
Help prevent refrigerant leaks with this Four Seasons A/C System O-Ring and Gasket Kit. Designed to create secure seals at system connection points, it helps maintain proper pressure and dependable air conditioning performance.
Why replace this part? Worn or damaged seals can allow refrigerant to escape and reduce overall system efficiency. Replacing them helps restore secure connections and maintain proper air conditioning performance.
Key Features & Benefits
- Leak prevention — Seals critical system connection points effectively.
- Durable materials — Resists wear, compression, and temperature variations.
- Complete set — Includes all necessary O-rings and gaskets for secure installation.
Product Overview
Build Quality & Materials
- Durable seals resist compression set and maintain a secure system connection.
- Engineered to withstand temperature variations and pressure fluctuations.
- Constructed for reliable performance across multiple service intervals.
Installation Notes
- Confirm correct seal size and application before installation.
- Clean mating surfaces to ensure proper sealing.
- Inspect connections after assembly to verify system integrity.
Why Choose Four Seasons?
Four Seasons is a trusted leader in climate control and engine cooling components, supplying automotive replacement parts designed to support reliable system operation and long-term performance. With decades of industry experience, Four Seasons focuses on practical engineering solutions that help maintain comfort, efficiency, and dependability across a wide range of vehicle applications.
- Specialized focus on HVAC and engine cooling systems.
- Engineering-driven designs developed for consistent system operation.
- Components built for durability under normal driving conditions.
- Trusted by professional technicians and installers for reliable aftermarket solutions.
Four Seasons Engineering Advantage
Four Seasons applies proven engineering practices and application-specific design standards to develop components that support proper system function, consistent performance, and long-term reliability. Each part is designed to meet the operational demands of automotive HVAC and cooling systems, helping maintain stable performance under normal operating conditions.
Shipping & Warranty
- Fast U.S. shipping from our warehouse on business days.
- Free returns if the part does not fit or you are not satisfied (see store policy for details).
- 1-year warranty on this part from date of purchase.
Product Information
Item Specifics (Technical)
- Description: O-Ring & Gasket A/C System Seal Kit
- Style: O-Ring & Gasket Kit
- Type: AC System Seal Kits
Interchange Part Numbers
- 1321431
- 26040
- 407866
- 921460
- MT3905
Fitment
Vehicle Compatibility
- Freightliner Cascadia
- 2008-2009 Freightliner Cascadia
- 2013-2016 Freightliner Cascadia
- Freightliner Century Class
- 1996-2011 Freightliner Century Class
- Freightliner Classic
- 2001-2002 Freightliner Classic
- 2004-2011 Freightliner Classic
- Freightliner Columbia
- 2000-2009 Freightliner Columbia
- Fitment TypeVehicle Specific
| Year | Make | Model | Submodel | Notes |
|---|---|---|---|---|
| 1996 | Freightliner | Century Class | C120 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 1997 | Freightliner | Century Class | C112 (10.3L L6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | C112 (10.8L L6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | C112 (12.0L -6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | C112 (12.0L 732cid -6 DIESEL) | |
| 1997 | Freightliner | Century Class | C120 (10.3L L6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | C120 (10.8L L6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | C120 (11.1L 677cid L6 DIESEL Turbo/Aftercooled) | |
| 1997 | Freightliner | Century Class | C120 (12.0L -6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | C120 (12.0L 732cid -6 DIESEL) | |
| 1997 | Freightliner | Century Class | C120 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 1997 | Freightliner | Century Class | C120 (14.0L 855cid L6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | C120 (14.6L 893cid L6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | CST112 (10.8L L6 DIESEL Turbocharged) | |
| 1997 | Freightliner | Century Class | CST112 (12.0L 732cid -6 DIESEL) | |
| 1998 | Freightliner | Century Class | C112 (10.3L L6 DIESEL Turbocharged) | |
| 1998 | Freightliner | Century Class | C112 (10.8L L6 DIESEL Turbocharged) | |
| 1998 | Freightliner | Century Class | C112 (12.0L -6 DIESEL Turbocharged) | |
| 1998 | Freightliner | Century Class | C112 (12.0L 732cid -6 DIESEL) | |
| 1998 | Freightliner | Century Class | C120 (--) | |
| 1998 | Freightliner | Century Class | C120 (10.3L L6 DIESEL Turbocharged) | |
| 1998 | Freightliner | Century Class | C120 (10.8L L6 DIESEL Turbocharged) | |
| 1998 | Freightliner | Century Class | C120 (11.1L 677cid L6 DIESEL Turbo/Aftercooled) | |
| 1998 | Freightliner | Century Class | C120 (12.0L -6 DIESEL Turbocharged) | |
| 1998 | Freightliner | Century Class | C120 (12.0L 732cid -6 DIESEL) | |
| 1998 | Freightliner | Century Class | C120 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 1998 | Freightliner | Century Class | C120 (14.0L 855cid L6 DIESEL Turbocharged) | |
| 1998 | Freightliner | Century Class | C120 (14.6L 893cid L6 DIESEL Turbocharged) | |
| 1998 | Freightliner | Century Class | C120 (8.5L L4 DIESEL Turbo/Aftercooled) | |
| 1999 | Freightliner | Century Class | C112 (--) | |
| 1999 | Freightliner | Century Class | C112 (10.3L L6 DIESEL Turbocharged) | |
| 1999 | Freightliner | Century Class | C112 (10.8L L6 DIESEL Turbocharged) | |
| 1999 | Freightliner | Century Class | C112 (12.0L -6 DIESEL Turbocharged) | |
| 1999 | Freightliner | Century Class | C120 (--) | |
| 1999 | Freightliner | Century Class | C120 (10.3L L6 DIESEL Turbocharged) | |
| 1999 | Freightliner | Century Class | C120 (10.8L L6 DIESEL Turbocharged) | |
| 1999 | Freightliner | Century Class | C120 (11.1L 677cid L6 DIESEL Turbo/Aftercooled) | |
| 1999 | Freightliner | Century Class | C120 (12.0L -6 DIESEL Turbocharged) | |
| 1999 | Freightliner | Century Class | C120 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 1999 | Freightliner | Century Class | C120 (14.0L 855cid L6 DIESEL Turbocharged) | |
| 1999 | Freightliner | Century Class | C120 (14.6L 893cid L6 DIESEL Turbocharged) | |
| 1999 | Freightliner | Century Class | C120 (15.0L -6 DIESEL) | |
| 2000 | Freightliner | Century Class | C112 (10.3L L6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Century Class | C112 (10.8L L6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Century Class | C112 (12.0L -6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Century Class | C120 (--) | |
| 2000 | Freightliner | Century Class | C120 (10.3L L6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Century Class | C120 (10.8L L6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Century Class | C120 (11.1L 677cid L6 DIESEL Turbo/Aftercooled) | |
| 2000 | Freightliner | Century Class | C120 (12.0L -6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Century Class | C120 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 2000 | Freightliner | Century Class | C120 (14.0L 855cid L6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Century Class | C120 (14.0L L6 DIESEL Turbo/Aftercooled) | |
| 2000 | Freightliner | Century Class | C120 (14.6L 893cid L6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Century Class | C120 (14.9L L6 DIESEL Turbocharged) | |
| 2000 | Freightliner | Columbia | 120 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 2000 | Freightliner | Columbia | 120 (14.6L 893cid L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | C112 (--) | |
| 2001 | Freightliner | Century Class | C112 (10.3L 629cid -6 DIESEL) | |
| 2001 | Freightliner | Century Class | C112 (10.3L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | C112 (10.8L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | C112 (12.0L -6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | C112 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 2001 | Freightliner | Century Class | C120 (--) | |
| 2001 | Freightliner | Century Class | C120 (11.1L 677cid L6 DIESEL Turbo/Aftercooled) | |
| 2001 | Freightliner | Century Class | C120 (12.0L -6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | C120 (12.0L 732cid -6 DIESEL) | |
| 2001 | Freightliner | Century Class | C120 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 2001 | Freightliner | Century Class | C120 (14.0L 855cid L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | C120 (14.6L 893cid L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | C120 (14.6L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | C120 (8.9L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST112 (10.3L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST112 (10.8L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST112 (12.0L -6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST112 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 2001 | Freightliner | Century Class | CST112 (12.8L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (10.3L 629cid -6 DIESEL) | |
| 2001 | Freightliner | Century Class | CST120 (10.3L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (10.8L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (12.0L -6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (12.0L 730cid -6 DIESEL) | |
| 2001 | Freightliner | Century Class | CST120 (12.0L 732cid -6 DIESEL) | |
| 2001 | Freightliner | Century Class | CST120 (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 2001 | Freightliner | Century Class | CST120 (12.8L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (14.0L 855cid L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (14.6L 893cid L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (14.6L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (15.8L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (3.9L L4 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (4.3L L4 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (7.2L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Century Class | CST120 (8.5L L4 DIESEL Turbo/Aftercooled) | |
| 2001 | Freightliner | Classic | Base (10.8L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Classic | Base (11.1L 677cid L6 DIESEL Turbo/Aftercooled) | |
| 2001 | Freightliner | Classic | Base (12.7L 774cid L6 DIESEL Turbo/Aftercooled) | |
| 2001 | Freightliner | Classic | Base (14.0L 855cid L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Columbia | 120 (--) | |
| 2001 | Freightliner | Columbia | 120 (10.3L L6 DIESEL Turbocharged) | |
| 2001 | Freightliner | Columbia | 120 (10.8L L6 DIESEL Turbocharged) |
There are more vehicles this part is compatible with. Check if it fits your vehicle.
- BrandFour Seasons
- ManufacturerFour Seasons
- MPN26040
- EAN00096361208520
- Fitment Typespecific
- Part DescriptionO-Ring & Gasket A/C System Seal Kit
- Part TypeA/C System O-Ring and Gasket Kit
- Interchange Part Number1321431; 26040; 407866; 921460; MT3905
- Mfr LabelAC System Seal Kit
- Short DescriptionAC System Seal Kit
Shipping Policy – DTautoparts
We ship all orders from our U.S. warehouses with USPS, UPS, or FedEx.
Processing Time
Orders placed before 3 PM EST ship the same day
Others ship next business day
Transit Time
Standard shipping: 2–5 business days
Expedited shipping: 1–3 business days (optional at checkout)
Shipping Rates
Free standard shipping on all orders
Expedited options available at checkout
Tracking
All orders include tracking information, emailed automatically once shipped.
Lost Packages
If a package is lost in transit, we will:
Start an investigation with the carrier
Resend the order or issue a full refund if confirmed lost
Incorrect Addresses
If the address is incorrect when the order ships:
Carrier may return the package
We can resend (buyer pays reship fee) or refund the order
Return Policy – DTautoparts
At DTautoparts, we want every customer to be fully satisfied with their purchase.
If an item does not fit your vehicle or you are not fully satisfied, we offer hassle-free returns.
Return Window
Returns accepted within 30 days of delivery.
Items must be returned in their original condition unless the item was defective or damaged on arrival.
Free Returns
If the part doesn’t fit, or arrives damaged, we provide a free return shipping label.
Customer-Responsibility Returns
(used, installed, incorrect item ordered, changed mind)
Buyer pays return shipping.
Item must be unused, uninstalled, and in original packaging.
Incorrect / Defective Parts
If the part is faulty, damaged, or the wrong item was sent:
We will provide a free return label
And issue a full refund OR send a replacement
Refund Time
Refunds are processed within 2–3 business days after the returned item is received and inspected.
Warranty
All parts sold by DTautoparts LLC are backed by a 1-year warranty.
What’s Covered
Manufacturing defects
Premature failure
Broken components not caused by external damage
What’s Not Covered
Normal wear and tear
Improper installation
Damage from accidents or abuse
Modified or altered parts
How to Request a Warranty Claim
Please contact us with:
Order number
Description of the issue
Photos or videos of the problem
We will:
Review the claim in 24–48 hours
Provide a replacement or refund if approved
Frequently Asked Questions
Does this part fit my vehicle?
Use the Year/Make/Model selector at the top of the page.
If unsure, contact us — we respond within minutes.
Is this part new or used?
All parts are brand-new, factory-fresh, and never used.
Does this include hardware?
If included, it will appear in the product images or description.
If not listed, assume hardware is not included.
What if the part doesn’t fit?
No problem — we offer free returns on items that do not fit your vehicle.
What warranty does this part come with?
Every part includes a 1-year warranty.
How fast do you ship?
Orders before 3 PM EST ship the same day.