CSF 3955 Radiator

Brand CSF 3955
Core Thickness 7/8
Core Width 14 5/8
Core Material Aluminum
Tank Material Plastic
Core Length 26 3/4
Inlet Diameter 1 5/16 left
Outlet Diameter 1 1/2 right
Down Flow Or Cross Flow Type Cross flow
Box Height (in) 6 1/16
Box Length (in) 36 3/16
Box Weight (lbs) 9
Box Width (in) 19
Hazardous Material No
Inlet Length (in) 15 7/16
Inlet Width (in) 1 5/16
No. Of Rows 1
Oil Cooler (in) No
Outlet Length (in) 15 7/16
Outlet Width (in) 1 5/16
Radiator Cap Supplied No
Tech Note O.e.m. style plastic tank & aluminum core with quick-connect outl
Fits Buick and Chevrolet · 13 vehicles

Heavy-duty core. 10% thicker than OEM for improved cooling capacity.

Aluminum core. Lightweight construction helps shed heat efficiently.

Cross-flow design. Optimized for steady coolant flow across the radiator.

Cross-references Dorman - HELP 13909, 42768667 and 42771761 for the same application. See all 4.

$146.19Free shipping
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Free returns within 60 days if it doesn't fit when fitment is verified.

OE-Style Radiator for Encore GX and Trailblazer

CSF 3955 is a cross flow radiator built with an aluminum core and plastic tanks in an OE-style layout. It is engineered for 2020-2026 Buick Encore GX and 2021-2026 Chevrolet Trailblazer applications, with an upgraded heavy-duty core that is 10% thicker than the OEM 20 mm design.

Key Features

  • Aluminum core with plastic tank construction
  • Cross flow design for the listed GM applications
  • Upgraded heavy-duty core thickness: 22 mm versus OEM 20 mm
  • Quick-connect outlet pipe design
  • Single-row core configuration
  • Inlet: 1 5/16 in. left; outlet: 1 1/2 in. right
  • CSF part number 3955

Detailed Description

CSF 3955 is a replacement radiator engineered for direct-fit service on the Buick Encore GX and Chevrolet Trailblazer. It uses an OE-style plastic tank and aluminum core construction, with a cross flow layout and a quick-connect outlet pipe to match the factory-style cooling system design. CSF states that its radiators are manufactured to high-performance standards, wind tunnel tested for cooling validation, and produced in ISO/TSO-certified facilities. This part cross-references Dorman - HELP 13909 for the same application.

What This Radiator Helps Address

  • Cooling system leaks from a damaged or aging radiator
  • Restricted coolant flow caused by internal core deterioration
  • Overheating concerns related to reduced heat transfer
  • Replacement needs after impact damage or tank failure
  • Service replacement for a worn OE-style radiator assembly

Installation Notes and Tips

Verify inlet and outlet orientation before installation: inlet is 1 5/16 in. on the left and outlet is 1 1/2 in. on the right. Confirm the vehicle uses the listed cross flow configuration and quick-connect outlet pipe arrangement. This radiator does not include a radiator cap. For fitment, use CSF 3955 on 2020-2026 Buick Encore GX and 2021-2026 Chevrolet Trailblazer, with the upgraded heavy-duty core specification noted for both applications.

Quality Assurance

CSF has supplied radiators worldwide for more than 50 years and reports over 30 million units sold. The brand also notes ISO/TSO-certified manufacturing and laboratory wind tunnel testing for cooling performance validation. Part number 3955 is built to support the listed GM fitments with an OE-style construction and upgraded core thickness.

This part fits 13 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelLitersCylindersPositionNotes
2026BuickEncore GX1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2026ChevroletTrailblazer1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2025BuickEncore GX1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2025ChevroletTrailblazer1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2024BuickEncore GX1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2024ChevroletTrailblazer1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2023BuickEncore GX1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2023ChevroletTrailblazer1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2022BuickEncore GX1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2022ChevroletTrailblazer1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2021BuickEncore GX1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2021ChevroletTrailblazer1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
2020BuickEncore GX1.3LL3N/AUpgraded Heavy Duty Core. 10% Thicker 22mm vs OEM 20mm
Directly replaces or cross-references 4 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Dorman - HELP — 139094276866742771761GM3010635