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Dorman M390257 Brake Master CylinderOE Quality 60-Day Returns
Part #: M390257

Dorman M390257 Brake Master Cylinder

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162 vehicles fit this part
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Fitment: Chevrolet, GMC, and Dodge, C2500, K2500, Tahoe, Yukon, C1500, C1500 Suburban, C2500 Suburban, K1500, K1500 Suburban, K2500 Suburban, Ram 1500, Ram 2500, and Blazer
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Reliable Brake Master Cylinder for Chevrolet, Dodge, and GMC Vehicles

The Dorman M390257 Brake Master Cylinder is engineered to restore proper brake hydraulics in select Chevrolet, Dodge, and GMC trucks and SUVs. Designed with an aluminum body and a 1.25-inch bore diameter, this master cylinder includes a reservoir and supports dual outlet connections for efficient brake fluid distribution.

  • Master cylinder bore diameter: 1.25 inches for precise hydraulic pressure
  • Durable aluminum construction for corrosion resistance
  • Includes reservoir for brake fluid storage
  • Two outlets with rearward outlet size 1/2-20 and secondary outlet thread diameter 9/16-18
  • Compatible with Chevrolet Blazer, C1500, C1500 Suburban, C2500, C2500 Suburban, K1500, K1500 Suburban, K2500, K2500 Suburban, GMC Yukon, Tahoe, and Dodge Ram 1500 and 2500 models
  • Mounting hardware not included

Product Details and Specifications

The Dorman M390257 brake master cylinder is constructed from aluminum, providing a lightweight yet durable component that resists corrosion and wear. Its 1.25-inch bore diameter ensures consistent hydraulic pressure for reliable braking performance. The included reservoir allows for proper brake fluid containment and circulation. This master cylinder features two outlets: a rearward outlet sized at 1/2-20 and a secondary outlet with a 9/16-18 thread diameter, accommodating the brake line connections required for the specified vehicle models. Note that mounting hardware is not included with this part.

Compatible Vehicles and Applications

This brake master cylinder is compatible with a range of Chevrolet, Dodge, and GMC trucks and SUVs, including:

  • Chevrolet Blazer, C1500, C1500 Suburban, C2500, C2500 Suburban, K1500, K1500 Suburban, K2500, K2500 Suburban
  • GMC Yukon and Tahoe
  • Dodge Ram 1500 and Ram 2500

It is designed to replace the original master cylinder in these models, ensuring proper brake system function and safety.

Common Issues Addressed by This Master Cylinder

  • Brake pedal sinking or sponginess due to internal leaks
  • Brake fluid leaks around the master cylinder area
  • Reduced braking efficiency or inconsistent brake pressure
  • Brake warning light activation related to master cylinder failure
  • Contaminated or damaged reservoir affecting brake fluid supply

Installation Notes and Tips

  • Ensure the brake system is properly bled after installation to remove air pockets
  • Verify compatibility with your specific vehicle model and year before installation
  • Use appropriate brake fluid as specified by the vehicle manufacturer
  • Mounting hardware is not included; reuse existing hardware or source separately
  • Inspect brake lines and fittings for wear or damage during installation

Quality Assurance and Warranty

Dorman parts are manufactured to meet or exceed OEM standards for fit, form, and function. The M390257 brake master cylinder undergoes rigorous quality control to ensure durability and reliable performance. Please refer to Dorman's warranty policy for specific coverage details.

BrandDorman
Part NumberM390257
Master Cylinder Bore Diameter1.25
Master Cylinder MaterialAluminum
Mounting Hardware IncludedNo
Number of Outlets2
Package ContentsMaster Cylinder
Rearward Outlet Size1/2-20
Reservoir IncludedYes
Secondary Outlet Thread Diameter9/16-18
Sensor IncludedNo

This part fits 162 vehicles. Search below:

YearMakeModelDrive TypeFuel TypePositionNotes
2000ChevroletC2500N/ABore size 1.25 In. for use with Hydraulic Booster
2000ChevroletK2500N/ABore size 1.25 In. for use with Hydraulic Booster
2000ChevroletTahoeN/AOld Body Style with Police Package
2000GMCC2500N/ABore size 1.25 In. for use with Hydraulic Booster
2000GMCK2500N/ABore size 1.25 In. for use with Hydraulic Booster
2000GMCYukonN/AOld Body Style with Police Package
1999ChevroletC1500N/ABore size 1.25 In. for use with Hydraulic Booster
1999ChevroletC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1999ChevroletC2500N/ABore size 1.25 In. for use with Hydraulic Booster
1999ChevroletC2500 SuburbanN/ABore size 1.25 In. for use with Hydraulic Booster
1999ChevroletK1500N/ACompatible with hydraulic booster.
1999ChevroletK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1999ChevroletK2500N/ABore size 1.25 In. for use with Hydraulic Booster
1999ChevroletK2500 SuburbanN/ABore size 1.25 In. for use with Hydraulic Booster
1999ChevroletTahoeGASN/ABore: 1.25 In.; w/Police Package
1999ChevroletTahoeDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1999GMCC1500N/ABore size 1.25 In. for use with Hydraulic Booster
1999GMCC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1999GMCC2500N/ABore size 1.25 In. for use with Hydraulic Booster
1999GMCC2500 SuburbanN/ABore size 1.25 In. for use with Hydraulic Booster
1999GMCK1500N/ACompatible with hydraulic booster.
1999GMCK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1999GMCK2500N/ABore size 1.25 In. for use with Hydraulic Booster
1999GMCK2500 SuburbanN/ABore size 1.25 In. for use with Hydraulic Booster
1999GMCYukonGASN/ABore: 1.25 In.; w/Police Package
1998ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998ChevroletC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998ChevroletC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1998ChevroletC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998ChevroletC2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1998ChevroletC2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998ChevroletK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998ChevroletK2500N/ABore size 1.25 In. for use with Hydraulic Booster
1998ChevroletK2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1998ChevroletK2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998ChevroletTahoeDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998GMCC1500N/ACompatible with hydraulic booster.
1998GMCC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998GMCC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1998GMCC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998GMCC2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1998GMCC2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998GMCK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998GMCK2500N/ABore size 1.25 In. for use with Hydraulic Booster
1998GMCK2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1998GMCK2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1998GMCYukonN/ACompatible with hydraulic booster.
1997ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997ChevroletC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997ChevroletC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1997ChevroletC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997ChevroletC2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1997ChevroletC2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997ChevroletK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997ChevroletK2500N/ABore size 1.25 In. for use with Hydraulic Booster
1997ChevroletK2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1997ChevroletK2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997ChevroletTahoeDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997DodgeRam 1500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997DodgeRam 2500RWDN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997DodgeRam 25004WDN/A7,500 lb. GVW with a 1.25 in. bore.
1997GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997GMCC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997GMCC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1997GMCC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997GMCC2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1997GMCC2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997GMCK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997GMCK2500N/ABore size 1.25 In. for use with Hydraulic Booster
1997GMCK2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1997GMCK2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1997GMCYukonDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1996ChevroletC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletC2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1996ChevroletC2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletK2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1996ChevroletK2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletK2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1996ChevroletK2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996ChevroletTahoeDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996DodgeRam 2500RWDN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996DodgeRam 25004WDN/A7,500 lb. GVW with a 1.25 in. bore.
1996GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996GMCC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996GMCC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1996GMCC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996GMCC2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1996GMCC2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996GMCK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996GMCK2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1996GMCK2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996GMCK2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1996GMCK2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1996GMCYukonDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1995ChevroletC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletC2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1995ChevroletC2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletK2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1995ChevroletK2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletK2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1995ChevroletK2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995ChevroletTahoeDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995DodgeRam 2500RWDN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995DodgeRam 25004WDN/A7,500 lb. GVW with a 1.25 in. bore.
1995GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995GMCC1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995GMCC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1995GMCC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995GMCC2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1995GMCC2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995GMCK1500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995GMCK2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1995GMCK2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995GMCK2500 SuburbanGASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1995GMCK2500 SuburbanDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1995GMCYukonDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1994ChevroletBlazerN/ABrake Master Cylinder fits with Hydraulic Booster and stamped 18013978.
1994ChevroletC1500N/ACompatible with hydraulic booster.
1994ChevroletC1500 SuburbanN/AFitment: Compatible with 13-inch brakes.
1994ChevroletC1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster
1994ChevroletC2500N/AFitment: Compatible with 13-inch brakes.
1994ChevroletC2500N/A11 In. Brakes; w/Hydraulic Booster
1994ChevroletC2500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster
1994ChevroletC2500 SuburbanN/AFitment: Compatible with 13-inch brakes.
1994ChevroletK1500N/ACompatible with hydraulic booster.
1994ChevroletK1500 SuburbanN/AFitment: Compatible with 13-inch brakes.
1994ChevroletK1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster
1994ChevroletK2500N/AFitment: Compatible with 13-inch brakes.
1994ChevroletK2500N/A11 In. Brakes; w/Hydraulic Booster
1994ChevroletK2500 SuburbanN/AFitment: Compatible with 13-inch brakes.
1994ChevroletK2500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster
1994GMCC1500N/ACompatible with hydraulic booster.
1994GMCC1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster
1994GMCC1500 SuburbanN/AFitment: Compatible with 13-inch brakes.
1994GMCC2500N/AFitment: Compatible with 13-inch brakes.
1994GMCC2500N/A11 In. Brakes; w/Hydraulic Booster
1994GMCC2500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster
1994GMCC2500 SuburbanN/AFitment: Compatible with 13-inch brakes.
1994GMCK1500N/ACompatible with hydraulic booster.
1994GMCK1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster
1994GMCK1500 SuburbanN/AFitment: Compatible with 13-inch brakes.
1994GMCK2500N/AFitment: Compatible with 13-inch brakes.
1994GMCK2500N/A11 In. Brakes; w/Hydraulic Booster
1994GMCK2500 SuburbanN/AFitment: Compatible with 13-inch brakes.
1994GMCK2500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster
1994GMCYukonN/ABrake Master Cylinder fits with Hydraulic Booster and stamped 18013978.

* Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.

This part directly replaces or is cross-referenced with the following part numbers:

10-268413-2684130.6603013056174-722180212754778453783-44030F131472M-86030M3011M900950MC131472MC390257

Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.

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