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Dorman M39649 Brake Master CylinderOE Quality 60-Day Returns
Part #: M39649

Dorman M39649 Brake Master Cylinder

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117 vehicles fit this part
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Fitment: Chevrolet, Dodge, and GMC, Blazer, C2500, C2500 Suburban, K2500, K2500 Suburban, K3500, Ram 2500, Yukon, C1500, C1500 Suburban, C3500, K1500, and K1500 Suburban
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Reliable Brake Master Cylinder for Chevrolet, Dodge, and GMC Vehicles

The Dorman M39649 brake master cylinder is engineered to restore proper brake hydraulics in select Chevrolet, Dodge, and GMC trucks and SUVs. Designed with a cast iron body and a 1.25-inch bore diameter, this master cylinder includes a reservoir and features dual outlets to ensure consistent brake fluid delivery.

  • Master cylinder bore diameter: 1.25 inches for precise hydraulic pressure
  • Durable cast iron construction for long-lasting performance
  • 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, C3500, K1500, K1500 Suburban, K2500, K2500 Suburban, K3500, Ram 2500, and GMC Yukon

Product Details and Specifications

The Dorman M39649 brake master cylinder is constructed from cast iron, providing the strength needed to withstand the demands of brake hydraulics in heavy-duty trucks and SUVs. Its 1.25-inch bore diameter is designed to deliver the correct hydraulic pressure for reliable braking performance. This master cylinder comes with an integrated reservoir, eliminating the need for a separate fluid container. It features two outlets: a rearward outlet sized at 1/2-20 and a secondary outlet with a 9/16-18 thread diameter, allowing for proper brake line connections. Note that mounting hardware is not included with this part.

Compatible Vehicles and Applications

  • Chevrolet Blazer and Suburban models including C1500, C2500, and C3500 series
  • Dodge Ram 2500 trucks
  • GMC K1500, K2500, K3500, and Yukon models

Common Issues Addressed by This Master Cylinder

  • Brake pedal sinking or sponginess due to internal leaks
  • Brake fluid leaks from a worn or damaged master cylinder
  • Reduced braking efficiency or uneven brake pressure
  • Brake warning light activation related to master cylinder failure
  • Contaminated or deteriorated brake fluid reservoir

Installation Notes and Tips

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

Quality Assurance and Warranty

Dorman manufactures the M39649 brake master cylinder to meet or exceed OEM standards for fit and function. The cast iron construction and integrated reservoir contribute to reliable brake system performance. While mounting hardware is not included, the part is designed for direct replacement on compatible Chevrolet, Dodge, and GMC models. Warranty coverage details should be confirmed at the point of purchase or through Dorman's official channels.

BrandDorman
Part NumberM39649
Master Cylinder Bore Diameter1.25
Master Cylinder MaterialCast Iron
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 117 vehicles. Search below:

YearMakeModelDrive TypeFuel TypePositionNotes
1994ChevroletBlazerDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1994ChevroletC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1994ChevroletC2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1994ChevroletK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1994ChevroletK2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1994ChevroletK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1994DodgeRam 2500RWDN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1994GMCC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1994GMCC2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1994GMCK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1994GMCK2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1994GMCK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1994GMCYukonDIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1993ChevroletBlazerN/ABrake Master Cylinder fits with Hydraulic Booster and stamped 18013978.
1993ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1993ChevroletC1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster; Stamped-18013978
1993ChevroletC1500 SuburbanN/A13 In. Brakes, Stamped-18013978
1993ChevroletC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1993ChevroletC2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1993ChevroletC3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1993ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1993ChevroletK1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster; Stamped-18013978
1993ChevroletK1500 SuburbanN/A13 In. Brakes, Stamped-18013978
1993ChevroletK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1993ChevroletK2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1993ChevroletK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1993GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1993GMCC1500 SuburbanN/A13 In. Brakes, Stamped-18013978
1993GMCC1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster; Stamped-18013978
1993GMCC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1993GMCC2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1993GMCC3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1993GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1993GMCK1500 SuburbanN/A13 In. Brakes, Stamped-18013978
1993GMCK1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster; Stamped-18013978
1993GMCK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1993GMCK2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1993GMCK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1993GMCYukonN/ABrake Master Cylinder fits with Hydraulic Booster and stamped 18013978.
1992ChevroletBlazerN/ABrake Master Cylinder fits with Hydraulic Booster and stamped 18013978.
1992ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1992ChevroletC1500 SuburbanN/A13 In. Brakes, Stamped-18013978
1992ChevroletC1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster; Stamped-18013978
1992ChevroletC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1992ChevroletC2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1992ChevroletC3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1992ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1992ChevroletK1500 SuburbanN/A13 In. Brakes, Stamped-18013978
1992ChevroletK1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster; Stamped-18013978
1992ChevroletK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1992ChevroletK2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1992ChevroletK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1992GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1992GMCC1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster; Stamped-18013978
1992GMCC1500 SuburbanN/A13 In. Brakes, Stamped-18013978
1992GMCC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1992GMCC2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1992GMCC3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1992GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1992GMCK1500 SuburbanN/A11 In. Brakes; w/Hydraulic Booster; Stamped-18013978
1992GMCK1500 SuburbanN/A13 In. Brakes, Stamped-18013978
1992GMCK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1992GMCK2500 SuburbanN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1992GMCK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1992GMCYukonN/ABrake Master Cylinder fits with Hydraulic Booster and stamped 18013978.
1991ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1991ChevroletC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1991ChevroletC3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1991ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1991ChevroletK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1991ChevroletK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1991GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1991GMCC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1991GMCC3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1991GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1991GMCK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1991GMCK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1990ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1990ChevroletC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1990ChevroletC3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1990ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1990ChevroletK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1990ChevroletK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1990GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1990GMCC2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1990GMCC3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1990GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1990GMCK2500N/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1990GMCK3500N/AFor vehicles with Single Rear Wheel (SRW), the brake master cylinder bore size is 1.25 inches.
1989ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989ChevroletC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1989ChevroletC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989ChevroletC3500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989ChevroletK2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1989ChevroletK2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989ChevroletK3500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989GMCC2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1989GMCC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989GMCC3500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989GMCK2500GASN/ACompatible with Brake Master Cylinders featuring 8,600 Lb. GVW and 1.25 In. bore.
1989GMCK2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1989GMCK3500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988ChevroletC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988ChevroletC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988ChevroletC3500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988ChevroletK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988ChevroletK2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988ChevroletK3500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988GMCC1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988GMCC2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988GMCC3500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988GMCK1500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988GMCK2500DIESELN/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.
1988GMCK3500N/AVerify vehicle compatibility before purchasing 1.25" bore size drum brake wheel cylinder.

* 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:

10-23531222013-2353130.66022174-6691801397825396494746398783-44022F116627M-86022M900570MC116627NM2220

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

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