Dorman M39646 Brake Master Cylinder

Name: Dorman M39646 Brake Master Cylinder
Brand: Dorman
SKU: BKKX-M39646
Price: 61.50 USD
Availability: InStock

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85 vehicles fit this part

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OE Direct Replacement — Bolt-on fit, no modifications needed

Fitment: Chevrolet, Dodge, and GMC, Blazer, C1500 Suburban, C2500, C2500 Suburban, K1500 Suburban, K2500, K2500 Suburban, Ram 1500, Yukon, C1500, and K1500

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Reliable Brake Master Cylinder for Chevrolet, Dodge, and GMC Vehicles

The Dorman M39646 Brake Master Cylinder is engineered to restore proper brake hydraulics in select Chevrolet, Dodge, and GMC trucks and SUVs. Designed with precision, this master cylinder ensures consistent brake fluid pressure for safe and effective braking performance.

Includes reservoir for brake fluid storage
Constructed from durable aluminum material
Dual outlet design with rearward outlet size 1/2-20 and secondary outlet thread diameter 9/16-18
Master cylinder bore diameters of 1.125 and 1.578 inches for optimal hydraulic function
Compatible with Chevrolet Blazer, C1500, C1500 Suburban, C2500, C2500 Suburban, K1500, K1500 Suburban, K2500, K2500 Suburban, Dodge Ram 1500, and GMC Yukon

Product Features and Specifications

The Dorman M39646 master cylinder is crafted from aluminum, providing corrosion resistance and long-lasting durability. It features two outlets to accommodate brake line connections, with precise thread sizes of 1/2-20 for the rearward outlet and 9/16-18 for the secondary outlet. The inclusion of a reservoir allows for proper brake fluid containment and circulation. Bore diameters of 1.125 and 1.578 inches ensure compatibility with the hydraulic systems of various Chevrolet, Dodge, and GMC models, including the Blazer, Ram 1500, and Yukon.

Common Applications and Problem Resolution

Restores brake fluid pressure in vehicles experiencing spongy or unresponsive brakes
Replaces master cylinders with leaks or internal seal failures
Addresses brake pedal sinking or inconsistent brake pedal feel
Resolves issues related to brake fluid contamination or reservoir damage
Improves overall brake system reliability in Chevrolet, Dodge, and GMC trucks and SUVs

Installation Notes and Tips

Installation of the Dorman M39646 master cylinder requires proper brake system bleeding to remove air and ensure optimal hydraulic performance. Mounting hardware is not included, so existing hardware should be inspected and replaced if necessary. It is recommended to verify bore diameter compatibility with the vehicle’s brake system before installation. Professional installation is advised for accurate fitting and safety compliance.

Quality Assurance and Warranty Information

Dorman manufactures this brake master cylinder to meet or exceed OEM standards for fit, form, and function. The aluminum construction provides resistance to corrosion and wear, contributing to long service life. While specific warranty details are not provided, Dorman products typically come with a limited warranty covering defects in material and workmanship. Consult product documentation for exact warranty terms.

Brand	Dorman
Part Number	M39646
Master Cylinder Bore Diameter	1.125
Master Cylinder Bore Diameter	1.578
Master Cylinder Material	Aluminum
Mounting Hardware Included	No
Number of Outlets	2
Package Contents	Master Cylinder
Rearward Outlet Size	1/2-20
Reservoir Included	Yes
Secondary Outlet Thread Diameter	9/16-18
Sensor Included	No

This part fits 85 vehicles. Search below:

Year	Make	Model	Fuel Type	Position	Notes
1994	Chevrolet	Blazer	GAS	N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1994	Chevrolet	C1500 Suburban		N/A	Compatible with drum brake systems with a 1.125" bore size.
1994	Chevrolet	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1994	Chevrolet	C2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1994	Chevrolet	K1500 Suburban		N/A	Compatible with drum brake systems with a 1.125" bore size.
1994	Chevrolet	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1994	Chevrolet	K2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1994	Dodge	Ram 1500		N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1994	GMC	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1994	GMC	C2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1994	GMC	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1994	GMC	K2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1994	GMC	Yukon	GAS	N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1993	Chevrolet	Blazer		N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1993	Chevrolet	C1500	GAS	N/A	Compatible with drum brake systems with a 1.125" bore size.
1993	Chevrolet	C1500 Suburban		N/A	Compatible with drum brake systems with a 1.125" bore size.
1993	Chevrolet	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1993	Chevrolet	C2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1993	Chevrolet	K1500	GAS	N/A	Compatible with drum brake systems with a 1.125" bore size.
1993	Chevrolet	K1500 Suburban		N/A	Compatible with drum brake systems with a 1.125" bore size.
1993	Chevrolet	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1993	Chevrolet	K2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1993	GMC	C1500	GAS	N/A	Compatible with drum brake systems with a 1.125" bore size.
1993	GMC	C1500 Suburban		N/A	Compatible with vehicles equipped with 11-inch brakes, vacuum booster, and stamped part number 18013977.
1993	GMC	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1993	GMC	C2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1993	GMC	K1500	GAS	N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1993	GMC	K1500 Suburban		N/A	Compatible with vehicles equipped with 11-inch brakes, vacuum booster, and stamped part number 18013977.
1993	GMC	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1993	GMC	K2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1993	GMC	Yukon		N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1992	Chevrolet	Blazer		N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1992	Chevrolet	C1500	GAS	N/A	Compatible with drum brake systems with a 1.125" bore size.
1992	Chevrolet	C1500 Suburban		N/A	Compatible with drum brake systems with a 1.125" bore size.
1992	Chevrolet	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1992	Chevrolet	C2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1992	Chevrolet	K1500	GAS	N/A	Compatible with drum brake systems with a 1.125" bore size.
1992	Chevrolet	K1500 Suburban		N/A	Compatible with drum brake systems with a 1.125" bore size.
1992	Chevrolet	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1992	Chevrolet	K2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1992	GMC	C1500	GAS	N/A	Compatible with drum brake systems with a 1.125" bore size.
1992	GMC	C1500 Suburban		N/A	Compatible with vehicles equipped with 11-inch brakes, vacuum booster, and stamped part number 18013977.
1992	GMC	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1992	GMC	C2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1992	GMC	K1500	GAS	N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1992	GMC	K1500 Suburban		N/A	Compatible with vehicles equipped with 11-inch brakes, vacuum booster, and stamped part number 18013977.
1992	GMC	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1992	GMC	K2500 Suburban		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1992	GMC	Yukon		N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1991	Chevrolet	C1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1991	Chevrolet	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1991	Chevrolet	K1500	GAS	N/A	Fitment note: Compatible with vehicles equipped with Heavy Duty Suspension, featuring a 1.125-inch bore.
1991	Chevrolet	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1991	GMC	C1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1991	GMC	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1991	GMC	K1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1991	GMC	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1990	Chevrolet	C1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1990	Chevrolet	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1990	Chevrolet	K1500	GAS	N/A	Fitment note: Compatible with vehicles equipped with Heavy Duty Suspension, featuring a 1.125-inch bore.
1990	Chevrolet	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1990	GMC	C1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1990	GMC	C2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1990	GMC	K1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1990	GMC	K2500		N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1989	Chevrolet	C1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1989	Chevrolet	C2500	GAS	N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1989	Chevrolet	C2500	DIESEL	N/A	Compatible with drum brake systems with a 1.125" bore size.
1989	Chevrolet	K1500	GAS	N/A	Fitment note: Compatible with vehicles equipped with Heavy Duty Suspension, featuring a 1.125-inch bore.
1989	Chevrolet	K2500	GAS	N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1989	GMC	C1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1989	GMC	C2500	GAS	N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1989	GMC	C2500	DIESEL	N/A	Compatible with drum brake systems with a 1.125" bore size.
1989	GMC	K1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1989	GMC	K2500	GAS	N/A	7,200 Lb. GVW, Bore sizes: 1.125 In. and 1.5781 In.
1988	Chevrolet	C1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1988	Chevrolet	C2500	GAS	N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1988	Chevrolet	C2500	DIESEL	N/A	Compatible with drum brake systems with a 1.125" bore size.
1988	Chevrolet	K1500	GAS	N/A	Fitment note: Compatible with vehicles equipped with Heavy Duty Suspension, featuring a 1.125-inch bore.
1988	Chevrolet	K2500	GAS	N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1988	GMC	C1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1988	GMC	C2500	GAS	N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".
1988	GMC	C2500	DIESEL	N/A	Compatible with drum brake systems with a 1.125" bore size.
1988	GMC	K1500	GAS	N/A	Fits vehicles with Heavy Duty Suspension and bore sizes of 1.125 In. and 1.5781 In.
1988	GMC	K2500	GAS	N/A	Compatible with brake master cylinders with bore sizes of 1.125" and 1.5781".

* 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:

10-23521221913-2352130.66021174-6681801397725396464746392783-44021F116881M-86021M900567MC116881NM2219

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