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Dorman M390591 Brake Master Cylinder 7/8 In. Bore OE Replacement

(1996, 1999-2000 Honda Civic; 1974 Chevrolet El Camino; 1973-1974 Chevrolet P30 Van Base; 1973 Chevrolet P10 Van Base + 4 more models)

Part of: Dorman Brake Master Cylinder Replacement

Other options in this family: Dorman M39298 Dorman M19012 Dorman M390139 Dorman M630735 Dorman M390200

Manufacturer

Picture for manufacturer Dorman

Part Number

M390591
6 reviews
Sale Price

$114.46

In Stock (5)

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Usually delivered within 2 days

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Product Details

The Dorman M390591 is a 100% new OE-replacement brake master cylinder engineered to restore proper hydraulic braking pressure to compatible vehicles. With a 7/8-inch bore diameter, this unit delivers the precise hydraulic output needed for confident, reliable stopping power.

Key Features:

  • Precise OE Replacement — Cylinder housing is constructed to match the casting material of the original part for accurate fit and similar performance
  • Durable EPDM Rubber Components — All internal seals and rubber parts are made from high-quality EPDM compound, providing resistance to glycol-based brake fluid
  • 100% New Construction — Made entirely from new materials, not remanufactured, ensuring the highest standard of quality and safety
  • SAE-Compliant Manufacturing — Built to meet rigorous SAE International standards for hydraulic brake system components
  • 7/8 In. Bore Diameter — Engineered to deliver correct hydraulic pressure for effective brake pedal feel and stopping performance

The Dorman M390591 brake master cylinder is a direct-fit replacement designed to address issues such as a soft or spongy brake pedal, internal fluid leaks, or worn seals in the original unit. As with any brake master cylinder replacement, a full brake system bleed is recommended after installation to purge air and restore optimal hydraulic function.

Products specifications

Fits

1996, 1999-2000 Honda Civic; 1974 Chevrolet El Camino; 1973-1974 Chevrolet P30 Van Base; 1973 Chevrolet P10 Van Base; 1973 Chevrolet P20 Van Base; 1974 GMC Sprint; 1973-1974 GMC P35/P3500 Van Base; 1974 GMC P35/P3500 Van Motor Home

Feature - Benefit 1

Cylinder housing is constructed from high-quality cast iron or aluminum for long-lasting durability

Feature - Benefit 2

All rubber components are of high-quality EPDM compound for resistance to glycol-based brake fluid

Feature - Benefit 3

Direct replacement for a proper fit

Feature - Benefit 4

Manufactured to strict engineering quality standards, each Brake Master Cylinder meets S.A.E. specifications

Master Cylinder Material

Aluminum

Sensor Included

Yes

Number of Outlets

2

Master Cylinder Bore Diameter

0.875

Mounting Hardware Included

No

Secondary Outlet Thread Diameter

10

Reservoir Included

Yes

Package Contents

Master Cylinder

Thread Pitch

1.0

Rearward Outlet Size

M10 X 1.0

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