Dorman M39670 Brake Master Cylinder

Brand Dorman M39670
Mounting Hardware Included No
Master Cylinder Bore Diameter 0.938
Master Cylinder Material Aluminum
Reservoir Included No
Secondary Outlet Thread Diameter 10
Sensor Included No
Number of Outlets 4
Package Contents Master cylinder
Rearward Outlet Size M10 x 1.0
Thread Pitch 1.0
Fits Audi · 14 vehicles

OE-style replacement. Precision-engineered to match original design, function, and performance.

Aluminum construction. Made from new materials for a durable brake master cylinder.

Four outlets. Built for brake hydraulic systems with multiple outlet connections.

Cross-references Cardone New 13-2042, Cardone Reman 11-2042 and Centric Parts 130.33102 for the same application. See all 14.

$138.80Free shipping
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Order total $138.80
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Brake Master Cylinder for Audi Quattro Applications

This Dorman brake master cylinder is built for specific Audi brake hydraulics applications, including Audi 100, 100 Quattro, 5000 Quattro, and Quattro models. Part number M39670 is a direct-fit replacement made with new aluminum construction for consistent brake system performance.

  • Brake master cylinder for select Audi vehicles
  • Aluminum master cylinder body
  • 0.938 in. bore diameter
  • 4 outlet design
  • Rearward outlet size: M10 x 1.0
  • Secondary outlet thread diameter: 10 mm
  • No reservoir included
  • No sensor included

OE-Style Replacement Design

Dorman M39670 is precision-engineered to match the original master cylinder’s design, function, and performance on the listed vehicle years, makes, and models. It uses new, high-quality materials to support safe, durable brake system service on Audi 100 Quattro, Audi 5000 Quattro, and Audi Quattro applications. This part cross-references Cardone New 13-2042 and Cardone Reman 11-2042 for the same application.

Vehicle Fitment

  • Fits 1990-1991 Audi 100 Quattro, N/A; Exc. Heavy Duty Brakes; Bore: 15/16 In.; w/Girling Brake System
  • Fits 1989 Audi 100, N/A; Fits 15/16" bore size drum brakes on multiple vehicle models.
  • Fits 1986-1988 Audi 5000 Quattro, N/A; Fits 15/16" bore size drum brakes on multiple vehicle models.
  • Fits 1984-1985 Audi Quattro, N/A
  • Fits 1983 Audi Quattro, N/A; From VIN 85-D-900 358

What This Part Helps Address

  • Soft or inconsistent brake pedal feel caused by master cylinder wear
  • Brake fluid leakage from a failing master cylinder assembly
  • Loss of hydraulic pressure in the brake system
  • Uneven brake response during normal stopping
  • Service replacement needs on older Audi brake hydraulics systems

Installation Notes and Tips

Verify bore diameter, outlet thread size, and brake system configuration before installation. This master cylinder does not include a reservoir, sensor, or mounting hardware, so reuse or source the required related components separately. Bench bleeding is recommended before installation to help remove air from the hydraulic circuit and support proper pedal feel after service.

Quality Assurance

Dorman manufactures this brake master cylinder as a new replacement part using durable materials and application-specific engineering for the listed Audi models. Part number M39670 is built to match OE-style fit and function for brake system repair.

This part fits 14 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelBody TypeNotes
1991Audi100 QuattroExc. Heavy Duty Brakes; Bore: 15/16 In.; w/Girling Brake System
1990Audi100 QuattroExc. Heavy Duty Brakes; Bore: 15/16 In.; w/Girling Brake System
1989Audi100Fits 15/16" bore size drum brakes on multiple vehicle models.
1988Audi5000SedanFits 15/16" bore size drum brakes on multiple vehicle models.
1988Audi5000 QuattroFits 15/16" bore size drum brakes on multiple vehicle models.
1987Audi5000SedanFits 15/16" bore size drum brakes on multiple vehicle models.
1987Audi5000 QuattroFits 15/16" bore size drum brakes on multiple vehicle models.
1986Audi5000SedanFits 15/16" bore size drum brakes on multiple vehicle models.
1986Audi5000 QuattroFits 15/16" bore size drum brakes on multiple vehicle models.
1985Audi5000SedanFits 15/16" bore size drum brakes on multiple vehicle models.
1985AudiQuattro
1984Audi5000SedanFits 15/16" bore size drum brakes on multiple vehicle models.
1984AudiQuattro
1983AudiQuattroFrom VIN 85-D-900 358
Directly replaces or cross-references 14 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Cardone New — 13-2042Cardone Reman — 11-2042Centric Parts — 130.33102Gates — 1204218M377072-8295783-96102443611021F107743M-02102M52042M900583MC107743MC390097