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Dorman M39670 Brake Master Cylinder
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.
| Brand | Dorman |
|---|---|
| Part Number | 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 |
This part fits 9 vehicles. Search below:
| Year | Make | Model | Position | Notes |
|---|---|---|---|---|
| 1991 | Audi | 100 Quattro | N/A | Exc. Heavy Duty Brakes; Bore: 15/16 In.; w/Girling Brake System |
| 1990 | Audi | 100 Quattro | N/A | Exc. Heavy Duty Brakes; Bore: 15/16 In.; w/Girling Brake System |
| 1989 | Audi | 100 | N/A | Fits 15/16" bore size drum brakes on multiple vehicle models. |
| 1988 | Audi | 5000 Quattro | N/A | Fits 15/16" bore size drum brakes on multiple vehicle models. |
| 1987 | Audi | 5000 Quattro | N/A | Fits 15/16" bore size drum brakes on multiple vehicle models. |
| 1986 | Audi | 5000 Quattro | N/A | Fits 15/16" bore size drum brakes on multiple vehicle models. |
| 1985 | Audi | Quattro | N/A | |
| 1984 | Audi | Quattro | N/A | |
| 1983 | Audi | Quattro | N/A | From VIN 85-D-900 358 |
* 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:
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.