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Dorman M390401 Brake Master Cylinder
Reliable Brake Master Cylinder for Buick, Chevrolet, Oldsmobile, and Pontiac
The Dorman M390401 Brake Master Cylinder is engineered to restore proper brake hydraulics in select Buick, Chevrolet, Oldsmobile, and Pontiac models. Designed with precision, this master cylinder ensures consistent brake fluid pressure for safe and responsive braking performance.
- Master cylinder bore diameter: 1 inch for accurate fluid displacement
- Constructed from durable aluminum material for corrosion resistance
- Includes reservoir and sensor for complete brake system integration
- Two outlets with M12 x 1.0 thread size for secure hydraulic connections
- Compatible with Buick Allure, Chevrolet Impala, Monte Carlo, Oldsmobile Intrigue, Pontiac Grand Prix, and other models
Detailed Product Features and Specifications
The Dorman M390401 master cylinder features a 1-inch bore diameter, which is critical for maintaining the correct hydraulic pressure within the brake system. Its aluminum construction offers strength and resistance to corrosion, extending the service life of the component. This unit comes complete with a reservoir and sensor, allowing for seamless integration with the vehicle’s brake fluid monitoring system. The two outlets, both sized M12 x 1.0 with a 1.0 thread pitch, provide reliable connections to the brake lines, ensuring leak-free operation.
Compatible Vehicles and Applications
This brake master cylinder is compatible with a range of GM vehicles, including Buick Allure and LaCrosse, Chevrolet Century, Impala, Montana, and Monte Carlo, Oldsmobile Intrigue and Silhouette, as well as Pontiac Grand Prix and Regal. The part number M390401 is specifically designed to meet the hydraulic requirements of these models, making it a suitable replacement for worn or damaged master cylinders in these vehicles.
Common Issues Addressed by This Master Cylinder
- Brake pedal sinking or sponginess due to internal leaks
- Brake fluid leaks around the master cylinder or reservoir
- Inconsistent brake pressure causing uneven braking
- Warning lights triggered by faulty brake fluid sensors
- Reduced braking performance from worn or damaged master cylinder components
Installation Notes and Tips
Installation of the Dorman M390401 master cylinder requires proper brake system bleeding to remove air and ensure optimal hydraulic function. Note that mounting hardware is not included, so retain original fasteners or acquire appropriate replacements. Verify thread sizes (M12 x 1.0) for brake line fittings to ensure compatibility. It is recommended to inspect related brake components during installation for overall system integrity.
Quality Assurance and Warranty Information
Dorman manufactures this brake master cylinder to meet or exceed OEM specifications, using quality aluminum materials and precise machining. The included sensor and reservoir are tested for reliable operation within the brake system. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship to provide confidence in product durability.
| Brand | Dorman |
|---|---|
| Part Number | M390401 |
| Master Cylinder Bore Diameter | 1 |
| Master Cylinder Material | Aluminum |
| Mounting Hardware Included | No |
| Number of Outlets | 2 |
| Package Contents | Master Cylinder |
| Rearward Outlet Size | M12 X 1.0 |
| Reservoir Included | Yes |
| Secondary Outlet Thread Diameter | M12 X 1.0 |
| Sensor Included | Yes |
| Thread Pitch | 1.0 |
This part fits 63 vehicles. Search below:
| Year | Make | Model | Submodel | Liters | Cylinders | Position | Notes |
|---|---|---|---|---|---|---|---|
| 2009 | Buick | Allure | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2009 | Buick | LaCrosse | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2008 | Buick | Allure | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | |||
| 2008 | Buick | LaCrosse | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | |||
| 2008 | Pontiac | Grand Prix | Base | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | ||
| 2007 | Buick | Allure | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | |||
| 2007 | Buick | LaCrosse | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | |||
| 2007 | Pontiac | Grand Prix | Base | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | ||
| 2007 | Pontiac | Grand Prix | GT | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | ||
| 2006 | Buick | Allure | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | |||
| 2006 | Buick | LaCrosse | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | |||
| 2006 | Pontiac | Grand Prix | Base | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | ||
| 2006 | Pontiac | Grand Prix | GT | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | ||
| 2005 | Buick | Allure | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | |||
| 2005 | Buick | Century | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2005 | Buick | LaCrosse | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | |||
| 2005 | Chevrolet | Impala | 3.8L | V6 | N/A | Bore size: 1 In. for Light Duty Brakes | |
| 2005 | Chevrolet | Monte Carlo | 3.8L | V6 | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |
| 2005 | Pontiac | Grand Prix | Base | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | ||
| 2005 | Pontiac | Grand Prix | GT | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | ||
| 2005 | Pontiac | Grand Prix | GTP | N/A | Fitment Note: Bore size of 1 inch, compatible with vehicles equipped with RPO Code JL9 for power brakes, 4 wheel disc brakes, and ABS. | ||
| 2005 | Pontiac | Montana | Base | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | ||
| 2004 | Buick | Regal | N/A | Rear Drum Brakes with a 1" Bore. | |||
| 2004 | Chevrolet | Impala | 3.8L | V6 | N/A | Bore size: 1 In. for Light Duty Brakes | |
| 2004 | Chevrolet | Monte Carlo | 3.8L | V6 | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |
| 2004 | Oldsmobile | Silhouette | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2004 | Pontiac | Grand Prix | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2004 | Pontiac | Montana | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2003 | Buick | Century | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2003 | Buick | Regal | N/A | Rear Drum Brakes with a 1" Bore. | |||
| 2003 | Chevrolet | Impala | 3.8L | V6 | N/A | Bore size: 1 In. for Light Duty Brakes | |
| 2003 | Chevrolet | Monte Carlo | 3.8L | V6 | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |
| 2003 | Oldsmobile | Silhouette | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2003 | Pontiac | Grand Prix | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2003 | Pontiac | Montana | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2002 | Buick | Century | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2002 | Buick | Regal | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2002 | Chevrolet | Impala | N/A | Bore size: 1 In. for Light Duty Brakes | |||
| 2002 | Chevrolet | Monte Carlo | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2002 | Oldsmobile | Intrigue | N/A | For vehicles without Active Brake Control, 1-inch bore size. | |||
| 2002 | Oldsmobile | Silhouette | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2002 | Pontiac | Grand Prix | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2002 | Pontiac | Montana | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2001 | Buick | Century | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2001 | Buick | Regal | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2001 | Chevrolet | Impala | N/A | Bore size: 1 In. for Light Duty Brakes | |||
| 2001 | Chevrolet | Monte Carlo | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2001 | Oldsmobile | Intrigue | N/A | For vehicles without Active Brake Control, 1-inch bore size. | |||
| 2001 | Oldsmobile | Silhouette | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2001 | Pontiac | Grand Prix | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2001 | Pontiac | Montana | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2000 | Buick | Century | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2000 | Buick | Regal | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2000 | Chevrolet | Impala | N/A | Bore size: 1 In. for Light Duty Brakes | |||
| 2000 | Chevrolet | Monte Carlo | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2000 | Oldsmobile | Intrigue | N/A | For vehicles without Active Brake Control, 1-inch bore size. | |||
| 2000 | Oldsmobile | Silhouette | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2000 | Pontiac | Grand Prix | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 2000 | Pontiac | Montana | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 1999 | Buick | Century | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 1999 | Buick | Regal | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 1999 | Pontiac | Grand Prix | N/A | Compatible with 1-inch bore drum brake wheel cylinders. | |||
| 1998 | Pontiac | Grand Prix | N/A | Compatible with 1-inch bore drum brake wheel cylinders. |
* 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.