OE Quality
60-Day Returns

Dorman 42073 Brake Master Cylinder Reservoir Cap Gasket
Reliable Brake Master Cylinder Reservoir Cap Gasket for Chevrolet and GMC
The Dorman 42073 brake master cylinder reservoir cap gasket is designed to provide a secure seal for your vehicle's brake system. Made from durable rubber, this gasket ensures proper sealing and prevents fluid leaks in Chevrolet and GMC models including Astro, G10, G20, G30, P20, P30, P2500, P3500, and Safari.
- Constructed from high-quality rubber material for durability and flexibility
- Includes one brake master cylinder reservoir cap gasket per package
- Compatible with multiple Chevrolet and GMC van and truck models
- Part number 42073 ensures precise fit and reliable performance
Durable Rubber Material for Effective Sealing
This brake master cylinder reservoir cap gasket is crafted from rubber, a material known for its excellent sealing properties and resistance to brake fluid. The flexibility of rubber allows the gasket to maintain a tight seal under varying temperatures and pressure conditions, reducing the risk of leaks and contamination in the brake fluid reservoir. The Dorman 42073 gasket is engineered to meet OEM specifications, providing a dependable replacement part for your vehicleβs brake system.
Compatible Chevrolet and GMC Models
This gasket is specifically designed for use with Chevrolet and GMC vehicles, including the Astro, G10, G20, G30, P20, P30, P2500, P3500, and Safari models. Using the correct gasket ensures proper fitment and optimal brake system performance. The Dorman 42073 part number corresponds directly to these applications, making it easier to identify the right component for your vehicle.
Common Applications and Problem Solving
- Prevents brake fluid leaks from the master cylinder reservoir cap
- Eliminates contamination of brake fluid by sealing out dirt and moisture
- Maintains proper brake system pressure and function
- Replaces worn or damaged gaskets that cause fluid seepage
- Helps avoid brake system failure due to fluid loss
Installation Notes and Tips
When installing the Dorman 42073 brake master cylinder reservoir cap gasket, ensure the reservoir cap and sealing surface are clean and free of debris. Carefully remove the old gasket and inspect the reservoir for any damage. Position the new rubber gasket evenly to avoid pinching or misalignment, which could cause leaks. Tighten the reservoir cap securely but avoid over-tightening to prevent damage to the gasket or cap.
Quality Assurance and Warranty
Dorman parts are manufactured to meet or exceed OEM standards, providing reliable performance and durability. The 42073 brake master cylinder reservoir cap gasket undergoes quality checks to ensure proper material composition and fitment. While specific warranty details may vary, Dorman typically offers limited warranties covering defects in material and workmanship for their replacement parts.
| Brand | Dorman |
| Part Number | 42073 |
| Material | Rubber |
| Package Contents | 1 Brake Master Cylinder Gasket |
This part fits 112 vehicles. Search below:
| Year | Make | Model | Fuel Type | Position | Notes |
|---|---|---|---|---|---|
| 1996 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1996 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1995 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1995 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1995 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1995 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1994 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1994 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1994 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1994 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1994 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1994 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1994 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1994 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1993 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1993 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1993 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1993 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1993 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1993 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1993 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1993 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1992 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1992 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1992 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1992 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1992 | Chevrolet | P30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1992 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1992 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1992 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1992 | GMC | P3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1992 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1991 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1991 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1991 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1991 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1991 | Chevrolet | P30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1991 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1991 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1991 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1991 | GMC | P3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1991 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1990 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1990 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1990 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1990 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1990 | Chevrolet | P30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1990 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1990 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1990 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1990 | GMC | P3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1990 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1989 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1989 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1989 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1989 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1989 | Chevrolet | P20 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1989 | Chevrolet | P30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1989 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1989 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1989 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1989 | GMC | P2500 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1989 | GMC | P3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1989 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1988 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1988 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1988 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1988 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1988 | Chevrolet | P20 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1988 | Chevrolet | P30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1988 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1988 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1988 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1988 | GMC | P2500 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1988 | GMC | P3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1988 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1987 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1987 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1987 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1987 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1987 | Chevrolet | P20 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1987 | Chevrolet | P30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1987 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1987 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1987 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1987 | GMC | P2500 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1987 | GMC | P3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1987 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1986 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1986 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1986 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1986 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1986 | Chevrolet | P20 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1986 | Chevrolet | P30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1986 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1986 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1986 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1986 | GMC | P2500 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1986 | GMC | P3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1986 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1985 | Chevrolet | Astro | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1985 | Chevrolet | G10 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1985 | Chevrolet | G20 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1985 | Chevrolet | G30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1985 | Chevrolet | P20 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1985 | Chevrolet | P30 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1985 | GMC | G1500 | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket | |
| 1985 | GMC | G2500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1985 | GMC | G3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1985 | GMC | P2500 | GAS | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
| 1985 | GMC | P3500 | N/A | Front Reservoir; w/Vacuum Power Brakes | |
| 1985 | GMC | Safari | N/A | Front Reservoir - Brake Master Cylinder Cap Gasket |
* 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.