Dorman 904-821 Vacuum Pump

Overview of Dorman 904-821 Vacuum Pump for BMW and Rolls-Royce

The Dorman 904-821 vacuum pump is designed specifically for select BMW and Rolls-Royce models, including the 545i, 550i, 645Ci, 650i, 745i, 745Li, 750i, 750Li, 760i, 760Li, Phantom, and X5. This vacuum pump supports the emission control system by maintaining proper vacuum pressure essential for various engine functions.

• Aluminum housing for durability and lightweight performance
• Gear-driven vacuum pump drive system for reliable operation
• Barbed vacuum pump connector for secure hose attachment
• Vacuum pump inlet size: 1/2 inch
• Vacuum pump outlet size: 1/8 inch
• No pulley or gasket/seal included
• Package includes one vacuum pump unit

Technical Details and Construction

The Dorman 904-821 vacuum pump features a robust aluminum housing that ensures resistance to corrosion and heat, making it suitable for the demanding environment of BMW and Rolls-Royce engines. Its gear-driven mechanism provides consistent vacuum generation, which is critical for emission control and other vacuum-dependent systems. The barbed connector design allows for a secure and leak-free connection to vacuum lines, supporting efficient system performance. This pump does not include a pulley or gasket, so those components must be sourced separately if needed.

Compatible Vehicles and Applications

This vacuum pump is compatible with a range of BMW models such as the 545i, 550i, 645Ci, 650i, 745i, 745Li, 750i, 750Li, 760i, 760Li, and the X5. It is also designed for use in Rolls-Royce Phantom vehicles. The Dorman 904-821 is intended for emission control systems that rely on vacuum pressure to operate components like brake boosters and EGR valves.

• Restores vacuum pressure for brake booster assistance
• Supports proper function of emission control valves
• Helps resolve engine performance issues related to vacuum leaks
• Addresses rough idling caused by vacuum system failure
• Prevents check engine light triggers related to vacuum faults

Installation Notes and Tips

When installing the Dorman 904-821 vacuum pump, ensure the mating surfaces are clean and free of debris. Since the pump does not include a gasket or seal, use a compatible gasket to prevent leaks. Verify that the gear drive system meshes correctly with the engine components to avoid premature wear. Properly secure the barbed vacuum connector hose to prevent disconnection during operation. It is recommended to inspect related vacuum lines and replace any damaged hoses during installation.

Quality Assurance and Warranty

Dorman manufactures the 904-821 vacuum pump to meet or exceed OEM specifications for fit, form, and function. The aluminum housing and gear-driven design contribute to long service life under normal operating conditions. While specific warranty details are not provided here, Dorman typically offers limited warranties on their emission control components. Consult product documentation or the supplier for exact warranty terms.