Dorman 904-856 Vacuum Pump

Overview of the Dorman 904-856 Electric Vacuum Pump

The Dorman 904-856 electric vacuum pump is designed to support emission control systems in a range of vehicles including Buick, Cadillac, Chevrolet, Chrysler, Dodge, Jeep, Ram, Saturn, and Volvo models. This vacuum pump provides reliable vacuum pressure essential for proper engine and brake system operation.

• Electric motor drive type for consistent vacuum generation
• Metal housing for durability and heat resistance
• Includes diaphragm with a diameter of 1.4 inches
• Blade-type terminals with a female rectangular connector
• Vacuum port diameter of 0.38 inches with barbed connector
• Two ports: one vacuum port and one outlet port
• Compatible with multiple vehicle makes and models from 200 to XC90

Technical Specifications and Features

The Dorman 904-856 vacuum pump features an electric motor drive system that ensures steady vacuum pressure without relying on engine vacuum. The metal housing enhances durability under high-temperature conditions. It has a vacuum port outside diameter of 0.38 inches and an outlet port outside diameter of 0.23 inches, both designed for secure hose connections. The diaphragm included measures 1.4 inches in diameter, contributing to efficient vacuum generation. The pump uses blade-type terminals with a female rectangular connector, facilitating straightforward electrical connections. This pump does not include a pulley, mounting hardware, gasket, or relief valve, so these components must be sourced separately if needed.

Compatible Vehicles and Applications

This vacuum pump is compatible with a wide range of vehicles, including Buick LaCrosse and Regal, Cadillac CTS and XTS, Chevrolet Impala and Malibu, Chrysler 200 and Town & Country, Dodge Challenger and Charger, Jeep Cherokee and Wrangler JK, Ram trucks, Saturn Outlook, and Volvo S40, S60, S80, V40, V50, V70, and XC90 models. The Dorman 904-856 is suitable for emission control and vacuum system applications where an electric vacuum pump is required.

Common Issues Addressed by the Dorman 904-856 Vacuum Pump

• Loss of vacuum pressure affecting brake booster performance
• Faulty or failing vacuum pump causing engine performance issues
• Emission control system malfunctions due to inadequate vacuum supply
• Vacuum leaks from worn or damaged pump diaphragms
• Electrical failures in vacuum pump motor or connectors

Installation Notes and Tips

When installing the Dorman 904-856 vacuum pump, ensure the electrical connections match the blade-type female rectangular connector for proper fit. Since mounting hardware and gaskets are not included, use OEM or compatible parts to secure the pump and seal connections. Verify hose diameters match the 0.38-inch vacuum port and 0.23-inch outlet port for leak-free operation. Follow vehicle-specific service manuals for torque specifications and wiring instructions to ensure safe and effective installation.

Quality Assurance and Warranty

Dorman parts are manufactured to meet or exceed OEM standards, with metal housings and durable diaphragms designed for long service life. The 904-856 vacuum pump undergoes quality control testing to ensure reliable performance in emission control and vacuum systems. Warranty coverage details should be confirmed at the time of purchase, typically including limited warranties against defects in materials and workmanship.