Dorman 994-157 Vacuum Switching Valve

Overview of Dorman Vacuum Switching Valve 994-157

The Dorman Vacuum Switching Valve 994-157 is a precision-engineered metal component designed for emission control systems. It is compatible with various Lexus and Toyota models, including the Avalon, Camry, ES350, Highlander, RX350, RX450h, Sienna, Solara, and Venza, ensuring reliable vacuum management in your vehicle's emission system.

• Constructed from durable metal for long-lasting performance
• Measures 75 mm in length with three ports for efficient vacuum control
• Port diameters: Port 1 at 0.25 inches, Ports 2 and 3 at 4 mm outside diameter
• Includes one mounting hole with a 6.6 mm diameter for secure installation
• Features two electrical terminals and threaded connections with a 6 mm diameter
• Package contains one purge valve and one mounting screw

Technical Details and Specifications

The Dorman 994-157 vacuum switching valve is designed with three ports to regulate vacuum flow effectively within the emission control system. The valve’s metal construction ensures durability under various operating conditions. Its 75 mm length and specific port diameters (0.25 inches for Port 1 and 4 mm for Ports 2 and 3) allow precise fitment and function. The valve includes a single mounting hole with a 6.6 mm diameter and threaded connections sized at 6 mm, facilitating secure attachment and integration into the vehicle’s vacuum system. Two electrical terminals provide reliable connectivity for switching operations.

Compatible Vehicles and Applications

This vacuum switching valve is compatible with a range of Lexus and Toyota vehicles, including:

• Lexus ES350, RX350, RX450h
• Toyota Avalon, Camry, Highlander, Sienna, Solara, Venza

It is specifically designed to maintain proper vacuum control in the emission system, contributing to efficient purge valve operation and overall emission compliance.

Common Issues Addressed by This Vacuum Switching Valve

• Irregular or faulty vacuum switching causing emission control errors
• Check engine light triggered by purge valve malfunctions
• Reduced engine performance due to vacuum leaks or valve failure
• Failed emissions tests related to vacuum system inefficiencies
• Unstable idle or rough running conditions linked to vacuum control

Installation Notes and Tips

When installing the Dorman 994-157 vacuum switching valve, ensure the mounting hole aligns correctly with the vehicle’s bracket using the 6.6 mm diameter hole. Verify that all three ports are connected to their respective vacuum lines according to the vehicle’s service manual. The valve’s threaded connections should be securely tightened to prevent leaks. Electrical terminals must be properly connected to maintain switching functionality. It is recommended to inspect surrounding vacuum hoses for wear or damage during installation.

Quality Assurance and Warranty

Dorman parts are manufactured to meet or exceed OEM standards, providing reliable performance for emission control systems. The 994-157 vacuum switching valve undergoes rigorous quality checks to ensure durability and proper function. Please refer to Dorman’s warranty policy for specific coverage details.