Wells 4B1608 Evaporative Emissions System Leak Detection Pump

The Wells 4B1608 is an evaporative emissions system leak detection pump designed to monitor and maintain the integrity of your vehicle's EVAP system. This critical emissions component pressurizes the fuel vapor system to detect leaks that could allow harmful fuel vapors to escape into the atmosphere, ensuring compliance with federal emissions regulations.

Key Features:

• Pressurizes EVAP system to approximately 7.5 inches of water pressure for accurate leak detection
• Features integrated diaphragm, vent valve, reed switch sensor, and check valves for complete system testing
• Powered by engine vacuum to pump air into the evaporative emissions system
• Communicates with the powertrain control module (PCM) to detect leaks as small as 0.020 inches in diameter
• Replaces OEM part number 4891525AB and cross-references to Wells ESM1016 and ESM1018
• Direct replacement for select Chrysler applications

When the PCM initiates a diagnostic check, the leak detection pump closes the EVAP system vent valve and introduces pressurized air into the sealed system. By monitoring how quickly the system maintains pressure, the pump can identify even small leaks that would allow fuel vapors to escape. A faulty leak detection pump will trigger the check engine light and cause your vehicle to fail emissions testing, making timely replacement essential for maintaining environmental compliance and vehicle performance.