Rein WPA0037 Engine Auxiliary Water Pump

OE Quality Auxiliary Water Pump for Mercedes-Benz

The Rein WPA0037 auxiliary water pump is built to OE casting specifications for proper fit, steady coolant flow, and reliable cooling performance. It is an application-specific replacement for select Mercedes-Benz ML-Class models, including ML320, ML430, ML500, ML55 AMG, and ML350.

• High-quality plastic or metal construction for durability
• Flow rates matched to OE specifications
• Application-specific fit for easier installation
• Includes vibration isolators, mounting brackets, and hardware where applicable
• Plastic impeller material

Detailed Product Overview

Rein WPA0037 is an OE quality auxiliary water pump engineered for vehicles that require dependable supplemental coolant circulation. By following original casting specifications, this pump supports proper alignment and fitment during replacement service. The design focuses on maintaining OE-style flow characteristics, which is important for consistent temperature control in the cooling system. This part number, WPA0037, is a direct-fit style solution for Mercedes-Benz ML-Class applications where the auxiliary pump is part of the thermal management system.

Compatible With 1998-2003 Mercedes-Benz ML320, 1999-2001 Mercedes-Benz ML430, 2002-2005 Mercedes-Benz ML500, 2000-2003 Mercedes-Benz ML55 AMG, and 2003-2005 Mercedes-Benz ML350. This part cross-references Genuine 0018356064 for the same application.

Common Cooling System Issues

• Weak or inconsistent coolant circulation through the auxiliary circuit
• Cooling performance concerns during idle or low-speed operation
• Noise or vibration from a worn auxiliary pump assembly
• Fitment problems caused by non-OE-style replacement parts
• Temperature control issues related to reduced coolant flow

Installation Notes and Tips

Before installation, verify the vehicle application against the part number WPA0037 and inspect the surrounding cooling components for leaks, damaged connectors, or worn mounts. When replacing the auxiliary pump, confirm that the mounting points and coolant hose connections are clean and free of debris so the new pump seats correctly. If the original pump showed signs of contamination or overheating, inspect the system for the root cause before returning the vehicle to service.

Quality Assurance

Rein Automotive OE quality auxiliary water pumps are manufactured from original casting specifications and built with durable plastic or metal construction for long service life. Part number WPA0037 carries a 24-month, 24,000-mile warranty.