Vaico V30-1637 Engine Coolant Reservoir Cap

Engine Coolant Reservoir Cap for Mercedes-Benz

The Vaico V30-1637 engine coolant reservoir cap is a direct-fit replacement for select Mercedes-Benz ML-Class applications. Built to match the listed dimensions and reservoir interface, it helps maintain proper sealing at the expansion tank and supports stable cooling-system pressure.

VAICO is the brand line used for application-focused replacement parts, with attention to fit, form, and OE-style serviceability. For buyers searching for a Mercedes-Benz ML320 coolant reservoir cap, ML430 expansion tank cap, or ML500 coolant reservoir cap, this part number V30-1637 is a targeted option.

• Brand: Vaico / VAICO
• Part number: V30-1637
• Height: 27.7 mm
• Length: 84.2 mm
• Width: 84.2 mm
• Weight: 0.065 kg
• Designed for expansion tank / reservoir applications
• Cross-reference: Anchor 10258, Four Seasons 38801

Detailed Fitment and Function

This coolant reservoir cap is used to seal the expansion tank and help preserve the cooling system’s operating pressure. Proper cap function is important for consistent coolant retention and for reducing pressure loss at the reservoir. The Vaico V30-1637 is listed for Mercedes-Benz ML350, ML500, ML320, ML55 AMG, and ML430 applications across the model years shown below.

• Fits 2003-2005 Mercedes-Benz ML350, N/A; Grade: Aftermarket; Compatible with Expansion Tank.; VAICO
• Fits 2005 Mercedes-Benz ML500, N/A; Grade: Aftermarket; Compatible with Expansion Tank.; VAICO
• Fits 2002-2004 Mercedes-Benz ML500, N/A; Grade: Aftermarket; Location-Expansion Tank; Location-Reservoir; VAICO
• Fits 2000-2003 Mercedes-Benz ML320, N/A; Grade: Aftermarket; Compatible with Expansion Tank.; VAICO
• Fits 2000-2003 Mercedes-Benz ML55 AMG, N/A; Grade: Aftermarket; Compatible with Expansion Tank.; VAICO
• Fits 2000-2001 Mercedes-Benz ML430, N/A; Grade: Aftermarket; Compatible with Expansion Tank.; VAICO
• Fits 1998-1999 Mercedes-Benz ML320, N/A; Compatible with front suspension stabilizer bar link kit, brake hydraulic hose, and steering tie rod end installations.; VAICO
• Fits 1999 Mercedes-Benz ML430, N/A; Compatible with front suspension stabilizer bar link kit, brake hydraulic hose, and steering tie rod end installations.; VAICO

What This Part Helps Address

• Coolant loss at the expansion tank cap
• Pressure leakage at the reservoir seal
• Cap wear that affects cooling-system sealing
• Service replacement for a damaged or aging reservoir cap
• Fitment-specific replacement needs for Mercedes-Benz ML320, ML430, and ML500 models

Installation Notes and Tips

Confirm reservoir neck style and dimensions before installation. Inspect the sealing surface on the expansion tank for cracks, distortion, or debris, and replace the cap only after the mating surface is clean and dry. Verify the cap seats fully and locks in place without cross-threading or binding.

Quality Assurance

VAICO replacement parts are built for application-specific fitment and OE-style service use. This part is identified by part number V30-1637 and is listed with direct cross-references for the same application.