Dorman 902-5502 Engine Coolant Reservoir Cap

Engine Coolant Reservoir Cap Replacement

Dorman 902-5502 is a direct replacement engine coolant reservoir cap for vehicles that need a precise OE-style fit. It is built with a metal body, a 58.42 mm diameter, and a twist-on attachment for a secure seal on pressurized coolant tanks.

Use this cap when the original reservoir cap is cracked, missing, or no longer sealing correctly. This part is a practical replacement for applications that call for a natural-finish, non-vented coolant tank cap, including select BMW and Mercedes-Benz models.

Key Features

• Direct replacement coolant reservoir cap for pressurized cooling systems
• Metal construction for a durable, OE-style fit
• 58.42 mm diameter with twist-on attachment type
• Non-vented design with no pressure release lever
• Natural finish and compact profile for clean installation
• Part number 902-5502 for easy identification

Detailed Product Overview

Dorman 902-5502 is engineered to replace a damaged or lost engine coolant reservoir cap without changing the original system layout. The cap is pressurized and designed to maintain the cooling system seal required by the reservoir, helping the tank hold pressure as specified by the vehicle application. This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

For buyers searching for a BMW coolant reservoir cap replacement or a Mercedes-Benz coolant tank cap, this part number 902-5502 provides a focused OE-style solution. It is also a useful match for long-tail searches such as pressurized coolant reservoir cap 58.42 mm twist-on metal replacement and engine coolant tank cap for select BMW and Mercedes-Benz vehicles.

What This Part Helps Address

• Cracked coolant reservoir cap
• Lost or missing expansion tank cap
• Coolant system pressure loss from a worn seal
• Improper cap fit on a twist-on reservoir neck
• Cooling system service needs on select BMW and Mercedes-Benz applications

Installation Notes and Tips

Confirm the reservoir neck diameter, attachment style, and pressure rating before installation. This cap uses a twist-on design and does not include a pressure release lever or vent, so it should be matched to the original tank specification. Inspect the reservoir sealing surface and surrounding cooling system components before installing part number 902-5502.

Quality Assurance

Dorman designs replacement parts to match original equipment form and function where specified. Part number 902-5502 is built as a direct replacement coolant reservoir cap for the listed application type, with metal construction and pressurized operation for dependable fitment.