MMX 60mm billet aluminium coolant expansion tank cap for BMW and MINI
MMX 60mm billet aluminium coolant expansion tank cap for BMW and MINI
MMX 60mm billet aluminium coolant expansion tank cap for BMW and MINI
MMX 60mm billet aluminium coolant expansion tank cap for BMW and MINI
MMX 60mm billet aluminium coolant expansion tank cap for BMW and MINI
MMX 60mm billet aluminium coolant expansion tank cap for BMW and MINI
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MMX

MMX BMW & MINI 60mm Billet Coolant Expansion Tank Cap

Sale price£98.27GBP
SKU: MMR03-1503

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The MMX 60mm Billet Coolant Expansion Cap is designed from the ground up in the UK and engineered from a solid billet of aluminium as a direct replacement for the factory coolant cap. It fits BMW and MINI models running OE part number 17 11 7 639 024, and replaces that cap outright rather than covering it.


Match The Cap Diameter, Not The Model

BMW uses two common expansion tank cap sizes across its modern range, 60mm and 90mm, and they are not interchangeable. The number on the factory cap is the definitive check: this MMX cap replaces OE 17 11 7 639 024. Models running the larger 90mm cap are covered by a separate MMX part.


Pressure Retained, Finish Improved

A coolant cap is a pressure component, not a trim item, which is why MMX builds a full replacement instead of a cosmetic cover. The billet cap retains the correct system pressure and seal while removing the faded, brittle plastic that lets down an otherwise tidy engine bay.


Key Features

  • CNC-machined in the UK from solid billet aluminium
  • Direct replacement for OE part number 17 11 7 639 024
  • 60mm expansion tank fitment
  • Not an adhesive cover – the factory cap is replaced outright
  • Anodised finish for lasting corrosion resistance
  • Fully reversible – the OEM cap can be refitted at any time

Specifications

  • Part Number: MMR03-1503
  • Replaces OE: 17 11 7 639 024
  • Diameter: 60mm
  • Material: Billet aluminium, anodised

Compatibility

  • BMW and MINI models fitted with the 60mm expansion tank cap, OE 17 11 7 639 024
  • Always confirm the part number on the existing cap before ordering

Frequently Asked Questions

How is 60mm confirmed against 90mm?
Read the part number on the factory cap. 17 11 7 639 024 is the 60mm cap; 17 11 7 639 021 is the 90mm version, for which MMX offers a separate part.

Can the cap be fitted with the engine hot?
No. A cooling system should only be opened when fully cold, exactly as with the factory cap.


Why Choose An MMX Billet Cap?

Coolant caps sit in the most visible part of the engine bay and are the first component to look tired. MMX machines a full-function replacement that holds pressure properly and looks right for years. R44 Performance stocks the complete MMX under-bonnet range.

PLEASE NOTE

  • Orders with both in-stock and backorder or out-of-stock products will be dispatched once all products are available to ship together.
  • Contact our sales team if you want your parts fitted to your vehicle at our London workshop.
  • Shipping estimates are based on courier delivery times and don't include time to despatch from our warehouse.