- Description
- Fitment
- Refund Policy
The MMX Performance BMW Billet Coolant Expansion Cap is a precision-engineered replacement designed to improve both the durability and appearance of your BMW's cooling system. Unlike decorative cap covers, this is a complete OE replacement that fully replaces the factory plastic coolant expansion cap while retaining all factory pressure regulation and sealing functionality.
Factory coolant caps are subjected to constant heat cycles and pressure fluctuations, which can cause plastic components to degrade over time. The MMX Billet Coolant Expansion Cap addresses this with a robust construction CNC-machined from a solid block of 6061 aerospace-grade aluminum, providing superior strength, heat resistance, and long-term reliability while adding a premium OEM+ appearance to the engine bay.
Each cap is manufactured using advanced 5-axis CNC machining before receiving a durable gloss black anodized finish for excellent corrosion resistance and long-lasting appearance. The precision-machined exterior also provides improved grip, making installation and removal easier during routine coolant service.
Unlike many aftermarket alternatives, the MMX Billet Coolant Expansion Cap arrives pre-assembled with OE-spec internal components, including the pressure valve, internal spring, and high-quality Viton O-ring seal. No parts need to be transferred from the original cap, allowing for a simple direct replacement while maintaining proper cooling system pressure and sealing performance.
Available in both 60mm and 90mm versions, the MMX Performance BMW Billet Coolant Expansion Cap replaces BMW OE part numbers 17117639024 (60mm) and 17117639021 (90mm). Please verify the part number on the underside of your existing coolant cap prior to ordering.
Product Details
- MMX Performance billet coolant expansion cap for BMW
- Available in 60mm and 90mm fitments
- Replaces BMW OE part numbers 17117639024 (60mm) and 17117639021 (90mm)
- Direct OE replacement with factory-style internals pre-installed
- Pre-installed pressure valve, internal spring, and Viton O-ring seal
- CNC-machined from 6061 aerospace-grade aluminum
- Advanced 5-axis machining for precise fitment
- Gloss black anodized finish for corrosion resistance and OEM+ appearance
- Precision-machined grip design for easier installation and removal
- Improves durability compared to the factory plastic coolant cap
- No transfer of OEM components required
Recommended Products
Returns
Our policy lasts 14 days. If 14 days have gone by since your purchase, unfortunately we can’t offer you a refund or exchange. All items are subject to 15% restocking fee from the manufacturer.
To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.
Additional non-returnable items:
Gift cards
Downloadable software products
To complete your return, we require a receipt or proof of purchase.
Please do not send your purchase back to the manufacturer.
There are certain situations where only partial refunds are granted (if applicable)
You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of shipping to you will be deducted from your refund. If your original order qualified for free shipping, the actual cost of shipping the item to you will still be deducted from your refund.
If you would like to start a return please click here
Refunds (if applicable)
Once your return is received and inspected, we will send you an email to notify you that we have received your returned item. We will also notify you of the approval or rejection of your refund.
If you are approved, then your refund will be processed, and a credit will automatically be applied to your credit card or original method of payment, within a certain amount of days.
You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of shipping to you will be deducted from your refund. If your original order qualified for free shipping, the actual cost of shipping the item to you will still be deducted from your refund.
Late or missing refunds (if applicable)
If you haven’t received a refund yet, first check your bank account again. Then contact your credit card company, it may take some time before your refund is officially posted. Next contact your bank. There is often some processing time before a refund is posted. If you’ve done all of this and you still have not received your refund yet, please contact us at info@amtuning.ca.
Sale items (if applicable)
Only regular priced items may be refunded, unfortunately sale items cannot be refunded.
Exchanges (if applicable)
To start an exchange, click here
Non-refundable items
The following items are non-refundable and non-returnable once purchased: oils, fuel or oil additives, filters, tuning cables, OBDeleven products, Braum seats, spark plugs, coil packs, and similar consumable, wheel spacers, wheels bolts, license plate brackets, electronic tuning components and any other product subject to discretion of AM Tuning Canada.
Other products from brands such as MHD, Bootmod3, Ecutek, Braum racing, Novitec are also non-refundable and non-returnable.
All sales of these items are final and are subject to the policies and discretion of AM Tuning. By completing a purchase, the customer acknowledges and agrees to these terms.
