Second Hand BMW i4 Brake Servo

No – the BMW i4 is a fully electric vehicle and does not have a traditional vacuum-powered brake servo at all. Instead it uses an electro-hydraulic brake booster (sometimes called an iBooster) that generates braking assistance electronically without any vacuum from an engine. If you have been quoted for a 'brake servo', the part you are most likely looking for is the iBooster unit or the integrated brake control module – ask your breaker specifically for the electro-hydraulic brake booster for the i4.

The iBooster is the BMW i4's replacement for a conventional brake servo – it is an electrically-driven unit that provides the braking assistance a petrol car gets from engine vacuum. The two parts perform the same job for the driver but are completely different in design and are not interchangeable with traditional vacuum brake servos from petrol or diesel BMWs. When searching for a used part, search for 'BMW i4 iBooster' or 'electro-hydraulic brake booster' rather than 'brake servo'.

No – although the i4 (G26) shares its bodyshell with the 4 Series Gran Coupé, the petrol and diesel 4 Series uses a vacuum brake servo that relies on engine intake vacuum, which the electric i4 simply does not produce. The i4 uses an entirely different electro-hydraulic iBooster unit, so the two systems are not compatible. You need to source an iBooster from an i4 donor car specifically, not a combustion-engined 4 Series.

The BMW i4 was offered in eDrive40 (rear-wheel drive) and M50 (all-wheel drive) variants, and it is worth confirming with the breaker whether the iBooster unit differs between these two configurations, as the M50's higher performance and dual-motor setup may carry different brake system components. Trim level names such as M Sport do not affect the brake booster fitment – trim is a cosmetic and feature distinction, not a running-gear one. Always confirm the correct part against your specific registration with the breaker before purchasing.

The BMW i4 (G26) launched in 2022 and has not undergone a full generation change as of the time of writing, so early and later cars are broadly the same generation. However, mid-generation running-gear updates can occur without obvious external changes, so whether a 2022 or 2023 iBooster crosses cleanly to a 2024 car is something you should confirm with the breaker against your registration number rather than assume. Quoting your VIN or registration to the breaker is the most reliable way to verify compatibility within the same generation.