Mercedes-Benz GLS Brake Master Cylinder Replacement Parts

Yes, the GLS is a full-size SUV sold in the UK with conventional hydraulic brakes, so every variant — petrol, diesel, and hybrid — has a brake master cylinder as a core part of the braking system. This is straightforward: unlike some components that only appear on certain drivetrains, the brake master cylinder is fitted across the entire GLS range regardless of engine or trim level.

These are distinct generations built on different platforms, so the brake master cylinders are not the same part and will not interchange directly. The X166 ran from 2016 to 2019 and the X167 launched in 2019, and breakers will list them separately — always confirm the generation and registration with your breaker before ordering.

Engine size can influence brake system specification on the GLS, as heavier or more powerful variants — such as the GLS 580 or AMG GLS 63 — may carry a different master cylinder to suit uprated braking demands compared with a GLS 350d or 400d. When contacting a breaker, give them your exact engine code and registration so they can match the correct unit rather than just the model name.

Trim level on its own does not determine brake master cylinder fitment; what matters is the generation (X166 or X167) and the engine variant. AMG Line is primarily a cosmetic and interior package, so a master cylinder from the same generation and engine specification should be the relevant match regardless of trim badging. That said, always confirm the part number against your registration with the breaker, as AMG Line cars are sometimes paired with specific engine options that may affect the spec.

A 2018 GLS sits in the first-generation X166 range, while a 2020 GLS is second-generation X167, so these are different generations and the parts are very unlikely to be interchangeable. Stick to sourcing a master cylinder from another X166 (2016–2019) with a matching engine size, and confirm fitment against your registration with the breaker before purchasing.

Have your vehicle registration number ready, as this allows the breaker to confirm the exact generation, engine code, and any build-specific variations; also note whether your car is X166 (2016–2019) or X167 (2019 onwards). Engine size is particularly important — a GLS 350d diesel and a GLS 580 petrol are unlikely to share the same master cylinder — so the more detail you can provide, the better your chances of getting the right part first time.