XYZ Racing Hollow Rear Brake Kit — Mercedes Benz S CLASS W221 S 550 (2005-2013)

The W221 S 550 is a near two-tonne flagship saloon, and most owners only ever think about the front axle when braking comes up. The rear is where heat builds quietly, on a long motorway descent or a loaded run down an Alpine pass with four up and a boot full. The XYZ Racing Hollow Rear Brake Kit gives the back of this S 550 the thermal capacity to do its share of the work instead of leaning on the fronts.

This is a rear-axle kit built around two-piece floating discs, designed to shed rotating mass where the standard Mercedes hardware is happy to carry it. Run alongside the matching front kit, it rebalances how a heavy long-wheelbase car sheds speed: a steadier pedal, less front-bias fade, and more composure when the car is fully loaded.

What this brake kit does for your 2005-2013 Mercedes Benz S Class W221 S 550

The first thing you feel on the W221 is pedal consistency when the car is working, as repeated stops from motorway speed no longer soften the bite. The hollow-vane disc design trims rotating weight at the rear, which an AIRMATIC-equipped S 550 rewards with cleaner body control over mid-corner bumps. Three pad compounds let you match the rear axle to how you actually use the car: Street for quiet town running, Sport for harder fast-road work with more bite and heat range, and Racing for repeated high-temperature stops. With the rear taking more of the deceleration, the front kit stops cooking on long descents and the whole car settles under braking rather than diving onto its nose. Caliper finishes from no-cost Red, Yellow, Gold, Black and Anodized Black through to premium polished-forged and candy options keep the hardware looking deliberate behind the factory wheels.

About the Hollow Rear Brake Kit

The XYZ Racing Hollow Rear Brake Kit is a rear-position upgrade for the W221 S 550, built around a two-piece floating, hollow-vane disc that reduces rotating mass without surrendering swept area. It is supplied as a pair of rear calipers and discs with a choice of three pad compounds: a Street compound for quiet, low-dust road use, a Sport compound for keener bite and warmer working temperatures, and a Racing compound built for repeated hard stops. The caliper body is hollow as standard, with an optional Hollow Racing upgrade for serious track use, rated to 1000C with no dust cover and a two-year warranty. Discs are drilled or slotted at the same price, with two-tone anodized or titanium centre bells selectable. Calipers can be specified in no-cost Red, Yellow, Gold, Black or Anodized Black, premium polished-forged Titanium, Polished Gold or Polished Silver, candy Teal, Blue, Red or Orange, or a Custom Pantone for 150 pounds, so the kit can sit discreetly or stand proud behind the factory rims. As a rear-axle kit it is engineered to work in concert with the matching front setup, correcting a car that leaves the factory with a strong front brake bias, and the hardware is sized to the S 550’s rear axle so it bolts to the chassis it was designed for.

Fitment for the Mercedes Benz S Class W221 S 550 (2005-2013)

This kit is cut for the W221-generation S Class, covering the 2005 to 2013 production span, and fits the rear axle specifically. Confirm your car is the W221 chassis and the S 550 variant before ordering, since brake hardware differs across the wider S Class range and front and rear kits are not interchangeable.

What buyers also search for

• Mercedes Benz S Class W221 rear brake upgrade for a heavy V8 saloon
• S 550 rear brake kit with Street, Sport and Racing pad compound choices
• W221 S Class rear discs that resist fade on long, loaded motorway descents
• Mercedes S 550 caliper colour options in red, yellow, gold, black or Custom Pantone
• Hollow rear brake kit to rebalance front-biased braking on a 2005-2013 S Class

Choose your pad compound and caliper colour from the options above when you build your W221 S 550 rear brake kit.