
XYZ Racing Hollow Rear Brake Kit — Opel ASTRA H GTC (2004-2009)
SKU: XYZ-BRK-BKR-OP-A001-REAR
- IncludesRear axle pair (2 discs + 2 calipers)
- PositionRear
- Disc Ø380–421 mm
- Caliper pots8-pot
- Lead time10–15 working days
Fits Opel ASTRA H GTC (2004-2009)
Added to basket ✓
Caliper render for this kit:

The front-wheel-drive Astra H GTC carries most of its mass over the nose, which leaves the rear axle doing the quieter half of the braking job – right up until you lift and trail the brake into a corner. That is exactly where the factory rear setup runs short of bite and consistency, and where a tail-happy three-door starts to feel vague. The XYZ Racing Hollow Rear Brake Kit for the Opel Astra H GTC (2004-2009) gives the back axle the thermal headroom and pedal feel to keep the car settled when you ask it to rotate.
This is rear-axle hardware built for fast-road and track-day use, not a cosmetic dress-up. As a rear kit it is a matched pair of left and right calipers with two uprated discs. The hollow-vane disc construction trims rotating weight and helps move heat out of the rotor, while a choice of Street, Sport and Racing pad compounds lets you match the kit to how hard the car actually gets driven.
What this rear big brake kit does for your 2004-2009 Opel Astra H GTC
Fit the kit and the first thing you feel is a firmer, more progressive rear pedal under repeated stops. On a nose-heavy GTC, stronger and more consistent rear braking sharpens turn-in and helps the car tuck in on the way into a corner instead of washing wide. The Racing pad compound holds its bite through back-to-back laps where standard rear discs would start to fade, while the Street compound keeps cold bite and low dust sensible for daily road miles and the Sport pad bridges the two for spirited driving. Larger hollow-vane rear rotors shed heat more readily, so braking stays predictable on a long Alpine descent or a busy circuit session. With a free choice of Red, Yellow, Gold, Black or Anodized Black calipers – and premium finishes if you want them – the hardware also looks deliberate behind an open wheel.
About the Hollow rear brake kit
The XYZ Racing Hollow rear brake kit is a bolt-on upgrade for the rear axle of the Astra H GTC, swapping the modest factory discs and calipers for a larger, more heat-tolerant assembly. The hollow-vane rotor matters most here: removing material from the disc cuts rotating and unsprung weight and opens up paths for heat to escape, which is what keeps a rear brake honest under sustained load. The rotors are two-piece floating discs fed by braided lines, so the pedal stays firm and the disc face stays flat as temperatures climb. Painted caliper finishes are included at no extra cost in Red, Yellow, Gold, Black and Anodized Black; for an added £150 you can specify a Custom Color in any Pantone, and premium polished-forged Titanium, Polished Gold and Polished Silver or candy Teal, Blue, Red and Orange options are available too. Pad choice spans three compounds: Street for quiet, dust-light road manners, Sport for a sharper fast-road bite, and Racing for circuit work where heat management and repeatability matter most. Calipers are hollow-bodied as standard, with an optional Hollow Racing upgrade (no dust cover, rated 1000C, two-year warranty) for hard track use. Discs are drilled or slotted at the same price, and two-tone anodized or titanium centre bells can be added at checkout. As a rear-only kit, it is designed to balance the car front to rear, complementing a front big brake upgrade rather than overloading the nose.
Fitment for the Opel Astra H GTC (2004-2009)
This kit is cut for the Opel Astra H GTC, the three-door coupe-bodied version of the Astra H, covering the 2004 to 2009 model years. It mounts to the rear axle and is supplied as a rear-only kit, so it pairs naturally with a matching front setup for balanced braking. Confirm your build year falls within the 2004-2009 span, then choose your caliper colour and pad compound before ordering.
What buyers also search for
- Opel Astra H GTC rear brake upgrade for fast-road and track-day use
- Astra H GTC big brake kit with Street, Sport and Racing pad compound options
- Opel Astra H GTC rear calipers in Red, Yellow, Gold, Black or Anodized Black
- Hollow rear brake kit to balance braking on a front-heavy Astra H GTC
- Opel Astra H GTC 2004-2009 rear brake conversion that resists fade under repeat stops
Pick your caliper colour and pad compound from the options above and build your Opel Astra H GTC rear big brake kit.
What’s in the kit
Rear axle kit — supplied as a complete bolt-on assembly.
- 2×Two-piece floating discs — 380–421 mm: you pick the exact diameter with the "Disc size" option
- 2×Lightweight aluminium centre bells
- 2×Forged aluminium calipers — 8-pot
- 2×High-stiffness mounting brackets
- 2×Braided stainless steel brake lines
- 4×High-performance brake pads (1 set)
- 1×Fitting hardware & tools pack
Parking brake: OE handbrake not retained — a hydraulic handbrake is required.
Choosing your spec
Every kit is built to order around the choices you make above. Here is what each option actually changes, so you can spec yours with confidence.
Brake pads — Street, Sport or Racing
Every kit ships with a full set of high-performance pads; the compound is your call.
Street is the right default for fast-road driving — a strong, progressive cold bite with low noise, low dust and long disc life. Sport raises the working temperature and adds bite and fade resistance for hard road use and the occasional track day, while still behaving on a cold morning. Racing is a track compound built for sustained abuse: huge fade resistance and bite once heat is in it, at the cost of more noise and dust when cold. Match the pad to how hard you actually use the brakes — there is no benefit to a race pad that never gets up to temperature.
Caliper grade — Hollow vs Hollow Racing
Hollow is the standard caliper on every kit: a hollow-body forged caliper, lighter than a solid one, fitted with a dust cover and backed by a 5-year oil-leak warranty. For most fast-road and spirited track use it is all the caliper you need.
Hollow Racing is the track-grade upgrade. It runs the same hollow body but without a dust cover (so there is nothing to melt at sustained high temperature), uses a twin-metal piston that isolates heat travelling from the disc to the oil seal, and is rated to 1000°C. Available 330–356mm (rear). Warranty is 2 years on oil leaks and 10 years on appearance. Built for professional racing and repeated track days.

Caliper colour & finish
Painted colours (Red, Yellow, Gold, Black, Anodized Black) are included at no cost. Want an exact match to your car? Custom Color (+£150) paints the calipers to any Pantone code you supply (15–20 day lead time).
Polished Forged finishes are the flagship: a forged caliper given a mirror-polished surface treatment that shifts colour with the viewing angle. Beyond the looks, the polished surface dissipates heat better, resists rust and stands up to the weather. Choose Titanium (neochrome, +£350), Polished Gold (+£300) or Polished Silver (+£250). They look their best paired with a titanium centre bell. Care: clean only with a dilute neutral cleaner or water.
Candy colours (+£200) use a deep candy-paint and polishing process for a mirror-reflection, boutique finish — pick Teal, Blue, Red or Orange (shown below right).


Centre bells
The centre bell is the CNC-machined aluminium hat that joins the disc to the hub. The standard anodized centre bell is included. The Two-tone bell (+£200) adds an anodized accent ring — choose Red, Yellow, Orange, Purple or Silver right here at checkout. The Titanium centre bell (+£500) is a forged titanium bell (bolts not included) that finishes off the polished-forged look.

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