AP Racing CP9542 Rear 4-Piston Big Brake Kit
- AP Racing
- Rear
- 4-piston
- Street
- Passenger Car
We'll confirm the exact color with you before we build the kit.
- Complete AP Racing kit — everything for one axle
- Checked against your car before it ships
- Warranty & returns
- Installation help
- Built to order — ships in about 15 business days
About this kit
A complete rear big brake kit for the BMW X3 M F97, BMW X4 M F98, BMW X5 M F95 and more. It uses two AP Racing CP9542 4-piston calipers and a pair of rotors (355–380 mm) in high-carbon steel or carbon-ceramic, plus pads, braided lines and mounting hardware.
We match the mounting brackets to your car. You'll need at least 18-inch wheels with enough room for the caliper. Not sure? Send us your wheel details.
You choose the rotor size, rotor material and caliper color. Calipers come in Gray, or in a custom color.
Built to order. It ships in about 15 business days.
Fits these cars
- BMW X3 M F97 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- BMW X4 M F98 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- BMW X5 M F95 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- BMW X6 M F96 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lexus NX200 AZ10 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lexus NX200 AZ20 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lexus NX200t AZ10 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lexus NX200t F SPORT AZ10 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lexus NX300 AZ10 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lexus NX300 F SPORT AZ10 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lexus NX300h AZ10 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lexus NX300h F SPORT AZ10 Recommended rotor size by kit: CP9542 Ø380 × 28 mm (at least 19-inch wheels).
- Lynk & Co 09 EM-P
- Lynk & Co 09 MHEV
- Lynk & Co 09 PHEV
- Lynk & Co 10 EM-P
Kits are matched to the cars listed by make, model and years. Wheels, hubs and trim levels can still differ, so check your car and wheels before you order, or ask us.
Car not listed? Ask us →Specifications
| Brand | AP Racing |
|---|---|
| Part type | Big Brake Kit |
| Axle position | Rear |
| Piston count | 4 |
| Caliper mounting | Vehicle-specific bracket mount |
| Rotor Material | High-Carbon Steel, Carbon Ceramic |
| Rotor Size | Ø355 × 28 mm, Ø380 × 28 mm |
| Caliper Color | Gray, Custom Color |
| Minimum wheel size | 18" |
| Pad compound (included) | M-01 |
| Caliper material | Forged aluminum alloy |
| Caliper bracket | High carbon steel, CNC-machined |
| Brake lines | Three-layer reinforced construction, PTFE inner liner / SUS304 stainless-steel braid / PVC protective outer sheath |
| Intended use | Street |
| Vehicle class | Passenger Car |
| SKU | AP-CP9542-CI-355X28-GRY |
| Lead time (approx.) | 15 business days |
Brake pad compounds
| Compound | Intended use | Rotor | Max temp | Avg μ |
|---|---|---|---|---|
| M-01 · STREET included | Street — daily driving and commuting | High-Carbon Steel | 600 °C | 0.38 |
| M-02 · STREET+ | Street+ — spirited road driving | High-Carbon Steel | 650 °C | 0.42 |
| M-03 · CCB+ | Carbon-ceramic rotors only — street and track | Carbon Ceramic | 750 °C | 0.44 |
Pad compound is matched to the rotor material you select. Iron-compatible pads must not be fitted to carbon-ceramic rotors, or the other way round.
What's in the box
- Brake calipers × 2
- Brake pads (one axle set) × 4
- Brake rotors × 2
- Stainless-steel braided brake lines × 2
- Vehicle-specific caliper mounting brackets × 2
- Mounting hardware × 1 set
About the brand
AP Racing
British brake and clutch specialist from Coventry, founded 1968, with one of the longest records in professional motorsport. CP-series calipers are the basis of its road-going big brake kits.
All AP Racing kits →Common questions
Will it fit my wheels?
Big calipers need room inside the wheel. Check the minimum wheel size in the specifications. If you're not sure, send us your wheel make and size and we'll check.
Do I need new brake lines or fluid?
Braided lines come with the kit. You'll need fresh DOT 4 fluid and a full bleed after fitting.
Can I fit it myself?
If you're used to brake work and have a torque wrench, yes. If not, have a workshop fit it. Our installation page covers the basic steps and bed-in.
Similar kits
Not sure what fits?
Send us your car and wheels. We'll tell you what fits.
Year, make, model, wheel size, and whether it's for the street or the track. We reply by email within one business day.