The Power Stop K5305 is a complete rear brake upgrade from the Z23 Evolution Sport line. It pairs carbon-fiber ceramic brake pads with drilled and slotted rotors, so the pads and rotors are matched as one set for the 2008-2014 Subaru Impreza rear axle. The manufacturer describes the rotors as zinc-coated, drilled, and slotted, with precision drill holes for cooling and slots that clear gas and debris from the pad contact area. Compared with a pad-only swap, the rotors add cooling and a cleaner contact surface, which matters for drivers who make repeated hard stops on spirited back-road or weekend runs. Owners on user forums generally describe the Power Stop pads as a smooth, progressive daily-driver upgrade over stock rear brakes. Fitment is the main thing to verify before ordering, because published fitment information for this kit is inconsistent. Confirm your exact trim and VIN with the manufacturer. Searches for Z23 rear brake kit, Impreza rear rotor upgrade, and drilled slotted 2008-2014 Impreza brakes will lead to this kit.
The product title names the 2008-2014 Subaru Impreza, but published fitment tables for this kit also list WRX STI trims for those years and later WRX and WRX STI models. Fitment details vary across sources, so confirm your exact trim and VIN with the manufacturer before ordering.
Owners on user forums generally view it as a daily-driver upgrade. One enthusiast on a Subaru forum said most owners found it fine for everyday driving, while another argued that dedicated performance pads from other brands offer more for spirited or track use.
On user forums, one owner of Power Stop pads reported wear indicator contact earlier than expected and a pad backing tab that broke off. Other owners on user forums report satisfaction with the pads, so inspect pad thickness and hardware during routine service.
This is a rear pad and rotor replacement, so it is a practical weekend job for a home mechanic comfortable with brake work. Owners on user forums report that Power Stop bolt-on kits for the Impreza were not difficult to install. Before assembly, inspect the caliper slide pins and use a proper high-temperature brake lubricant rather than relying on the included supply alone, because one owner on user forums found the thin graphite lube supplied with a different Power Stop kit let the pins wiggle. Also check the rotor hat area for surface rust, which owners on user forums report can appear after a winter of road salt exposure. Confirm the torque specifications, bedding-in procedure, and required tools with the manufacturer's install sheet before starting.
