Slotted kit image for BKLX050-437SOSpecial order · Estimated lead time: typically 2-4 weeks
98-05 Lexus GS400 – Rear 4 Piston Big Brake Kit w/ 13 in. Slotted Rotors - Supercomp
Choose year, make and model to confirm this application-specific product fits — you can add it to your cart either way.
Verify fitment- Two 4-piston Supercomp calipers (rear axle)
- Two 13 in two-piece slotted rotors with aluminum center bells
- SC5 street brake pads
- Stainless-steel braided brake lines
- CNC-machined caliper mounting brackets and hardware
One approved application: 1998–2005 Lexus GS400 · JZS161
Choose an available option for each required item to enable Add to cart: Choose Caliper Color, Street or Race Pads, Center Bell Upgrades. Options marked “Contact for quote” require a KSport quote and cannot be added directly.
- Ships from Mesa, AZ
- 12-month limited warranty
- Special order: typically 2-4 weeks
Specifications — BKLX050-437SO
Product details
Fitted to the rear axle of a 1998 to 2005 Lexus GS400 (JZS161), this Supercomp kit pairs four-piston billet aluminum calipers with 13 inch (330 mm) slotted two-piece rotors. It is aimed at owners who have already sorted the front brakes, or who plan a front kit too, and want the rear to carry its share when braking hard.
The calipers are forged from one solid piece of aerospace-quality aluminum, and the aluminum center bells hold floating rotor rings that self-center in the caliper. That arrangement is described as lowering drag and improving pad contact. The box includes SC5 street pads, stainless braided lines, CNC-machined carbon steel brackets, hardware and an owner's manual, so no additional parts are needed for a bolt-on job.
Choose a caliper finish, pad type and center bell trim on the page. Slotted rotors favour track days; cross-drilled ones are described as cooler for daily use. As a starting rule, 17 inch wheels or larger are needed, subject to the KSport template check. GS300 and GS430 appear in the compatible list, but confirm with the fitment checker.
Supported features
One-piece construction from a solid billet of aerospace-quality aluminum rather than cast or welded, for even thickness and strength across the caliper block.
The outer section shifts slightly as needed for better self-centering in the caliper, lowering brake drag and boosting performance through more even application.
Calipers, floating brake discs, SC5 street pads, owner's manual, and all required hardware come standard.
CNC-machined carbon steel brackets let the larger calipers bolt to the OEM caliper bracket location.
Cross-drilled rotors run cooler for daily-driven vehicles; slotted rotors are recommended for more track use.
DOT-compliant stainless braided lines stop expansion under pressure for quicker response and a firmer pedal than stock rubber lines.
Standard painted orange, red, black, and yellow; premium high-polish silver, gold, and titanium; glassy and hard-anodized finishes; over 20,000 custom colors on request.
Compatible applications (3)
Choices for this kit
This part number ships with slotted rotors. Slotted suits track use; the cross-drilled version of this kit suits daily driving. Both versions are listed on the Supercomp page.
Painted KSport orange, race red, caution yellow or jet black at no extra charge. Premium high-polish, glassy and hard-anodized finishes cost extra.
Street pads are standard; race pads, titanium or twin-colour anodized center bells are optional upgrades.
Choose the caliper finish, pads and center-bell configuration above. Every selection and any extra charge is shown before Add to Cart and saved with the order. Contact KSport for a custom color quote.
Installation
Bolt-on installation with the supplied brackets; no vehicle modification on most applications. After fitting, bed the pads in: on a clear road, ten light-to-medium stops from 30–45 mph, three seconds each, at least a quarter mile apart. Some noise before the brakes warm up is normal for big brake kits.
Brake system support and bed-in procedureWarranty & service
12-month limited warranty to the original purchaser against defects in materials and workmanship. Racing use, exterior finish and improperly installed or modified parts are not covered; keep your original invoice for any claim. Small surface cracks on cross-drilled rotors are normal wear and not a defect. Replacement pads, rotors, lines and hardware are sold individually.
Warranty terms and service requestsOther published pages for MPN BKLX050-437SO
These page names share this MPN; they do not confirm fitment. Verify your vehicle before ordering.