Mercedes-Benz GLA Big Brake Kit Upgrade / TTSPORT Slim SL6
This Mercedes-Benz GLA owner is a mountain-road regular who cares about pedal feel as much as lap times — but he wasn't willing to swap his factory wheels or bolt on flange adapters just to get a bigger brake. Most six- and four-piston kits on the market demand one or the other, which adds cost and introduces fitment compromises. He landed on the TTSPORT Slim Series SL6, a kit built specifically to clear OEM wheels without spacers.
The GLA runs 18-inch factory wheels, and the owner wanted a caliper that would tuck in behind them exactly as delivered. The SL6's slim forged body was designed around that constraint — no relocation brackets, no wheel upgrade required.
Vehicle & Kit Specs
Here's the hardware breakdown for this GLA front-axle install:
| Item | Specification |
|---|---|
| Vehicle | Mercedes-Benz GLA, factory 18-inch wheels |
| Front caliper | TTSPORT SL6 — Slim Series, six-piston, radial-mount |
| Front rotor | TTSPORT 355mm rotor |
| Bracket | Vehicle-specific custom caliper bracket |
| Pads / lines | TTSPORT high-performance brake pads, stainless steel brake lines |
| Hardware | Brake fluid, mounting bolts, and fasteners |
The SL6 caliper used in this build carries the following factory specifications:
| Brake Caliper | |
|---|---|
| Series | Slim Series |
| Model / Application | SL6 |
| Axle Position | Front |
| Piston Count | 6-piston |
| Piston Type | One-piece heat-insulated pistons |
| Piston Diameter | 28 mm × 2 / 30 mm × 2 / 36 mm × 2 |
| Caliper Dimensions | L 350 mm × W 135 mm × H 120 mm |
| Total Piston Area | 46.8 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 3.60 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 17 in or larger |
| Recommended Rotor Size | Ø330–355 mm × 28 mm |
| Fitment & Installation | |
| Minimum Spoke Clearance (mm) | 82 |
| Caliper Mounting Type | Radial mount with vehicle-specific caliper brackets |
| Brake Line Fitting Type | Vehicle-specific fittings; caliper-side and chassis-side fittings vary by application |
The full front kit ships as a set: SL6 calipers, 355mm rotors, a vehicle-specific bracket, pads, stainless lines, fluid, and mounting hardware — everything needed to complete the swap without sourcing extra parts.
Why It Works
- The SL6 caliper's slim forged profile was engineered around the GLA's 18-inch wheel spoke clearance and inner barrel geometry, so it fits with no flange adapter, wheel swap, or spacer.
- Piston sizing was tuned to stay matched with the factory master cylinder, so the pedal keeps a linear, predictable initial bite instead of feeling grabby or overboosted.
- The opposed six-piston layout spreads clamping force evenly across the pad, which helps resist the fade that shows up after repeated hard stops on a mountain descent.
The goal here isn't just more stopping power — it's a caliper that stays quiet and smooth around town, then holds its composure when the driving gets aggressive, all while keeping the GLA's factory look intact.
Installation Gallery
FAQ
Does the TTSPORT SL6 kit fit the Mercedes-Benz GLA's factory 18-inch wheels?
What rotor size does the SL6 kit use on the GLA's front axle?
Is this a front-only kit, and what else is included?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.