G4 Front Brake Caliper - Left

This front left brake caliper (passenger side on RHD cars) is a direct replacement unit for Volkswagen models fitted with the ATE single-piston front braking system. It’s designed to clamp onto vented front brake discs with a 22mm thickness, and it’s used on applications running either 256mm or 280mm diameter front discs (depending on the vehicle’s factory brake specification).

A healthy caliper is crucial for safe, predictable braking. If your caliper is sticking, leaking, or the piston is corroded, you’ll often notice pulling to one side, uneven pad wear, overheating, vibration, or a soft pedal. Replacing the caliper restores correct pad pressure and helps protect your discs and pads from premature wear.

What the caliper does

The caliper is the hydraulic “clamp” of the braking system. When you press the brake pedal, brake fluid pressure travels through the brake hose into the caliper. That pressure pushes the 54mm piston outward, forcing the inner pad against the disc. On a floating/sliding caliper (as used here), the caliper body then slides on its guide pins to pull the outer pad into the disc too, creating equal clamping force on both sides and slowing the wheel safely.  

Because the disc is vented, it cools more effectively than a solid disc—great for heavier cars and repeated braking—but it also means the caliper must match the correct disc thickness and pad profile.

Key specifications

• Position: Front axle left (Passenger side on RHD)

• System: ATE

• Type: Brake caliper (1 piston)

• Piston diameter: 54mm

• For discs: Vented, 22mm thick

• Disc diameter compatibility: 256mm or 280mm (application dependent)

Fitment (based on your list)

Commonly listed for:

• VW Beetle / New Beetle

• VW Bora

• VW Caddy III

• VW Golf IV / V / VI and Golf Plus

• VW Jetta

• VW Polo (9N / 6R)

• VW Up!

Important: This caliper is manufacturer-restricted to ATE. Many of these vehicles came with different caliper brands (ATE, TRW/Lucas, etc.), so you must match the braking system type on the car. Also, some models can have either 256mm or 280mm front discs, so confirm your disc size before ordering.

Recommended fitting parts (often required/checked)

To get the best result and avoid repeat labour, it’s worth checking/replacing the common “mates” while you’re there:

• Front brake pads (correct shape for ATE caliper)

• Caliper carrier/bracket (if not supplied with your caliper, reuse yours if serviceable)

• Caliper guide pins & rubber boots (sticking pins are a common cause of uneven braking)

• Caliper mounting bolts (many are stretch/one-time-use depending on model)

• Brake hose (replace if cracked, swollen, or seized at the union)

• Copper washers/banjo washers (if your hose uses a banjo fitting)

• Brake fluid (bleed the system after fitting; always use fresh fluid)

• Brake discs (replace in axle pairs if worn/lipped or heat-spotted)

Installation notes (best practice)

• Replace in pairs across the axle when possible (left + right) for balanced braking.

• Clean and lightly lubricate slider points with a proper brake grease (never on friction surfaces).

• After bleeding, check for leaks, confirm pedal feel, and bed pads in correctly.