Front Brake Master Cylinder- Hyosung GV125S EFi Bobber (Aquila 125 S)

Description

Don’t compromise on safety with a temporary fix if your front brake pump is weeping fluid or failing to hold pressure. This aftermarket front brake master cylinder provides a premium replacement assembly for your system. When you inspect the product gallery pictures, you will spot that this casting is a 99% geometric match to the factory part. The sole variation is the updated paint finish; the factory paint versus this fresh replacement uses a marginally different level of black gloss, but the structural core remains completely identical. It will support your original factory controls perfectly, making it an excellent alternative when restoring your stopping configuration.

💎 Component Properties

📜 Confirmed Fitment Guide

Hyosung Models: Fits the specific layout detailed below.

• GV125-S Aquila Bobber EFi (CBS Models Only): 2018 to 2026+ onwards.
  (Your control setup must match the reference image below)

❌ EXCLUSIONS (WILL NOT FIT):

• GV300-S Aquila Bobber: Incompatible. This higher-capacity variant utilizes a completely different internal piston configuration with a stronger hydraulic cylinder design to handle different clamping forces.
• Older GV125 Carburettor Models: Incompatible. The early handlebar configurations run an entirely different mechanical and geometric fluid tank design.
• GV125X / GV125R (ABS Variants): Incompatible. Designed strictly for non-ABS machines equipped with standard Combined Braking Systems (CBS).

🔧 Install Tips

• Protect your bodywork: Brake fluid acts like paint stripper. Cover your fuel tank, plastic panels, and painted frame tubes with heavy towels before crack-opening the banjo bolt on your old front brake pump assembly.
• Copper washer renewal: Always fit fresh copper crush washers on either side of the hydraulic line fitting during the swap. Reusing compressed washers will result in tiny, slow high-pressure fluid leaks across the sealing faces.
• System bleeding: Once the fresh front brake master cylinder is clamped down, fill it with fresh fluid from a sealed bottle and bleed the line thoroughly from the lower assembly. Ensure your lever feels completely firm before testing the bike on public paths.