HIAORS Rear Disc Brake Master Cylinder & Caliper Assembly for 50–125cc Chinese ATVs — 550mm Hose, Pre-filled DOT3

HIAORS rear disc brake master cylinder and caliper assembly is a complete replacement rear braking unit designed to restore reliable hydraulic stopping power to a wide range of 50–125cc Chinese ATVs and quads.

This kit combines a master cylinder, hydraulic brake caliper, preinstalled brake pads, DOT3 brake fluid and an extra pair of replacement pads so you can install and ride with confidence. Built for common Chinese small-displacement ATVs from brands such as TaoTao, Coolster, Roketa, Baja, Kazuma, Lifan and more, the assembly is sized to match typical mounting patterns and includes 550 mm (21.5") tubing to reach rear brake points without modification.

Will this rear brake assembly fit my ATV model?

The HIAORS assembly is made to be compatible with many popular Chinese 4-wheelers in the 50–125cc range. Measure your master cylinder and caliper mount centers and compare them to the listed sizes to confirm fitment before ordering.

• Master cylinder mount center: 35–56 mm (1-3/8" to 2-3/16")
• Brake caliper mount center: 63 mm (2.5")
• Brake tubing length: 550 mm (21.5") to reach most rear brake locations
• Common compatible brands: TaoTao, Coolster, Apollo, Vitacci, Roketa, Baja, Kazuma, Lifan, and others

What components come with the HIAORS rear brake kit?

This is a nearly complete rear brake solution delivered ready for installation. The package includes the hydraulic master cylinder, rear caliper, brake tubing, one set of pads installed, one spare pair of replacement pads, and DOT3 brake fluid pre-filled to simplify bleeding and setup.

• 1 x rear master cylinder with reservoir and lever
• 1 x hydraulic disc caliper with pads installed
• 1 x pair of replacement disc brake pads
• Pre-filled DOT3 brake fluid and connecting brake hose (550 mm)
• Fasteners and basic hardware for common mount patterns (verify before install)

How durable and reliable is the construction?

HIAORS uses quality materials suited for light off-road and recreational ATV use, and the kit ships with installed pads and brake fluid to reduce initial wear issues. Regular inspection and correct bedding of new pads will help maintain performance and extend component life.

• Caliper and cylinder machined for corrosion resistance and proper sealing
• Pads preinstalled and an extra spare set supplied for quick replacement
• Factory-checked hydraulic fill with DOT3 to reduce initial air in the line
• Recommended simple maintenance: pad inspection, fluid level check, and periodic bleeding

How difficult is installation for a DIY mechanic?

Installation requires basic mechanical skills and tools for brake lines and mounting bolts. If you have experience changing brake components or working on small ATVs, the job is straightforward; otherwise consult a local mechanic to ensure proper bleeding and safe setup.

• Tools needed: wrench set, brake bleeding kit, torque wrench, and basic hand tools
• Estimated time: 1–2 hours for a competent DIYer
• Important: confirm mounting hole spacing before purchase to avoid modifications
• After install: bed the new pads with controlled stops to seat them correctly

Who this is for: This rear brake assembly is aimed at owners of small-displacement Chinese ATVs (50–125cc) who need a reliable replacement or upgrade for worn or leaking rear hydraulic brake systems. It's ideal for riders who want a mostly complete kit that reduces parts sourcing and includes spare pads and pre-filled DOT3 fluid. If you operate a recreational quad from brands such as TaoTao, Coolster, Roketa, Baja, Kazuma or Lifan and you can verify the mounting dimensions match your frame and caliper brackets, this HIAORS kit offers a practical, cost-effective path back to consistent rear braking performance.