PRO BAT Rear Hydraulic Brake Assembly Caliper Master Cylinder Kit

Our review of the PRO BAT Rear Hydraulic Brake Assembly finds it best suited for owners of small Chinese ATVs, go karts and 50cc-250cc quad conversions who want a complete rear brake that arrives ready to install. The kit includes a fully assembled rear caliper and master cylinder with brake fluid and a 158mm rotor, which is the single biggest convenience - it removes the need to bench-bleed or source pads separately. For anyone replacing a rear brake on Coolster, Taotao or similar 50cc to 200cc machines, this package aims to speed up repair time.

Key Features

• Complete rear assembly: The kit ships with a prefilled rear brake assy so the system is ready to mount and helps reduce installation steps.
• Included 158mm rotor: The 158mm outer diameter rotor provides a matched braking surface for the caliper and avoids rotor sourcing delays.
• Extra brake pads: A spare pair of pads is included so you have a replacement on hand after initial bedding or if a pad is damaged.
• Hydraulic line length: The 1400mm hydraulic tubing gives enough reach for most small quad and kart rear layouts without rerouting hose extensions.
• Complete mounting hardware: Bolts and ties are included to simplify fitting the rotor and caliper to compatible swingarms or hubs.

Who It's For

This kit is aimed at DIY mechanics and small-vehicle owners who need a direct replacement rear brake for Chinese-built ATVs, go karts, drift trikes and 50cc to 250cc machines from brands like Coolster, Taotao, Kazuma and similar. It suits people who want a mostly plug-and-play solution with rotor, pads and fluid included so they can refit quickly.

It is not ideal for users who require exact OEM fitment for non-standard frames or for those who expect a performance, high-end race caliper; some customers reported mixed functionality and occasional pad retention issues, so riders who demand guaranteed high-performance stopping should consider higher-spec brake systems or professional installation and testing.

Pros & Cons

Pros

• Comes prefilled and assembled, which saves time and reduces bleed work during installation.
• Includes rotor, extra pads and mounting hardware, offering good value for the price.
• Hydraulic hose length and mounting spacings are suitable for many 50cc-200cc small ATVs and go karts.

Cons

• Functionality reports are mixed; some users find braking strong while others encountered poor performance, so testing after fitment is advised.
• There are occasional reports of brake pads not seating securely in the caliper, which may require minor adjustments or retainer checks.

Specifications

Application	Chinese ATV, go kart, golf cart, drift trike 50cc-250cc
Rotor outer diameter	158mm (6.22 in)
Rotor inner diameter	48mm (1.88 in)
Rotor thickness	9mm (0.35 in)
Hydraulic tubing length	1400mm (55.1 in)
Master cylinder mount spacing	45mm (1.77 in)
Caliper mounting hole spacing	63mm (2.48 in)

Our Verdict

This PRO BAT rear hydraulic brake kit is a practical, value-focused replacement for owners of Coolster, Taotao and similar small ATVs who want a mostly ready-to-fit rear brake with rotor and spare pads included. It offers solid convenience and value, though buyers should verify pad fitment and perform a brake test after mounting because user feedback on stopping consistency is mixed.

Frequently Asked Questions

Is this kit ready to install out of the box?
Yes, the rear brake assembly is supplied with brake fluid and brake pads installed, so it arrives ready for mounting.

Will the rotor and caliper fit my 150cc quad?
The rotor is 158mm with provided mounting hardware and the caliper has 63mm mount spacing; it fits many 50cc-250cc Chinese ATVs but confirm hub and swingarm compatibility before purchase.

Are extra pads included?
Yes, the package includes one extra pair of brake pads in addition to the pads preinstalled on the caliper.