Sumart UBB-40 Bleed Block & Piston Spreader, 4-Piston

The same job for 4-piston calipers: pushes the pistons back for new pads and holds them during a bleed. Adjusts by hand or with a 3 mm hex key. Sumart lists it as made in Taiwan.

From Sumart, a tool and parts maker in Taichung, Taiwan. Ships from a US warehouse.

Why we carry it: it makes a home brake job clean and repeatable instead of a fight.

Details from Sumart

Protect pistons, set the correct pad gap, and make 4-piston brake bleeding cleaner and more consistent.

The Sumart UBB-40 Universal Bleed Block is designed to simplify hydraulic brake maintenance on 4-piston calipers. Built to help hold pistons in the correct position during bleeding and service, the UBB-40 protects delicate pistons, supports proper pad spacing, and helps mechanics achieve a more consistent brake setup with less guesswork.

Whether you are servicing brakes in a professional workshop or maintaining your own bike at home, the UBB-40 is a practical tool for safer, cleaner, and more repeatable brake bleeds. Its adjustable design lets you fine-tune the fit by hand or with a 3 mm hex key, making it easier to work across a wide range of compatible 4-piston brake systems.

Key Features & Benefits

• Universal 4-Piston Compatibility: Designed to work with most major 4-piston hydraulic disc brake systems.
• Dual Adjustment Options: Can be adjusted by hand or with a 3 mm hex key for more precise positioning.
• Piston Protection: Helps prevent damage to delicate brake pistons during bleeding and maintenance.
• Correct Pad Gap Setup: Supports proper spacing for smoother brake operation and more consistent lever feel after service.
• Workshop-Ready Construction: Built for repeated brake maintenance and regular workshop use.
• Multiple Color Options: Available in a wide range of finishes to match your tools or bike build.

Why Use a Bleed Block?

A proper bleed block helps keep brake pistons correctly positioned during maintenance, which can improve bleed consistency and reduce the risk of accidental piston damage. For 4-piston brakes especially, using the correct block can make brake bleeding faster, more repeatable, and less frustrating.

Specifications

• Model: UBB-40
• Product Type: Universal bleed block / piston spreader
• Compatibility: Most 4-piston hydraulic disc brake calipers
• Adjustment: Hand-adjustable or 3 mm hex key
• Weight: 55 g
• Country of Origin: Made in Taiwan
• Color Options: Black, Red, Blue, Gold, Purple, Orange, Pink, Green

Ideal For

The Sumart UBB-40 is ideal for bike shops, home mechanics, and riders servicing 4-piston hydraulic disc brakes. It is especially useful for brake bleeding, piston resetting, and routine hydraulic brake maintenance where piston protection and consistent pad spacing matter.

If you want a cleaner, more controlled way to service 4-piston brakes, the Sumart UBB-40 Universal Bleed Block is a smart addition to your brake maintenance toolkit.