Nissin M/CYL REP Kit Rear MX 1/2

The Nissin Master Cylinder Repair Kit is a direct-replacement rebuild solution for Nissin rear brake master cylinders with a 1/2 inch bore, designed for motocross and off-road motorcycles.

Sourced from Nissin — the original manufacturer of many OEM brake systems fitted to Japanese off-road bikes — this kit allows riders and mechanics to restore proper braking performance without replacing the entire master cylinder assembly.

• Designed for Nissin rear master cylinders with a 1/2 inch bore
• Intended for MX and off-road motorcycle applications
• Manufactured by Nissin, the OEM supplier to major Japanese motorcycle brands
• Restores master cylinder function without full unit replacement

Before installation, drain and dispose of old brake fluid in accordance with local regulations — brake fluid is hygroscopic and should not be reused.
Clean the master cylinder bore thoroughly before fitting the kit; any debris or corrosion can damage new seals immediately.
Lubricate new rubber components with fresh, clean brake fluid of the correct specification before assembly — never use petroleum-based lubricants on rubber brake parts.
Inspect the master cylinder bore for scoring or corrosion before rebuilding; a damaged bore will cause premature seal failure and the cylinder should be replaced rather than rebuilt.
After assembly, bleed the rear brake system completely to remove all air from the hydraulic circuit before riding.
Check for leaks at the master cylinder reservoir, banjo bolt, and bleed nipple after the first few brake applications.
Brake fluid should be replaced at the interval specified in your motorcycle's service manual, as absorbed moisture lowers its boiling point and can cause brake fade.
Store any unused kit components in a cool, dry location away from direct sunlight and petroleum-based products, which can degrade rubber seals.