587221/A – Minor Kit, Front M/C (Front Brake Master Cylinder Repair Kit) for Himalayan 411 (BS4), Interceptor 650, Continental GT 650 (ByBre/Brembo type) – Genuine Royal Enfield

The genuine Royal Enfield 587221/A – MINOR KIT, FRONT M/C is the factory service kit for the front brake master cylinder used on the Himalayan 411 BS4 and on the 650 Twin family (Interceptor 650 & Continental GT 650) that run the same ByBre/Brembo-style front master. The official Himalayan BS4 parts catalogue shows it directly under the “Front Brake Master Cylinder” group, while multiple dealer/export pages sell the exact same number as “MINOR KIT – FRONT M/C 587221/A” for the 650s — that gives us two independent confirmations, so we list only those bikes here.

A “minor kit” is what you use when the master still works but has started weeping, losing lever feel, or pulling in air: you refresh the internal rubber parts and small hardware instead of buying the whole master. Because this is OEM, the seals, cup, and tiny bits match the piston/bore in your RE master perfectly — no guessing sizes. Fit it whenever you see fluid around the lever, the lever slowly creeps, or you’re doing a preventive brake overhaul on a Himalayan/650.

Key Features

• Genuine Royal Enfield service part – 587221/A MINOR KIT – FRONT M/C. 

• Correct seal sizes for the ByBre/Brembo-style master used on Himalayan BS4 and 650 Twins. 

• Fixes small leaks, soft lever, and minor internal wear without replacing the whole master.

• Plug-and-play: no machining, no non-RE rubber.

• Ideal mid-life brake refresh to restore safety and lever feel.

• Supplied as one kit; 1 kit = 1 master cylinder.

Compatibility Table (confirmed only)

CHECK PART NUMBER BEFORE PURCHASE 

Variants

• 587049/A – Major Kit, Front M/C – for full rebuild when bore/piston are worn. 

• 594706/A – UCE-oriented minor kit (different family; don’t mix). 

FAQs

Q1. What’s inside a “minor kit”?
All the small wear parts/seals for the master cylinder so you can stop a leak and restore lever feel without buying a whole master.

Q2. How do I know I need it?
Lever slowly sinks, fluid weeps at the lever/piston, or the bike sat long and the cup seal hardened.

Q3. Can I use this on a Classic 350 UCE?
❓Not fiche-confirmed. Classic/UCE usually use the 594706/A family. Match the bike’s master number before shipping. 

Q4. Do I have to bleed the brakes after fitting?
Yes — anytime you open the master, bleed the front brake circuit.

Q5. My master is badly scored.
Then use the major kit 587049/A or replace the complete master; the minor kit can’t fix damaged bores.