Royal Enfield UCE Rear Brake Caliper Assembly – Thunderbird 350/500 & Compatible Classic 500 – 594054/B

Genuine Royal Enfield rear hydraulic brake caliper assembly for compatible UCE motorcycles with the factory rear-disc braking system. The current genuine service reference is 594054/B – REAR CALIPER ASSY.

The earlier factory reference 594054/A is explicitly shown in current Royal Enfield genuine-parts databases as being replaced by 594054/B. Buyers searching for 594054, 594054/A or 594054/B are therefore looking at the same rear-caliper service family, but the current SKU should be matched before dispatch.

Part Identification

What Is 594054/B?

594054/B is the genuine Royal Enfield rear brake caliper assembly used on compatible UCE-generation motorcycles equipped with the relevant rear-disc brake system.

The caliper converts hydraulic pressure from the rear master cylinder into clamping force at the rear brake disc through the brake pads. Customers may search for this part as a rear brake caliper, rear disc caliper, rear caliper body, rear brake calliper, Thunderbird rear brake caliper or Classic rear disc caliper.

This is not the rear master cylinder, not the rear brake disc and not merely a brake-pad kit.

Confirmed Factory Fitment – Thunderbird 350 & 500

The original Thunderbird 350/500 factory parts catalogue places 594054/A directly in the Rear Caliper Assembly - BBI section with quantity 1 for both motorcycles. Current genuine-parts data supersedes 594054/A to 594054/B.

Confirmed Classic 500 Applications

Current genuine Royal Enfield assignment data for the 594054/A → 594054/B caliper family includes several Classic 500 rear-ABS / rear-disc configurations, including:

• Classic 500 Gunmetal Grey
• Classic 500 Pegasus
• Classic 500 Euro 4
• Classic 500 Redditch
• Classic 500 Stealth Black

These applications should still be checked by exact VIN, rear-brake configuration and current EPC because Royal Enfield used different brake hardware across generations and markets.

Additional Market-Cross-Referenced Applications – Verify Before Ordering

Indian specialist sellers additionally cross-list the older 594054/A caliper for certain Classic 350 UCE rear-disc/BS4, Bullet 500 BS4 and Thunderbird X 500 BS4 applications.

These broader applications are useful search references, but they are not promoted as universal confirmed fitment in this listing. For these motorcycles, confirm the exact existing caliper, VIN/EPC and rear-brake setup before dispatch.

Important Rear Disc / Drum Brake Check

This is a hydraulic rear-disc brake caliper. It cannot be used on a motorcycle configured with a rear drum brake simply because the model name is the same.

Before ordering, confirm:

• The motorcycle has a factory rear-disc brake.
• The current EPC calls for 594054/A, 594054/B or a confirmed supersession.
• The caliper mounting bracket and rear disc arrangement match.
• The hose / banjo connection arrangement is correct.
• The motorcycle has not been converted using non-standard brake parts.

594054/A vs 594054/B

This Shopify listing uses the current replacement SKU 594054/B. The older 594054/A and base 594054 numbers are retained in the description and tags so customers searching the old number can find the correct service family.

Related Rear-Caliper Service Parts

The original Thunderbird rear-caliper parts catalogue lists several service components around the 594054/A caliper family:

Complete Caliper vs Brake Pad Kit

A worn set of brake pads does not automatically require replacement of the complete caliper. Use a complete 594054/B assembly when the caliper body, piston bore, mounting/sliding system or complete unit is damaged or uneconomical to repair.

If only the friction material is worn and the caliper itself is healthy, the correct rear brake-pad kit may be the appropriate service item instead.

When Should the Complete Rear Caliper Be Replaced?

• Caliper body is cracked or physically damaged.
• Piston bore is badly corroded or scored.
• Caliper has sustained accident damage.
• Bleeder / hydraulic threads are damaged beyond safe repair.
• Mounting or sliding-pin area is damaged.
• Persistent brake-fluid leakage remains after correct diagnosis.
• Caliper remains seized after proper inspection and service is not economical.
• The exact Royal Enfield repair requirement specifies a complete 594054-family assembly.

Brake Safety – Diagnose Before Ordering

A dragging, weak or spongy rear brake does not automatically mean the complete caliper is faulty. Check the entire rear hydraulic brake system, including:

• Brake pads
• Caliper piston and seals
• Sliding / guide pins
• Rear brake disc
• Rear master cylinder
• Brake hose
• Banjo connections and sealing washers
• Brake fluid condition
• Air in the hydraulic system
• Brake pedal linkage

Brakes are safety-critical. Professional diagnosis and installation are strongly recommended.

What You Receive

• 1 × Genuine Royal Enfield Rear Brake Caliper Assembly
• Current SKU: 594054/B

What Is Not Included Unless Physically Supplied in the Genuine Pack?

• Rear brake disc
• Rear master cylinder
• Brake hose
• Banjo bolt / copper sealing washers
• Brake fluid
• ABS sensor
• ABS tone ring
• Wheel / hub components
• Separate caliper service kits
• Mounting fasteners not packaged with the genuine caliper

Brake Pads / Package Contents Note

Do not assume that every genuine replacement-caliper package contains separate service brake pads or every small external fitting shown in the motorcycle EPC. Royal Enfield service-kit packaging can change over time.

The sealed genuine package and dealer invoice are the final authority for physical kit contents. If pad inclusion is critical to the order, confirm the actual boxed item before dispatch.

Installation Notes

• Confirm the exact motorcycle, rear-disc configuration and part number before opening.
• Compare the supplied caliper with the removed unit, including mounting points and hydraulic connection.
• Inspect the brake disc for scoring, thickness and runout.
• Inspect pads and replace them if required.
• Use the correct brake fluid specified for the motorcycle.
• Use new sealing washers where required by the service procedure.
• Bleed the rear brake system correctly after hydraulic work.
• Use only the model-specific Royal Enfield tightening specifications; no torque value is guessed in this listing.
• Check for leaks and correct pedal feel before moving the motorcycle.
• Verify proper wheel rotation and that the brake releases fully.
• Brake work should be carried out by a competent motorcycle technician.

Not for Modern J-Series / 450 / 650 Models by Assumption

Do not order 594054/B for Meteor 350, Hunter 350, Classic 350 Reborn, New Bullet 350 J-Series, Himalayan 450, Guerrilla 450, Super Meteor 650, Shotgun 650, Classic 650, Bear 650, Interceptor 650 or Continental GT 650 unless that motorcycle’s exact EPC specifically calls for this part number.

Shared brand, engine capacity or visual similarity does not prove brake-caliper interchangeability.

Ordering & Return Note

Please verify 594054/B, motorcycle model, model year, rear-brake type, ABS/non-ABS arrangement where relevant, caliper shape and hydraulic connection before opening or installing the part.

Correctly supplied parts are not returnable for wrong selection, wrong diagnosis, mechanic recommendation, fitment mismatch or change of mind. Wrong, damaged or missing-item claims should be reported with the required complete unboxing video within 24 hours of delivery.

Frequently Asked Questions

Q: What is Royal Enfield 594054?
594054 is the base reference for a genuine Royal Enfield rear brake caliper family. The older exact part number is 594054/A, and current genuine-parts data shows 594054/B as its replacement.

Q: What is the current part number?
The current replacement reference shown by Royal Enfield genuine-parts databases is 594054/B.

Q: Does it fit Thunderbird 350?
Yes. The original Thunderbird 350 factory parts catalogue lists 594054/A as the rear caliper assembly, quantity one. Current data replaces /A with /B.

Q: Does it fit Thunderbird 500?
Yes. The original Thunderbird 500 parts catalogue lists the same 594054/A rear caliper, quantity one, with current replacement 594054/B.

Q: Does it fit Classic 500?
Current genuine-parts assignment data includes multiple Classic 500 variants such as Gunmetal Grey, Pegasus, Euro 4, Redditch and Stealth Black. Confirm exact VIN and rear-brake configuration before ordering.

Q: Does it fit Classic 350 or Bullet 500?
Some Indian specialist fitment databases cross-list 594054/A for specific Classic 350 UCE rear-disc and Bullet 500 BS4 applications. Verify the exact motorcycle EPC and old caliper before ordering because this broader fitment is configuration-sensitive.

Q: Is the rear master cylinder included?
No. The rear master cylinder is a separate component in the hydraulic brake circuit.

Q: Is this the brake-pad kit?
No. This is the complete rear caliper assembly. 594698/A is the rear-caliper brake-pad kit in the original Thunderbird catalogue.

Q: Will it fit a drum-brake motorcycle?
No. A rear brake caliper is used with a hydraulic rear-disc brake system.

Buyer Search Terms

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