RIDEX Rear Left Brake Caliper – MX-5 Mk1 NA 1.8 / Mk2 NB Standard Brakes • 78B0647

RIDEX Rear Left Brake Caliper – 78B0647

Brand-new replacement rear left brake caliper for Mazda MX-5 Mk1 / NA 1.8 and Mk2 / NB / Mk2.5 / NB-FL 1.6 and 1.8 petrol models (1994–2005) equipped with the corresponding standard rear braking system.

RIDEX 78B0647 is a replacement single-piston rear brake caliper incorporating an integrated mechanical parking brake mechanism. Designed for installation on the rear left-hand side of the vehicle, it is suitable for the UK passenger-side rear wheel.

The brake caliper is an essential component of the hydraulic braking system. When the brake pedal is applied, hydraulic pressure moves the caliper piston, pressing the brake pads against the brake disc to generate the friction required to slow the vehicle.

Unlike a front brake caliper, the MX-5 rear brake caliper also incorporates a mechanical parking brake mechanism, allowing the rear brakes to provide a holding function when the handbrake is applied.

Over time, original rear brake calipers can deteriorate through exposure to road salt, moisture, corrosion and repeated braking cycles. Internal piston seals, sliding components and parking brake mechanisms can become worn or damaged, potentially affecting braking performance.

A sticking or seized rear caliper may prevent the brake pads from releasing correctly, leading to excessive brake drag, uneven pad wear, increased disc temperatures and premature deterioration of braking components.

Brake caliper deterioration can also cause hydraulic fluid leaks, uneven braking force, a binding wheel or poor parking brake operation.

RIDEX 78B0647 provides a complete replacement caliper body featuring a 32mm hydraulic piston and an integrated parking brake mechanism.

The caliper is manufactured from cast iron and is designed for the corresponding standard rear braking system using 251mm nominal solid rear brake discs with a thickness of 9mm.

The 124mm mounting bore spacing corresponds to the relevant rear caliper mounting arrangement, allowing installation using the compatible original brake caliper carrier and associated mounting components.

Unlike remanufactured or reconditioned calipers, this RIDEX replacement is supplied brand new, providing a fresh replacement component for rear brake system repairs and refurbishment.

The caliper is suitable for the Mazda MX-5 Mk1 / NA 1.8 and Mk2 / NB 1.6 and 1.8 models fitted with standard rear brakes, including compatible Mk2.5 / NB-FL variants.

Key Features & Benefits

• Brand-new replacement rear left brake caliper
• Suitable for Mazda MX-5 Mk1 / NA 1.8 and Mk2 / NB 1.6 / 1.8 models
• Compatible with the standard rear braking system
• Rear left-hand installation – UK passenger side
• Single-piston hydraulic brake caliper
• 32mm caliper piston diameter
• Integrated mechanical parking brake mechanism
• Durable cast-iron construction
• Designed for 251mm nominal solid rear brake discs
• Suitable for 9mm-thick rear brake discs
• 124mm mounting bore spacing
• Suitable for replacing seized, leaking or damaged original rear calipers
• Brand-new construction – not remanufactured or reconditioned

Product Specifications

• Product type: Rear brake caliper
• Fitting position: Rear axle, left-hand side
• UK vehicle position: Rear passenger side
• Brake system: NBK
• Caliper design: Single-piston brake caliper
• Parking brake: Integrated mechanical parking brake mechanism
• Piston diameter: 32mm
• Material: Cast iron
• Compatible brake disc diameter: 251mm nominal
• Compatible brake disc thickness: 9mm
• Mounting bore spacing: 124mm
• Mounting carrier: Not included
• Vehicle compatibility: Mazda MX-5 NA 1.8 and NB / NB-FL 1.6 / 1.8 with standard rear brakes
• Quantity supplied: 1 rear left brake caliper
• Condition: Brand new
• Manufacturer: RIDEX
• Manufacturer part number: 78B0647
• EAN: 4059191515110

Fitment Advice: Suitable for the rear left-hand side of Mazda MX-5 Mk1 / NA 1.8 and selected Mk2 / NB and Mk2.5 / NB-FL 1.6 and 1.8 models fitted with the standard rear braking system. Early Mk1 / NA 1.6 models and Mk2.5 Sport variants equipped with larger rear brakes use different braking components.

Important: This caliper is designed for the rear left-hand side only and is supplied without the mounting carrier. The corresponding RIDEX rear right-hand caliper is part number 78B0288.

Signs of a Failing Rear Brake Caliper: A sticking or seized brake piston, excessive brake drag, uneven rear brake pad wear, brake fluid leakage, unusual braking temperatures, reduced braking performance, a pulling sensation during braking or poor parking brake operation.

Other Items to Consider: Rear brake discs, rear brake pads, brake caliper carrier and slider components, flexible brake hoses, brake fluid, brake pad fitting hardware and replacement brake mounting fasteners.

Useful Tools / Consumables: Vehicle lifting equipment, axle stands, socket and spanner set, brake hose tools, brake fluid collection equipment, calibrated torque wrench, brake bleeding equipment, suitable brake cleaner and approved brake assembly lubricant.

Difficulty Guide: Moderate to Advanced. Replacement involves disconnecting the hydraulic brake system, transferring the appropriate mounting components, reconnecting the parking brake mechanism and bleeding the rear brakes. Professional installation is recommended.

Why RIDEX? RIDEX supplies aftermarket braking and vehicle maintenance components designed for reliable replacement of worn or damaged original parts. The 78B0647 offers a brand-new replacement rear brake caliper for compatible Mazda MX-5 standard braking systems, providing a practical alternative to rebuilding an ageing original caliper.

What's in the Box: 1x RIDEX 78B0647 Rear Left Brake Caliper with integrated parking brake mechanism. Supplied without the caliper mounting carrier.

Installation / Service Notes: Follow the applicable Mazda rear brake caliper replacement procedure. Safely raise and support the vehicle before removing the rear left wheel. Inspect the existing caliper, brake hose, brake pads, brake disc, mounting carrier and parking brake cable for damage or deterioration. Release the parking brake and disconnect the parking brake cable from the original caliper as required. Disconnect the hydraulic brake hose using suitable tools and collect any escaping brake fluid. Remove the original caliper, retaining the compatible mounting carrier and other reusable components. Clean and inspect the mounting areas before fitting the replacement RIDEX caliper. Install the new caliper with the appropriate mounting hardware and tighten all fasteners to the specified Mazda torque settings. Reconnect the hydraulic brake hose using the correct sealing arrangement and refit the parking brake cable. Install compatible rear brake pads and ensure that the caliper sliding mechanism operates correctly. Fill and bleed the hydraulic braking system using brake fluid meeting Mazda's specified requirements. Adjust the rear brake and parking brake mechanisms in accordance with the Mazda workshop procedure. Before moving the vehicle, restore normal brake pedal travel and inspect all hydraulic connections for leaks. Confirm correct brake release, parking brake operation and wheel rotation, then carry out a controlled road test and final inspection.