Radium 20-0843 Stainless Master Cylinder Brace for 1989-1997 Mazda MX-5 LHD ABS

Vehicle Fitment

• 1989-1997 Mazda MX-5 Miata (LHD, with ABS)

Fitment Notes

• Left-hand drive (LHD) models with ABS only - not compatible with RHD chassis or non-ABS models
• 1998-2005 (NB) Mazda MX-5 uses a separate, non-ABS-specific brace (Radium 20-0844), sold individually
• Compatible with OEM or aftermarket strut tower braces
• No cutting, drilling, or permanent modification required

Features

• Reduces brake master cylinder deflection by 90%, measured with a dial indicator before and after installation
• Eliminates firewall flex so more of the brake pedal's mechanical input goes directly into hydraulic line pressure
• Delivers a firmer pedal feel and more responsive braking under hard use
• One-piece stainless steel construction with a powder coat finish prevents secondary flexing
• Large-diameter aluminum-head adjustment screw is positioned to avoid damaging the master cylinder housing
• Includes stainless steel jam nuts to prevent preload slippage over time
• Longer upper strut studs are included to compensate for the brace's added thickness
• Stainless steel shims included for the passenger-side strut to help level the strut tower bar, if equipped
• Quick, straightforward bolt-in installation

Specifications

• Material: Stainless Steel
• Finish: Powder Coated
• Construction: One-Piece Design
• Mounting Hardware: M8, torqued to 30 lb-ft (40 Nm)
• Measured Deflection Reduction: 90%

Included Components

• 1x Master Cylinder Brace
• 1x Set Longer Upper Strut Studs
• 1x Set Stainless Steel Jam Nuts
• 1x Set Stainless Steel Shims (Passenger-Side Strut)

Product Description

The Radium 20-0843 is a bolt-in master cylinder brace built for the 1989-1997 (NA) Mazda MX-5 Miata in left-hand drive, ABS-equipped configuration. It installs at the strut tower to address a common weak point on this chassis: firewall flex under hard braking, which absorbs pedal input that should be going into hydraulic line pressure instead.

Measured with a dial indicator, the brace reduces brake master cylinder deflection by 90%, translating into a noticeably firmer pedal and more consistent, responsive braking. Its one-piece stainless steel design with a powder coat finish resists the secondary flexing that multi-piece braces can suffer from, and a large-diameter aluminum-head adjustment screw is positioned to preload the brace without risking damage to the master cylinder housing itself.

Installation is straightforward - no cutting, drilling, or permanent modification is required, and the kit includes longer upper strut studs to account for the brace's added thickness, stainless steel jam nuts to lock in preload, and shims for the passenger-side strut to help keep an OEM or aftermarket strut tower bar level if one is installed.