GMA Engineering 5/8 Bore Rear Master Cylinder Rebuild Kit for Kelsey Hayes and Wagner Style

GMA Engineering 5/8 Bore Rear Master Cylinder Rebuild Kit for Kelsey Hayes and Wagner Style

A worn master cylinder does not have to mean pulling the unit and sourcing a replacement. This GMA rebuild kit restores the hydraulic integrity of GMA’s 5/8″ bore rear master cylinders back to proper operating condition — bringing back the firm, predictable pedal response that a correctly functioning vintage brake system demands.

Key Features

• Purpose-built for GMA Engineering 5/8″ bore rear master cylinders — covers both the Kelsey Hayes inline (GMA-MC1K) and Wagner offset (GMA-MC1W) styles
• Restores full hydraulic function and seal integrity without full unit replacement
• Verify the top cover dimensions match your GMA cylinder before ordering

Technical Specifications

• Bore Size: 5/8″
• Compatible Brand: GMA Engineering
• Compatible Styles: Kelsey Hayes inline (GMA-MC1K), Wagner offset (GMA-MC1W)
• Top Cover Length: 3-1/8″ (3.125″)
• Top Cover Width: 1-7/16″ (1.4375″)
• Application: Rear master cylinder rebuild

Fitment Notes

• Designed specifically for GMA Engineering 5/8″ bore rear master cylinders — not a universal rebuild kit
• Top cover must measure 3-1/8″ (3.125″) x 1-7/16″ (1.4375″) — verify against your cylinder before ordering
• Not compatible with 3/4″ bore master cylinders