MPA Electrical M1678 Brake Master Cylinder

Brake Master Cylinder for Jeep CJ5 and CJ7

Restore consistent brake pedal response with this remanufactured brake master cylinder from MPA Electrical. Built for 1977-1978 Jeep CJ5 and 1977-1978 Jeep CJ7 applications with front disc brakes, this standard replacement uses a cast iron body, integral reservoir, and a 1.063-inch bore for OE-style hydraulic performance.

MPA Electrical remanufactured brake master cylinders are tested against OE specifications using proprietary processes and strict inspection protocols. Part number M1678 is a direct-fit hydraulic replacement for Jeep CJ5 and Jeep CJ7 brake service where dependable fluid pressure and pedal feel matter.

Key Features

• Fits 1977-1978 Jeep CJ5, reman with front disc brakes
• Fits 1977-1978 Jeep CJ7, reman with front disc brakes
• Remanufactured standard replacement brake master cylinder
• Cast iron construction with integral reservoir
• 1.063-inch master cylinder bore diameter
• Includes master cylinder cap
• Uses DOT 3 brake fluid
• Interchanges with part number 4796476

Product Details

Part number M1678 is engineered for brake hydraulic restoration on Jeep CJ5 and Jeep CJ7 models equipped with front disc brakes. The integral reservoir design, two mounting holes, and standard replacement grade support a straightforward master cylinder replacement for vehicles that need renewed hydraulic pressure and more consistent braking response. This unit is remanufactured and tested to OE specifications before release.

MPA Electrical’s reman with front disc brakes product line focuses on remanufactured hydraulic components for specific brake configurations. For this application, M1678 is built around the correct bore size and cast iron housing needed for reliable brake system operation in classic Jeep service.

What It Helps Fix

• Low or inconsistent brake pedal feel
• Internal master cylinder leakage
• Brake fluid loss at the hydraulic unit
• Reduced braking performance after wear or corrosion
• Brake system issues on front disc brake Jeep CJ5 and CJ7 models

Installation Notes

• Verify vehicle configuration before installation: 1977-1978 Jeep CJ5 and CJ7 with front disc brakes.
• Mounting hardware, push rod, seals, and brake booster are not included.
• Bench bleeding the master cylinder before installation helps reduce trapped air in the hydraulic system.
• Use DOT 3 brake fluid only, and inspect brake lines and fittings for wear before filling.
• Confirm the mounting hole spacing and bore specification match the original brake setup.

Quality Assurance

MPA Electrical tests each remanufactured master cylinder against OE specifications using proprietary procedures and strict protocols to help ensure consistent braking performance out of the box. Part number M1678 cross-references 4796476 for the same application.