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This is a complete bolt in kit for 1957 and 1958 Cadillacs. This kit uses a modern power booster and dual circuit master cylinder mounted to the firewall using the bolt holes for the factory air box. It includes a new brake pedal that swings from a different location (looks like it could be original too). A modern GM booster and master cylinder give a significantly improved braking feel and power while adding safety through the dual circuit system. 
This can be used with factory drums, disc/ drum or disc/ disc. Let me know what brakes you have at check out and I will send the correct proportioning valve. 


This kit deletes the driver side heater function. I have had a couple customers route their own ducting by cutting a hole in this new firewall plate and routing smaller diameter ducting, but that is not something I have attempted so I don't have specific instructions on how to accomplish that.

It will have the pedal feel of a modern car- minimal effort required with a positive and firm feel. No more soft or sloppy pedal! 
Installation is fairly straightforward- likely no cutting required, this kit doesn't involve anything permanent that can't be undone in a couple hours! You have to remove the driver side air box, vent door, master cylinder, master cylinder mounting plate, and then this kit bolts in. Brake lines are included and pre-bent but the rear line will require you to splice in to your original system. Installation time is about 4 hours. 
This kit comes with everything including proportioning valve, brake lines, and hardware! All you need is brake fluid and a port on your intake to plug into vacuum. 
Also, you will have more room in the valve cover area that the original air box. so it clears all original engines just fine, and will provide additional clearance for vehicles with a swapped engine. 
The firewall box has water drain spouts and new drain hose is included. water will be able to drain out from the windshield area just as factory. 
What you get: 
  • Firewall box 
  • Brake pedal bracket, goes through air vent hole 
  • Brake pedal W/ Bushings and rubber pad 
  • GM style brake booster
  • GM style master cylinder 
  • All new high quality bolts 
  • 2X 3/16" brake lines- custom cut, bent, and flared
  • Proportioning Valve + metal lines (mounts beneath MC, pictured)  
  • 3/8 Vacuum hose
  • Water drain hose, same style and function as factory 
  • Misc. hardware 
Chrome Parts are available. Brake Booster and Master Cylinder in chrome is +60.
All metal parts are CAD designed, laser cut, formed on a computer controlled press brake, professionally welded, and painted satin black for consistent high quality results.

1957-1958 Cadillac Power Brake Conversion kit Modern Booster Master Cylinder G1

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