This is a complete bolt in kit that uses a modern hydroboost unit and dual circuit master cylinder mounted to the firewall using the bolt holes for the factory air box. Hydroboost is extremely powerful, even more so than most any vacuum booster. This will give power brakes on your 1954-1956 Cadillac like you have never experienced before. You will be able to lock up brand new tires on a summer day with a fully loaded car if you want! The pedal feel will be fairly aggressive but still controllable. This can NOT be used with front drums. You will need at least a front disc conversion, and ideally a rear disc conversion too.


The hydroboost requires plumbing in to your power steering pump. The plumbing is not included. There are three ports on top of the hydro unit- a 6AN port to connect to the pump, a 6AN port to connect to steering box high pressure, and a 3/8 hose barb for a standard rubber return hose. The 6an and barb fittings are included, you need to supply everything else.


This kit includes a new brake pedal that swings from a higher location (looks like it could be original to the untrained eye too).

This kit can be used with disc/ drum or disc/ disc. Let me know what brakes you have at check out and I will send the correct proportioning valve. As an option, you can also get an adjustable proportioning valve. This is not necessary but could be good if you are planning on swapping brake types.


The master cylinder has a 1.125" bore which is significantly larger than factory. Even with large multi piston calipers, your pedal won't reach the floor.

Installation is fairly straightforward- no cutting required, this kit doesn't involve anything permanent that can't be undone in a few hours! You have to remove the driver side air box, vent door, master cylinder, master cylinder mounting plate, and then this kit bolts in. The rear brake line will require some cutting and flaring. Brake lines are included and pre-bent. Installation time is about 4 to 6 hours.

Please know that this kit requires doing away with the driver side heater. Perhaps you can cut a hole through this firewall air box but this is not something that I have had the occasion to test so I don't have any instructions on this.

Brake Lines: Two brake lines are included. One goes from rear proportioning valve to the original junction block mounted to the driver side frame rail in place of the line that originally lead to the front brakes (no cutting or flaring needed). The other brake line feeds the rear brackets and you will need to cut and flare your original lines to accommodate this. The brake light switch is unaffected.

This kit fits all models of 1954, 1955 and 1956 Cadillacs.

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.

Chrome master cylinder is available for an extra $30

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.

Included Parts
Firewall plate
Brake pedal bracket
Brake pedal
Rubber pad for brake pedal
Hydroboost unit with 6an adapter fittings
Master cylinder
Proportioning valve with bracket and lines
Hardware for entire installation
2 brake lines to plumb in
Instructions