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Please know that there is an estimated 3 week lead time on the brake pedals used in these kits. If it is helpful, I can send everything but the pedal when you order, and the pedal when I am able. Otherwise I can send the entire kit when all parts are ready. Sorry for the inconvenience.


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 modern vacuum booster. This will give power brakes on your 1956 Buick 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). Also included is a new sheet metal piece that bolts in below the steering column. This is required as a result of interference between the new brake pedal and the original brake pedal mounting tabs.
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. Brake lines are included and pre-bent. Installation time is about 4 to 6 hours.
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 goes from the front of the new proportioning valve to the factory T junction block located near the front driver side wheel and feeds the front brakes (again no cutting or flaring needed). Finally, the brake light switch is relocated from the original master cylinder that is no longer being used to the port on the factory frame mounted junction, where the original master cylinder use to enter. (a proper flare to npt fitting is included).
This kit ONLY fits the larger Roadmaster and Super. This will not fit the Special or Century models.
Your valve cover clearance will increase but the master cylinder will sit very close to your inner fender.
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.
For power steering cars only, the power steering column is held in place by a bracket that attaches to the factory air box. This kit includes a bracket that performs the same job. It works well but is not easy to bolt in. Very doable, but will require someone who is fairly flexible.
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

Steering column bracket

16gauge steel plate to conver floor where OEM booster/master was installed

Hardware for entire installation

2 brake lines to plumb in

Flare adapter fitting to relocate brake light switch


1956 Buick Roadmaster Super Hydroboost Power Brake Conversion

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