Hydroboost Brake Conversions 1963-1966

This is one of the best brake upgrades you can do to an FSJ! The stock vacuum booster (either single or double diaphragm) leaves a lot to be desired. This Hydroboost System uses power steering fluid to energize your system, completely replacing your Vacuum Booster. These kits come stock on New Heavy Duty and Diesel Trucks for their amazing stopping power!

This unit will bolt straight to bolt holes on your firewall. This hydroboost unit will ship with the firewall mounting bolts and the nuts for the MC bolts. The accumulator may be a different color (shown in silver).

This hydroboost is a short-input style that requires a dimple-input master cylinder.  Long-input master cylinders are not compatible.

**Note: if you are converting from manual brakes, the manual brake pedal will sit higher with the hydroboost.  In order to have a lower pedal, you will need to swap to a power brake pedal as they have a different ratio which locates them down a bit.  If you plan on doing this, you will need to order the hydroboost with the brake pedal rod side on the driver's side (left side) of the pedal in the pull down menu.

Once ordered, contact us with your order number and we will email instructions / guides to help with the install.

**NOTE: DO NOT, under ANY circumstances, depress the brake pedal without the master cylinder fully connected / installed / seated!  If you do, this will cause the pushrod, spring, baffle and retainer to shoot out under incredible force and at incredible distances.  This has the potential to seriously injure bystanders and cause major damage.  It can also damage / ruin the hydroboost.  

**FLUID TYPE: Never use ATF in the power steering system or with a hydroboost.  These systems must use PS Fluid ONLY!  ATF fluid does not have the correct viscocity or anti-foaming agents, and will void the warranty.  We sell the correct fluid HERE!!!