Hydro-boost power assist was introduced in 1973 by Bendix as an alternative to the vacuum booster. The hydro-boost uses the hydraulic pressure from the power steering system to provide the driver assist in applying the brakes.

Can't Get The Car Stopped? Keep Your Rowdy Cam And Have Brakes, Too, When You Install a Hydroboost Bad brakes is the only reason we would ever consider a cam profile to be too aggressive. Ya see, as the duration and overlap in a cam profile are increased, either because of aggressive lobes with a lot of lift or a narrow lobe-separation angle, the intake valve is opened before the exhaust valve is closed completely. This is the cause of coolness such as a lopey idle and power-enhancing cylinder scavenging and downers such as a low vacuum signal and poor idle. The problem is the power-brake booster needs between 14 and 16 inches of vacuum (depending on whom you ask) to properly assist the brakes.

Most of the cams we like produce 10 or fewer inches of vacuum at idle or at speed when the throttle blades are suddenly closed and you step on the brakes. There are a couple of common fixes for cars that don’t build vacuum-an electric or beltdriven vacuum pump (like on a diesel truck) or a hydroboost. While the electric pumps are functional, they are noisy and take up a lot of space under the hood. The hydroboost is considered the better fix. A hydroboost uses the power steering pump to produce the pressure needed to operate the braking system.

Fluid flows from the pump to the hydroboost, then to the gearbox or steering rack, and finally the low pressure fluid is returned to the pump. The hydroboost is designed to use the high-pressure fluid under braking conditions.

Otherwise, the pressure is simply bypassed back through the steering system. The Power Brake Service hydroboost we used has the capability of producing 2000 psi, much more than a typical stock vacuum-assist booster can provide. Your hub for horsepower Get first access to hit shows like Roadkill and Dirt Every Day Join free for 14 days now Another benefit of the hydroboost setup is the reserve tank. In the event the engine stalls, the hydroboost unit will provide 60 to 75 percent of the total braking force to the brakes on the first stab of the pedal, then 30 to 40 percent power if the pedal is released and applied again, and another 10 to 20 percent for another application. After that, the reserve is depleted and the system will be in manual mode.

This is a safety net that even stock vacuum boosters cannot provide.

I started with the Hydratech Hydroboost kit which came complete with everything needed for the basic installation. After reading many many threads about this install, I discovered a modification which runs the low pressure return line direct to the Power Steering Pump.

This eliminates a 'T' fitting in the basic kit and prevents any fluid feedback to the HB unit. Parts for that mod were Tallon Hydraulics part# 8203 (5/16-24 O-ring male to -6AN male), 2-Russell 613161 90* -6AN hose ends, Russell 670850 -6AN Fuel Cell Bulkhead fitting, Tallon Hydraulics part# 1451 2pack of 3 Hole Hose Clamp Separators and Russell Stainless Steel braided low pressure hose. First drain the PS pump reservoir, remove old PS hoses from pump and steering box Then remove old master cylinder brake pedal rod from the brake pedal Disconnect the front and rear brake lines and remove the old master cylinder I made a new gasket to fit between the new HB unit and the firewall, I used Felpro# 3157 rubber fiber gasket material from NAPA Auto Parts.

Then I installed the HB unit. Boeing 737 cbt download. Before installing the Wilwood master cylinder, install the two high pressure lines and the low pressure return line. Installation of these hoses is nearly impossible if you install the master cylinder first (ask me how I know). Remove the preinstalled brass 90* fitting for the low pressure return port from the HB unit, and replace with the THI 5/16'-24 O-ring male to -6AN male fitting on the HB unit. Be sure to torque ONLY to 10 ft. As the threads for this fitting can strip very easily.