State of the art Corvette stuff is cool. State of the art Corvette stuff for older Vettes is even better. And state of the art stuff for vintage Vettes that is more advanced than what comes off the Bowling Green assembly line on brand new Corvettes is WAY cool!
For the most part, C5s are great examples of the best of contemporary high-performance engineering. They are, however, Chevrolets, which means that mass-production, high-volume purchasing, and in some instances using the least expensive component that will do the job is a fact of life. That doesn't mean that a particular part or system is bad; it just means that a more advanced but more expensive setup is passed over to save a few bucks (or even pennies) per-unit.
Braking systems have advanced drastically since the advent of disc brakes on Corvettes, starting with the 1965 models. With the exception of just 316 '65s that were ordered with RPO J61, the drum brake substitution credit, every Vette since has come with four-wheel disc brakes, and power assist (J50) increased in popularity (measured as a percentage of out of total annual production) every year from 1965 until part way through the 1976 model run, when power assisted brakes and steering became standard equipment. Each and every '65-76 with RPO J50, and every Corvette since has utilized a vacuum-powered booster to lessen the effort needed to operate the brakes.
Here's a sight familiar to...
Here's a sight familiar to anyone who owns (or has owned) a '68-82 Corvette with power brakes-the bulky, stamped sheetmetal vacuum brake booster which we're going to replace with Hydratech Braking Systems' new hydro-boost hydraulic power brake booster system. Everything, with exception of a bottle or two or fresh power steering fluid and possibly some ibuprofen for your back, after you're done crawling under the dash twice) is included, right down to the braided stainless steel high-pressure lines that are prefitted with billet line clamps.
Overall, vacuum power brake boosters work fine. But vacuum assist does have its shortcomings-boosters are fairly bulky and cumbersome, and the feel (response and action) is not always consistent. Plus, if an older Corvette is equipped with both power assist brakes and has a "hot" (long duration) cam, the brake assist can vary from semi-marginal to damn near non-existent because a lumpy, lotsa duration cam does NOT produce much engine vacuum. Vacuum canisters are a common "band-aid" fix for this problem.
Hydraulic brake assist, or, as it's more commonly called, hydro-boost, is not new. It has a lot of benefits and very few drawbacks; the drawbacks being that power steering is a necessity (that could be an issue in early Sharks, when power assisted steering was not especially commonplace), and cost. A stamped sheetmetal booster and a few rubber vacuum lines and fittings are a lot cheaper to produce than a hydraulic booster unit and some high-pressure hoses.
Hydro-boost brake systems are a mystery to many people. Some associate hydraulic assist for brakes as something that belongs in big rig trucks; not the sort of thing one would install on one's Corvette. On the other hand, hydro-boost, which was originally developed by Robert Bosch GmbH, the highly regarded German automotive and industrial technology and engineering firm, is used on some very high-end European sports, ultra-performance, and luxury cars. Ford has been using a hydro-boost setup on all Mustangs-including the fearsome '00 R-model Cobra-since 1996, and on several of their upscale products.
 The vacuum supply hose running...  The vacuum supply hose running from the intake manifold to the brake booster is removed next and the fitting is capped with the 3/4-inch vacuum cap that's part of the kit. Then comes the fun part-under-dash diving. While under the dash, locate and disconnect the brake light switch electrical connector. Find and remove the pin and clip that join the brake pedal and the rod that feeds from the pedal through the firewall and into the brake booster. Then, disconnect the four nuts that attach the brake booster. |  After extricating himself...  After extricating himself from beneath the dash, Loy carefully pulls (you might need to pry) the booster from the firewall and removes it from the car. |  Loy figured it would be easier...  Loy figured it would be easier to pre-set the distance of the clevis to the firewall, based on its position on the old vacuum booster (and allowing for Hydratech's recommended 3/4-inch lower pedal height) with the hydro-boost unit on a workbench rather than while crawling in and out from under the dash and groping around almost blindly. |