Modified Mustangs & Fords
Hydraulic Brake Assist System - Just Stop It!
One of the top upgrades we're asked questions about every month is braking. How to get the car to stop better? What brake kit do I use? Should I go four-wheel-disc or just upgrade the front? And so on. One question, however, we don't get asked much is whether an owner should keep the manual brakes or go to power. It seems the majority of the questions center on what to do at the wheels and not so much under the hood. While it's a given that anything you can do to make your brakes more effective and your classic safer on today's roads is good, more often than not we see a dual reservoir manual brake system when a hood is opened. We applaud the dual-reservoir upgrade in the name of safety, however, we feel a lot is being left on the table by not having some sort of assist system backing that master cylinder up.
We've heard from some readers that say they prefer their classic Fords to "feel like a classic when they drive them; with manual steering, manual brakes, roll up windows, and so forth. OK, windows that you have to turn a crank to raise and lower is most likely not going to kill you, but having manual steering and manual brakes can be downright dangerous on the modern high-speed roads many of us travel today. Of course, if you drive your car to a show once a month, that's a big difference than those who are out every weekend hitting cruises, using their classic for errands, or even those that drive their car every day (we love seeing classic Fords/Mustangs on the road as a daily driver!).
For those that really use their classics, having power steering and power brakes puts you on par with those driving around you. So bolting up a power brake vacuum booster is the solution, right? Well, not always. While the vacuum-assist-based brake booster has been around for more than half a century, it's not always the easiest part to package in a cramped engine bay, plus for those of you with the big lumpity-lump cams, you know all too well how poorly vacuum-based brakes work (or doesn't) because you have little-to-no vacuum to speak of with a cam like that. So, if you're running a big-block, a modern modular swap, or have a fairly radical engine, what's the solution? The solution lies in your power steering pump, that's what!
Your power steering system can put upwards of 2,000 psi of fluid pressure to a steering box, rack-and-pinion, or hydraulic ram. Harnessing that fluid pressure to use as a means of brake assist to give a car the feel of vacuum assist brakes, but without the packaging or vacuum hassles, is the job of a hydraulic brake assist unit, commonly referred to as a hydraboost system. First used on heavy trucks and later in GM and Ford vehicles, we bet at least one of your daily drivers has this style of assist system (own a late-model G.T. 500, Terminator Cobra, or a Lincoln Mark VII?). The hydraulic assist unit, in a nutshell, uses the power steering pump's high-pressure fluid to "boost" your brake pedal feel/pressure. The pressurized fluid is then handed off to the steering system and one doesn't affect the other (heavy braking doesn't reduce steering effort, and so on).
Now don't go running out to the salvage yard thinking you'll score one of these assist units on the cheap and have killer power brakes in a weekend. The mounting configuration of these units is tricky at best, and there are many different mounts for all of the manufacturers that use this type of system. Save yourself the headache and do what we did; pick up the phone and discuss your brake system needs with the folks at Hydratech Braking. We were so happy with their system on our Factory Five Cobra replica when we built it that they were our first call when we started figuring out the brake package on project Generation Gap.
Hydratech's assist units are all brand-new (no used garbage that gets a seal kit and a splash of paint), and are designed for the application. The beefy billet aluminum mounting adapters means most kits simply bolt in place of your old vacuum booster or manual master cylinder (on our '68, we did have to drill out a few holes common to a vacuum booster mounting setup). Its trick, threaded booster pushrod means an adjustable-height brake pedal, and the company offers several master cylinder options to boot. With our project's 4.6L Three-Valve modular engine in place, we only had to take one look at our firewall to know it was a Hydratech assist unit or manual brakes, and there's no way we're building a car with this kind of driveline technology with manual brakes.