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Hydroboost by Hydratech
Hydroboost by Hydratech

List Price: $1,400.00
Our Price: $1,099.95
You save $300.05!

Product Code: 3786

Select Brake Configuration

How Much Body Lift?

Choose Engine

Do you have Short or Tall Valvecovers?

Carb or EFI?

Air cleaner points towards?

Select Firewall Modification

Select Prop Valve

Select Adjustable Prop Valve

Do you need MC to PV lines?

Choose your Front Disc Setup

Choose your Rear Brake Setup

Choose your E-Brake



Need the BEST stopping power? Did you upgrade your tire size and now your brakes don't perform as good as they used too? Does your new engine have a big, vacuum-robbing cam that makes it feel like you're back to manual brakes?

Introducing the next level of braking performance: The James Duff/Hydratech Hydroboost Kit! With its primary components built by the best in the industry, Hydratech Braking Systems.

Our hydroboost kit, when combined with our supplied master cylinder, makes for a *smooth install and your Bronco will *stop on a dime.

Check out the install video here: (coming January 2020)
James Duff offers the best performing brake systems in the industry. We don't just say that we can PROVE it.

We care about supplying the best parts for your Bronco. But, we care just as much about your safety and the safety of others around you while you're enjoying your Bronco. That is why we spent the time and tested the products available. We will only sell what WE have tested and determined to provide the best, controlled stopping power.


What sets James Duff apart from the rest? Let's take a competitor's product that "appears" the same as ours. Let's dive deeper into the James Duff/Hydratech Hydroboost kit and review what sets it apart:

Genuine Hydratech Hydroboost firewall mounting plates are machined out of a solid chunk of billet aluminum. They are not cast aluminum (with "machining") like other systems currently sold. Why does this matter? Cast aluminum, although great for making items such as custom wheels, is prone to cracking when subjected. When you step on your brake pedal, you're exerting leveraged force onto those mounting plates. If they crack, performance could be compromised. If they break, your Bronco's brakes could fail. This would be a serious problem in a panic situation.

With the most common engine and body lift configurations, there is no modification necessary to the firewall. That's right, no template to make and no hole to cut! Ours is the first kit available from a Bronco vendor that requires absolutely no firewall modification ( for the majority of installations)! This is an additional benefit to the DUFF/Hydratech kit because that mod is not easy for everyone to do (and easy for some to do wrong).

The brand new, Bosch Hydroboost unit is thoroughly inspected, then modified specifically for the mounting angle needed in a Bronco. Next, it is pressure-tested, cleaned and then painted with two-stage automotive grade paint. Other vendors offer new units too, but do they ensure they are perfect before you get it? It's one thing for it to be new, it's another for it to be RIGHT!

Only Aeroquip and Eaton hoses and fittings are used. Why does this matter? Import lines and fittings are not subjected to the same testing processes as our quality components. This can lead to leaks in a high pressure, heat and vibration prone environment like that found under the hood of your Bronco. It's not a matter of IF there will be an issue, it's a matter of WHEN. This is another area where other Bronco vendors cut corners to reduce their costs. Not only is this cost "savings" not passed on to you, but the choice to use the inferior components also is actually not allowed by Hydratech. The primary reason is not just to use a more expensive component. Rather, it is because they KNOW that Aeroquip and Eaton products exceed the most exacting quality standards. In fact, Hydratech has the same testing equipment at its own facility as do Aeroquip and Eaton. Just another step in ensuring that their product is the best one out there.

Always sold with the correct master cylinder. Why is this so important? Did you know that if you use the wrong master cylinder when you install your system, you run the risk of destroying the hydroboost unit? With James Duff looking out for you, there is no guessing and no risk of the wrong choice destroying your brand new Hydroboost unit. We have taken the extra time, and expense, to "match" you and your Hydroboost system with the best master cylinder for your needs. In the end, not only can you proceed without fear, but you can rest assured that you will "Whoa!" your Bronco in the shortest distance, with the most control, possible.


Hydroboost is a high performance hydraulic (fluid) brake assist booster. It is a more powerful alternative to a vacuum (air) assist type booster. This type of brake assist unit plumbs into your power steering pump and uses the hydraulic pressure from the power steering system (instead of engine vacuum) to provide a variable brake pedal assist. That's correct, whereas vacuum assist is limited and continuous; Hydroboost is variable. The harder (or faster) that you push the pedal, the more assistance provided.

But, the truth is, not everyone needs Hydroboost. That's right, we aren't here to brainwash you into believing you can't live without this. If your engine provides sufficient vacuum (18" or more at warm idle), your tire/wheel combo is mild to moderate, and you rarely tow or do "hard wheeling", our "regular" power brake systems should do an outstanding job of exceeding your needs.

So, when should you consider Hydroboost?
  • When needing your brakes to react more quickly in a panic stop
  • If you prefer a "lighter" feeling brake pedal
  • If you want more control during a panic stop
  • If you are considering or are running 35" or bigger tires
  • If you have installed a high-performance motor or "wilder" camshaft and now have less than 18 inches of vacuum at warm idle
  • If you enjoy or plan to do off-roading down steep, technical trails or obstacles where deep gearing can overpower manual or vacuum-assisted brakes
When should you NOT consider installing hydroboost?
If your brakes are NOT already working properly
Adding hydroboost is like adding an amplifier to your sound system. Whatever it is doing now it will do even better (or worse) when adding hydroboost. For example, if your back brakes lock up when you slam the brake pedal, hydroboost will just make them lock up sooner with less pedal effort. This gives your Bronco more ability at higher speeds to behave poorly and possibly put you in the ditch (or worse). (Let James Duff's knowledgeable Senior Techs help get your Bronco's brake system working properly BEFORE you spend more money and time throwing parts at it and potentially making it even less safe.)

Drum front brakes
We do not recommend Hydroboost on your Bronco's with front drum brakes. We have found that excessive grabbing and left to right front brake pull occurs with the use of this system. In fact, we would not even offer a Hydroboost upgrade with this setup.

If you have 32" tall tires or smaller
This isn't a hard and fast rule, but honestly, we have several other braking options and kits that work great all the way up to a 35" tire. In these cases it doesn't require a hydroboost unit to stop quickly and predictably. Let our technicians help recommend which braking system is right for your intended use.

  • With the limited exception of some front calipers, all of our components are 100% BRAND NEW! All brake assist systems are carefully prepared by experienced, skilled craftsmen here in TN.
  • All items produced are the highest quality available and extensively inspected before shipment.
  • James Duff is the first, and only, Bronco vendor to offer a Hydroboost kit that requires no modifications to the firewall.
  • Engineered specifically to fit, function and operate in your 66-77 Bronco.
  • CNC machined T6061 billet ALCOA aluminum mounting plates.
  • Brand new, current production year, genuine Bosch OEM quality brake assist units.
  • Brake unit castings professionally coated in two-stage, industrial black (with "show quality" systems as an option).
  • Factory dyno-tested for precise operation.
  • Install using common hand tools - check out the video here (video coming January 2020)
  • Genuine Aeroquip braided stainless TFE line sets.
  • Genuine Eaton reusable/rebuildable hose ends.
  • All small parts required for installation included.
  • Clear step by step easy to read and understand install instructions as well as an install video here:
  • The best sales and tech support available by phone and email - check out our install video first here:
  • 1 year limited manufacturer's warranty against defects in materials and workmanship.


  • Genuine Hydratech-spec'd Bosch Hydroboost unit
  • 2 high-pressure stainless steel braided Aeroquip lines
  • 1 Extreme Duty Parker hybrid rubber return line
  • Eaton fittings
  • Hose clamps
  • Semi-Universal power steering pump fitting adapter kit
  • New brake pedal rod and adapter


Our no-mod hydroboost kit is our most popular upgrade and can be selected above in our drop-down options. This system requires zero modifications to the firewall of your 66-77 Bronco. *EXCEPTIONS AND EXCLUSIONS APPLY
The new hydroboost kit also comes standard with a new master cylinder. This is a great time to upgrade your brake lines from the master to your proportioning valve with James Duff's brake line kit, 3742.
Add a combination valve (3746 or 3747) with or without bracket (3738) and/or an adjustable proportioning valve (with bracket included). Not sure what you need? check out this video here (not available yet)
Add an adjustable proportioning valve in line to your existing proportioning valve (3745)
Need to upgrade your power steering pump or entire power steering system? Click here.
Don't have front disc brakes yet? Check out these options that pair nicely with hydroboost 3730, 3777, 3778
Looking for a rear disc brake kit? We've got premium and budget-friendly options here: BRB 3716,17,18 & 19
Want to press the easy button? Looking for the whole shebang? Check out our Monster Disc Brake System options here for your Bronco...front & rear (Coming online first quarter 2020, in the meantime, you can call our sales team to order.)


Q. Why Hydroboost?
A. Anytime you add a lift+larger tires, run an engine with a low vacuum or want the best response out of your braking system, you will benefit from hydroboost.

Q. Why choose Duff's?
A. All American assembled out of the best quality parts that are proven by Duff's to work the best. Customer service and tech support second to none.

Q. Can I use hydroboost with front axle drums?
A. NO - we highly recommend not combining hydroboost with front drums for safety reasons.

Q. What steering pumps and boxes does this kit work with?
A. Bronco, Explorer and Saginaw pumps as well as stock and aftermarket power steering gearboxes. Keep in mind, if any of your components are old, tired and/or worn out, this will be a good time to freshen them up or replace them. Link for more info here.

Q. Do I need to use an adjustable proportioning valve with hydroboost?
A. It varies depending on how your Bronco is built. Check out this video to learn more about proportioning valves.

Q. What type of fluid should I use with my power steering system. I have been told the automatic transmission fluid (ATF) can be used?
A. OEM fluids from the dealer are the absolute best. You can use any type of commercially available power steering fluid that meets the specifications of your vehicle. You should not use any type of ATF as it may foam excessively when it gets warm. Please also be very careful not to accidentally use the wrong fluid in either the brake or the power steering systems as substantial systems damages will occur!

Q. Can I mix steering fluid?
A. We don't recommend this but if you drain the system from the lowest point and add new fluid it won't hurt if a little old mixes with new.

Q. Can I damage the hydroboost unit by installing it improperly?
A. YES! If you allow the push rod inside the hydroboost unit to move forward or back before 100% installed with the correct master cylinder bolted in place you will destroy the unit and void its warranty.

Q. What all do I need to do the install?
A. Check out this video here (Video coming January 2020)

Q. Is there a troubleshooting guide available if I run into a problem or issue?
A. Yes, but we have found that 99% of the problems or issues that arise are due to installation errors, e.g.: lack of research, being impatient, using the wrong tools and not paying attention to details. Click here for the troubleshooting guide.

Want to learn more and view more info? check out this link...


There are numerous different ways you can build and accessorize your 66-77 Bronco. Above, you will see we give A LOT of information. Additionally, we ask you several questions to ensure we send you what you want. Of equal importance, we want to send what works best for your Bronco.

Warning, please be certain of your selections above...or call us for guidance. If we ship the parts and components that you select, returning for any reason will be your responsibility and at your cost. If you select the wrong parts and you attempt to (or do) install them, we will not authorize or accept a return. Parts from these systems are ONLY returnable if they are unopened, in the original packaging. These systems are incredibly expensive to build. Be certain of your needs and understand this policy. It is unlikely to be deviated from. If you choose to return parts or components that do not meet these explicit requirements, understand that we will likely refuse to accept the return. We will not refund any of your purchase price, shipping costs, or other expenses. Additionally, you will be responsible for return shipping charges if your return is refused. You are required to ship any returns with insurance sufficient to cover all costs in the event of a total loss in transit. We withhold the right to reduce your refund or only give you partial credit in cases where shipping damage or shortages occur. At your option, you can elect to have damaged or shorted shipments returned to you at your cost. Please be careful, take your time, and be sure of your decision-making process. This may be the best upgrade you ever perform on your Bronco. Thank you for choosing James Duff.

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