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Mixing Brake Parts for the Better

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John Cappa | Writer
Posted May 1, 2000

Stopping Old Iron

Step By Step

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  • First things first; ditch the drums. The only special tool you’ll need is a Dana 44 hub socket.

  • Remove the bolts holding the old brakes in place. The bolts, backing plates, spindles and brake lines are also removed. You can throw all this junk away.

  • The Wild Horses kit comes with both types of spindle seals. If yours uses the lip type, remove the old seals from the stubs and replace them with the ones supplied in the kit. Be sure to pry the installed seals out of the backs of the new spindles. If your Bronc has the seals pressed into the spindles then you can toss out the extra lip seals and install the spindles as they come.

  • Install the backing plates with the supplied 3/8 bolts and lock washers and torque them to spec. Temporarily install the calipers to check for clearance on the knuckles. This marked area is where we needed to hit with the grinder.

  • The wheel bearings from the drums (if they are in good shape) can be installed in the new hubs and rotors. New seals should be used here.

  • The hub and rotor assemblies are then installed on the vehicle with the drum brake adjuster nuts and washers. The original locking hubs are also reused. The stub axle retaining clips will no longer work so the supplied bolts and washers are threaded into the stubs for stub-to-locking hub retention.

  • The loaded calipers are then installed using the supplied caliper bolts. The Chevy brake line is routed between the shock and the coil on both sides of the Bronco.

  • The brake line feeding the front brakes is removed from the master cylinder. A No. 6 sheetmetal screw is then threaded two or three turns into the brass seat. The seat can then be pulled out with pliers to reveal the check valve (spring and small disc). Discard the valve and reinsert the seat.

  • Wild Horses offers a pressure differential, metering and proportioning valve all in one unit. It can be mounted on the fenderwell and plumbed to the master cylinder. We haven’t installed ours yet, but the brakes work great. If the rear begins to lock up under hard stops we’ll install it.

Oh yeah, rear disc brakes are great. They decrease stopping distance. They work better in mud and water. And one other thing: They’re useless if you still have drums on the front. Now, we could chastise you for owning a vehicle so old that it has front drums but the reality of it is that we like old trucks. Yep, even better than all the new funky widget this and antilock that. We’re pretty confident that we can tell when the wheels are skidding without the need for a vibrating, spongy brake pedal and flashing ABS lights.

So how do you put discs on the front of this older iron? Our ’71 Bronco had drums all the way around. The brakes worked as well as drums can, and water runs turned the pedal into a switch that merely lights up the brake lights. We called Wild Horses Four Wheel Drive to find out how to get some better stoppers on our steed. Among other early Bronco parts the company has a complete bolt-on kit to put discs on the front of drum brake Broncos. The kit will fit the Dana 30 and 44 frontends.

If you want to search for the parts yourself you’ll need spindles, brake hoses, caliper mounting brackets, and calipers from a ’76 or earlier Chevy ½-ton. In the later years (post ’76) there was a different spindle so the parts don’t interchange. You’ll also need a dozen 3/8x1½ fine thread bolts and lock washers, as well as hubs and rotors from a ’76-’79 Ford.

Interestingly, this disc swap will work on early Dodges too. The ’69-’74 drum brake trucks can use most of these parts, in addition to Chevy stubs for an easier, cheaper upgrade than using all Dodge parts. It even keeps the 5-on-5-½ bolt pattern. We took our Wild Horses kit and our unstoppable stallion to Extreme Automotive for the install. Extreme specializes in early Broncos and can do everything from supplying hard-to-find parts to complete frame-off restorations. Check out how Joe Monroe and Sam Suhr homogenize the Chevy parts into our Bronco.


Extreme Automotive
Canoga Park, CA 91304
Wild Horses