Let's cut right to the chase. Disc brakes simply work better than drums. If you have a classic Ford with drum brakes and drive it once a month to the local cruise night, you might want to turn the page. However, if you have some decent power under the hood and like your car to stop as well as it goes, then disc brakes are going to be part of your upgrade plan. A weekend in the garage upgrading the front drums to a set of discs with new calipers and hardware will really make a difference. While that difference is certainly measurable, even by the seat of your pants, you can make it even better by ditching the rear drums and going four-wheel-disc on your ride.
Adding a rear disc brake kit can not only reduce your braking distances, but it can also make for a total brake package that reduces reaction time from the brake pedal to the rotor (drum brakes require a larger gap between the brake shoe and drum, resulting in more pedal movement before brake application). Furthermore, many owners dislike the "disc/drum" combination behind their fancy aftermarket wheels. You've paid good money for those nice aluminum 18-inch five spokes, why have some blacked out or body-color brake drum sitting behind it when you can have a shiny brake disc that tells the world your classic Ford muscle can stop just like a new car.
The biggest problem with upgrading to rear discs is the cost. For many, the cost of a rear disc upgrade just about mirrors the cost of the front disc upgrade they've already installed, and while the rear disc setup does help, it is not as big an improvement as upgrading the front drums to disc, as the front performs the majority of the braking needs. In the end, the owner feels cheated for spending big-bucks on the rear disc to not "see" the same improvement as when they installed their front disc conversion. All is not lost, however, as the folks at CJ's Pony Parts have partnered with the brake hardware experts at The Right Stuff Detailing to offer a rear disc brake conversion that will fit most early Ford rears at a jaw dropping price!
1. Begin the rear disc upgrade by raising the rear of your vehicle and supporting it safely on a pair of jackstands positioned on the axle tubes or the rear torque box/framerail area and remove the rear wheels.
2. Remove the brake drums and then rotate the axle shafts until the access hole in the axle flange lines up with one of the axle retaining nuts, so that a ratchet and deep socket can remove said nut. Rotate the axles as needed to remove the three remaining nuts per side.
3. If your axles have been installed in the axle housing for any length of time, you will most likely need a slide hammer to remove them. This homemade tool that Classic Creations of Central Florida made some 20 years ago still gets the job done around the shop. Sometimes you can flip the brake drum over and bolt it back onto the axle for leverage to pull the axles by hand.
4. Once the axles are free, the rear drum brake assemblies, including the backing plates, will be loose. Simply break free the brake hard line from each side and remove the drum brakes as a complete assembly. There’s no need to disassemble brake shoes/springs/etc.
5. The axle and brake retaining bolts, called T-bolts, sometimes fall out during drum brake removal and need to be in their stock mounting configuration (threads facing outward) for the disc brake kit mounting hardware.
6. The only modifications required to your rear axle hardware is the removal of the axle retaining plates on each axle. These will no longer be required, as the disc brake conversion bracket becomes the new axle retainer on each side. If your axles require new bearings, you can remove the retainers at the time of bearing replacement. Otherwise, a cut-off wheel and a pair of locking pliers will see to the removal of the retaining plates.
7. After the axles have had their retaining plates removed, the axles can be returned to the axle housing and fully seated into place. Now is also a good time to replace any questionable axle shaft oil seals before axle installation.
8. You will notice that once the axles are fully seated into the axle housing, the axle bearings protrude out of the housing flange by a 1⁄16-inch or so. To prevent bending the brake caliper adapter brackets, a set of shims are provided to take up this difference.
9. Depending upon the bearing design you might only need one shim, but two shims (per side) are supplied and are what was required on this ’67 Mustang fastback to have the axle bearings become “flush.”
10. The brake caliper adapter brackets slip over the T-bolts, sandwiching the shims between the adapter brackets and axle flanges. The original T-bolt retaining nuts (or new ones if yours are rounded/worn) are then installed to secure the brackets and retain the axles once again.
11. The rear disc conversion kit includes three different spacer lengths to space the caliper mounting brackets inboard in relationship to the adapter brackets just installed. The instructions also state to start with the medium length spacers first. The spacers help center the calipers over the brake rotors, so some trial and error/mock-up is entailed to get it right.
12. Install the four included bolts in each adapter bracket, facing inwards toward the fuel tank, followed by the medium length steel spacers over the bolts on the back side of the adapter brackets.
CJ's rear disc brake kit, PN DBR21, rings the register for only $427.99! The kit will bolt on to any Ford 8-inch rear axle or 9-inch "small bearing" rear axle, which means it will fit Mustang, Fairlane, Comet, Torino, Falcon, Maverick, and others with these axle housings. The kit includes 11.25-inch vented rotors, single-piston calipers loaded with brake pads, DOT rubber brake hoses, caliper-to-axle housing mounting brackets, a pair of parking brake cables, and all required mounting hardware/spacers. All parts are brand new and ready to install right out of the box. If you're looking for something with a little more flash, CJ's offers optional kits that include drilled/slotted rotors and powdercoated calipers in red, black, or natural that are still less than $500 for the complete kit! Note that this kit will usually require 15-inch or larger wheels, which isn't normally a problem with our readers, but we did want to note it.
13. Follow the spacer installation with the caliper mounting bracket on each side and secure with the included flat washers and nuts.
14. The rotors in the base kit we’re installing here are solid-face vented 11.25-inch discs (zinc-plated rotors that are slotted and drilled are optional). Some axle shafts might require the flange to be turned down on a lathe to clear the ID of the rotor hub, but in our installation there was plenty of room for the rotors to slip right on.
15. The loaded calipers slide over the caliper mounting brackets and are then secured by the included caliper slide pins. Install the lower pins first, but leave them loose enough for the caliper to be moved as needed to line up the upper slide pin and install it through the bracket, brake pads, and caliper casting. Once both pins are in place they can be tightened down.
16. To determine if the medium spacers are going to work for your particular installation, inspect the brake pad to rotor spacing by looking at the rotor’s edge straight on for each side of the axle. If the gaps on both sides of the rotors are the same, the medium spacers can be retained. If the gaps between the pads and rotors are not the same, the calipers will need to be moved in or out by using the longer or shorter spacers, respectively.
17. Brake hoses are included with the kit (rubber standard, optional braided stainless steel) and feature a banjo-style fitting at the caliper end and a standard 3⁄16-24 inverted flare at the opposite end. When installing the banjo end of the hose, be certain that the included copper sealing washers are used, one for each side of the banjo fitting, as shown here.
18. Route the flexible brake hoses as needed to clear any suspension or exhaust parts so that a location can be determined for the included brake hose mounting brackets. These two small brackets will require welding to the axle tube. We simply shortened the brake hard line and connected the brake hoses, as shown here, to determine final location for welding. If you do not have access to a welder, you can secure the lines with tie wraps for a drive to your favorite exhaust shop for a quick hit with a MIG welder.
19a. The rear disc brake kit includes a pair of parking brake cables. Depending upon your OE cable type and routing, these new cables (or your originals) may require rerouting or to be shortened. The folks at The Right Stuff Detailing even offer to exchange cables for different lengths (according to the instructions).
19b. The cable attachment to the parking brake mechanism is a simple two-step procedure; pull the cable through the bracket and return spring and the push the cable down into the parking brake actuating arm. We found that a small screwdriver will aid in pushing the cable into place.
20. Once you have wrapped your rear disc brake conversion, there is a small trick to bleeding the rear calipers. Due to the caliper’s casting design (these are not Ford calipers), the bleeder screws do not point completely level as installed, trapping a bit of air in the piston chamber. You will have to unbolt the caliper and pull it back as shown to raise the bleeder screw location and rid the caliper of all trapped air.
21a. Using the left rear caliper as an example, we have the caliper positioned in our first photo as it would be installed on the caliper mounting bracket. You can see how the bleeder points downward, leaving a potential air pocket in the caliper casting that would lead to a soft pedal and spongy brakes.
21b. In the second photo, we have repositioned the caliper for bleeding the brakes (as we show from the front in photo 20 at left) and you can see how the caliper’s bleeder is now positioned to allow any trapped air to easily escape during the brake bleeding process.
22. As noted in our opening text, the rear disc brake conversion kit does not support 14-inch wheels. The 15-inch wheels are considered a minimum for the conversion kit. The owner of this ’67 fastback hasn’t decided on the wheel and tire package yet, but we dropped this 17-inch American Racing Shelby wheel over the disc conversion with no issues and the gray centers really worked well with the bright red paint on the car.