Keeping It Simple With A Factory-Style Ford Front Disc Upgrade

It’s long been common practice for fans of muscle-era cars to upgrade the four-wheel drum brakes, typical of that period, to front discs. For years, doing so required sourcing parts from donor vehicles, though finding the needed items from junkyards has become increasingly difficult.

Thankfully, the aftermarket stepped up to reproduce many of the items that have vanished from the salvage market, which was a great help to us as we looked to add front discs to a classic 1964 Mercury Comet. Ford Motor Company didn’t offer disc brakes for the cars built on its com pact platforms during the ’64 model year, though it did make front discs an option for the ’65 Mustang. Given how popular early Mustangs have been for decades, it’s no surprise that all the brake parts are readily available as brand-new items. The ’64 Comet we were working on has the same suspension architecture as the ’65 Mustang, so those discs are a bolt-on upgrade.

Of course, these days, owners of early Mustangs and related models have myriad choices when upgrading their brakes, with offerings going well beyond what the factory ever dreamed of providing back in the ’60s. However, for this project, the Comet’s owner wanted to be able to retain the stock 14-inch steel wheels so that he could reinstall its factory wheel covers, which replicate the look of chrome reverse wheels.

Very few contemporary brake kits will clear 14-inch wheels, though the original ’65 Mustang discs were intended for wheels of that size. We went to Summit Racing to do some shopping and landed on a kit from Leed Brakes that included everything we needed—rotors, calipers, mounting brackets, bearings, hoses, and all associated hardware. What really appealed to us was that this kit included a dual-circuit master cylinder and proportioning valve, and was intended to be used without a power booster. That was important because the Comet’s original firewall braces are welded in and don’t leave much room for a conventional booster. Plus, the car owner simply preferred to stick with a manual setup.

As a bonus, thanks to the design of the ’65 Mustang’s optional disc brakes, we did not have to change the Comet’s spindles—Ford designed caliper brackets that mount to the drum-brake spindles, and the rotors install directly in place of the drums. When we were done installing the Leed Brakes kit, the Comet looked like it might have come from the factory with the front discs. This may have been the simplest front disc conversion we’ve ever done—check out the photos and captions to see the process.

Photos were removed by unknown buttheads.


This 1964 Mercury Comet Cyclone left the factory with four-wheel drum brakes, and while the car’s owner wanted to upgrade to front discs, he also wanted to retain the factory wheel covers used on Cyclones that give the look of a chrome reverse wheel. Of course, to retain the 14-inch wheel covers, he would have to use 14-inch wheels, and that severely limited the number of disc-brake setups we could use.

Though the ’64 Comet did not offer front disc brakes as an option, the 1965 Mustang did, and those brakes are still readily available from the aftermarket. Since the early Mustang and this Comet share suspension architecture, the Mustang brakes are a bolt on for the Comet. This kit from Leed Brakes is essentially a reproduction of the parts used for the disc brakes that were optional on the ’65 Mustang, with 11-inch vented rotors, four piston, cast-iron calipers, and the required mounting brackets and splash shields. The exception is the upgrade to a dual-circuit master cylinder and adjustable proportioning valve.

The installation begins with removal of the stock drum-brake assemblies. The brake hard lines will be reused, so we took care not to damage the fittings when disconnecting the flex hoses. The disc brake kit includes new flex lines for the calipers.

Once the plumbing is disconnected, removing the four bolts that fasten the backing plate to the spindle will allow the entire brake assembly to come off with the shoes, springs, and wheel cylinders still in place.
This bracket is a key element in making this disc swap so simple. Rather than requiring new spindles to accommodate the discs, as is often the case with American cars of this period, this caliper bracket mounts to the existing spindle using the drum-brake backing plate bolt holes. The cast caliper bracket is a reproduction of the one Ford used for the early Mustang.

The caliper bracket mounting bolts also secure the included splash shields, so the shields need to be put in place during this step. The calipers mount toward the front with this setup.

The kit includes new wheel bearing sets, and after driving the new races into place, the rotors are mounted to the original spindles. These rotors are essentially a new, stock replacement for a ’65 Mustang part.

The calipers in this kit are cast-iron, four-piston units that use a fixed mounting—they do not slide. Here again, the calipers are brand-new versions of the ones offered on the ’65 Mustang. The set in the kit came “loaded,” meaning they already had a set of pads installed. We slipped them over the rotors and bolted them to the brackets.
The flex hoses used with these calipers thread directly into each caliper body, so they must be installed before the line is connected to the hardline on the chassis.

Our conversion kit was intended for a few different Ford applications, so it included some fittings and such that we did not need. Among them were these hardline adapter fittings, which would merge the disc-brake flex hoses with the hardlines on some drum-brake cars. For this Comet, the hardlines connected directly to the new flex hoses.

One of the things our car owner wanted to change in the brake system was the master cylinder—like most cars of the period, this Comet used a single-circuit master. These work fine when everything is in order; however, if a leak develops anywhere in the system, before long, the driver will find zero braking available. Our disc-brake kit included a dual-circuit master from a later Ford application.

We were pleasantly surprised to find that our stock-style disc-brake kit included an adjustable proportioning valve. This one will mount neatly right underneath the master, but before putting it on, we needed to mount the pressure switch that activates the brake lights, which was also included.

The Comet doesn’t have much room around the master cylinder thanks to welded-in braces that tie to the shock towers. Fortunately, the dual-circuit master we’re using will still fit, though adding a power brake booster would have posed a problem.

The brake kit also included a new “pigtail” electrical connector for the brake-light switch. The Comet was using the same type of switch with the drum-brake setup, but someone before us had cut off the factory connector and was using universal spade terminals, so the new pigtail came in handy.

As mentioned previously, the disc-brake conversion kit from Leed was intended for a few different Ford applications of this period, so there were some items we didn’t need, but we were impressed that the kit was so complete.

With the installation complete, the stock-type front discs don’t look out of place on the Comet, even though they were never offered during the ’64 model year. We did find that the factory 14-inch drum-brake wheels contacted the calipers, so we had to use a different pair. Ours came from a later Mopar application, but the correct Ford-style 14 x 6-inch disc-brake steel wheels are available from a variety of sources brand-new, including Coker Tire’s Wheel Vintiques.

Sources:

Coker Tire / Wheel Vintiques
866-516-3215
cokertire.com



Leed Brakes
716-852-2139
leedbrakes.com



Summit Racing Equipment
800-230-3030
summitracing.com