Granada Disc Brake Conversion for Classic Mustangs

This disc brake swap will work on all 64-1/2 to 73 Ford Mustangs as well as any other mid size Ford using the same type of front suspension.

Part One  -  What You Will Need

Start out with removal of your drum brake spindles and outer tie rods, master cylinder and brake distribution block. This is a good time to replace upper and lower ball joints if needed. Upper A-frame removal is not required unless you will also be replacing the upper A-frame bushings or spring saddle perch. Spring removal is NOT REQUIRED unless the upper A-frames are to be removed.

The disc brakes shown here are from a 1975 to 1980 Granada, Versailles, Monarch, Maverick, or Comet. The ones you find in a wrecking yard probably will not look this clean. Look for rotors that are marked with MIN. THICKNESS .810", and a single piston caliper that is attached with a sliding retainer held in place by one bolt, usually with an allen head. All the above cars are REAR STEER, meaning they have the tie rods located aft of the front wheels, instead of in front of the wheels.  Note: Versailles disc brakes use a larger diameter lower ball joint stud, and require the use of an adapter to be able to bolt up to the Mustang lower ball joint, (more on that later). Caution: There are other Ford brakes that LOOK similar to the Granada discs, but have rotors that are 1" thick or thicker. Those will not fit a Mustang. If you have a set of brakes that look similar to these, but has a rotor thickness of 1" or more, those brakes will NOT work on your Mustang or other classic Ford.

Granada Disc Brakes

Caliper Attaching Hardware

Granada Proportioning Valve (see below for plumbing diagram)

You will need the following parts from the donor car:


Spindles, backing plates, rotors, calipers, caliper mounting hardware (which consists of flat spring, slide clamp and attaching bolt), the rubber brake hoses, the frame brackets where the rubber hoses mate up to the steel lines at the frame rail, the threaded flare nuts from that same fitting (they are a unique size), the proportioning valve along with all it's flare nuts intact, and any steel brake lines that have the coiled wire wrapped around them. The coiled wrap will be removed and installed on your new steel lines, so just cut the tubes with side cutter pliers for quick and easy removal. Same for the proportioning valve.  Do not try to loosen the flare nuts while removing the valve, just cut the tubes about 1" away from the valve.  That way, you can use a box end wrench to remove the nuts when you get home. Take note of which fittings on the valve went to where.  If the donor car has no proportioning valve available, get one from any mid sized Ford car or Mustang with front discs and rear drums.  Try to get the valve from a car that still has brake fluid in the system to avoid purchasing one with dried out seals.

You will NOT need the ball joints or the upper a-frame.  In some cases the outer tie rod ends can be utilized, get them only if in perfect condition. If your car is a 65-66, 6 cylinder Mustang, don't bother getting the tie rods. More on the tie rod issue later...

New Brake Parts that you may consider when doing this installation:
Pads, Rebuilt calipers, Rotors, Hoses, Wheel bearings, Cotter pins, Hardware, Tie rods (see Part Eight)

You may also need Tie rod adapter bushings (see Part Eight)

Also required will be brake fluid, master cylinder (if being replaced) and new steel brake lines.

Tools will include various sizes of SAE sockets and box end wrenches, SAE inverted flare tools, allen wrench, adjustable wrench, needle nose pliers, SAE inverted flare tube flare tools, and possibly a small tubing bender.

Part Two - Modification of Steering Stops

Later model Mustangs may be different in design and some do not require trimming.

Part Three - Disc Brake Installation

Anti-rattle clip goes to the rear of the inner pad

Tabs on each end of outer pad must clamp tightly on caliper or the pad will rattle and drive you nuts!

Part Four - Proportioning Valve Installation

This switch is used to ground the brake warning light when the valve senses a difference in pressure between the front and rear brakes

Part Five - Master Cylinder Installation

Use your original Mustang pushrod with manual disc brakes when using Maverick master cylinder
Ft bowl = rear brakes
Rear bowl = front brakes
Bench bleed master cylinder before installing.

Part Six - Brake Line Flaring and Installation

These various sized fittings are available at
PepBoys. They have the correct ends for the
Maverick Master Cylinder. FedHillUSA also
carries any size tube nut you could ever need.

I HATE ADAPTERS! They look like a botched
installation and provide more potential for
leaks.

Part Seven - Brake Bleeding

Brakes won't bleed properly? Be sure you have the calipers on the right side of the car. The bleeder screws should point straight rearward, NOT UP...

(Bleeder points to REAR of car)!

Above image used with permission courtesy of MASTER POWER BRAKES

Part Eight - Tie Rod Installation

Part Nine - Wheel Fitment

Part Ten - Alignment

65-66 with Granada spindles - Stock A-frames       Caster 0       Camber 0    Toe 1/8" IN
65-66 with Granada spindles - Lowered                      +3                      0               0

67-73 use stock specs, unless lowered.  Lowered cars need more caster typically.

This is not gospel, but I have had good luck with these. If you have a 65-66 that is lowered, you WILL be able to tell these spindles steer differently and are prone to severe bumpsteer. That is the reason for the zero toe. If you have a choice, use original, same year as car, Mustang spindles and disc brakes. The car will steer and corner better.