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

Part Three  –  Disc Brake Installation

Part Four  –  Proportioning Valve Installation


Part Five  –  Master Cylinder Installation

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

To remove the old pushrod from the master cylinder clamp the pushrod into a vise and pry against the ears of the master cylinder with 2 screwdrivers. It’s tight, but it will come out!

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.

Best place to mount the hose bracket is mid-way front to rear under the control arm. The hose is held to this bracket with a spring clip.

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…

Part Eight  –  Tie Rod Installation

You will need outer tie rod adapters in order to get the spindle to accept the tie rods and it be tight and able to accept a wheel alignment.
If you are running a 65-66 Mustang then you want these adapters: TRB-65GR
If you are running a 67-69 Mustang then you want these adapters: TRB-67GR

Part Ten  –  Alignment

65-66 with Granada spindles – stock A-frames       Caster 0       Camber 0    Toe 1/8″ IN
”                       ”                             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.

Technical Information


What bearings do I use for a 69 Mustang?

69 spindles have smaller axle on all except BOSS 302 and BOSS 429.  69 non-Boss spindles use A2 and A6 bearings. 70-73 spindles have larger diameter axle and use A12 and A13 bearings.

69 non-Boss spindles use smaller tie rod, same as 67-69 Mustang.

70 spindles use a larger tie rod that is a little larger than the 67-69 spindle, but smaller than the Granada spindle.

What hubs do I use on what spindles?

Hubs and rotors from 65-73 will fit either spindle as long as the bearings that fit the spindle axle are used. The OD of the bearings is the same for all years mentioned.

So, the 70-73 spindle has larger axle but the rollers in the bearings are actually smaller than the 65-69 bearing rollers.

Will your rear brakes work on the Torino (new style) bolt pattern?

Yes.  The big bearing cobra rear brackets will work with the Torino (new style) bolt pattern using 3/8” mounting bolts and will also fit the older style large bearing 9” flanges using ½” bolts.

The brake gap needs to be 2.50”.  That is measured from the outside of the housing flanges to the outside of the axle flange (where the rotor would fit, but not including the thickness of the rotor.

Brake Pedal FAQs