| Top off your disc brake conversion by adding POWER BRAKES !!!
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.|
|Granada Proportioning Valve
(see below for plumbing diagram)
|Part One - What You Will Need|
|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.
|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|
|Part Three - Disc Brake Installation|
|Part Two - Modification of Steering Stops|
|Part Five - Master Cylinder Installation|
|Part Four - Proportioning Valve Installation|
|Part Ten - Alignment|
|Part Eight - Tie Rod Installation|
|Granada Disc Brakes|
|?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.
|Caliper Attaching Hardware|
The existing steering stops on your Mustang may need to be trimmed in order to get the full available turning radius due to some differences in the Granada spindle. Trial fit the spindles and a wheel and see how much needs to be trimmed to allow full travel. On a 65-66 Mustang, you must trim off approximately 1/2" of the rearmost edge of the stop. Since you will have the strut rods disconnected to do this step, you might as well install some new rubber strut rod bushings. The bushings will ensure the car tracks straight when you slam on those new disc brakes.
|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.
This will be written up in more detail later, but basically, assemble the brakes on the Granada spindles and bolt them onto your ball joints with the appropriate tie rods or tie rod adapters.
Some Granada brake owners notice a rattle with their newly installed brakes. The rattle occurs on bumps and when driving slowly down the street, but always go away when the brakes are being applied. That is caused by the OUTER brake pads not being clamped tightly into the caliper when they are installed. There is a tab at each end of the pad that wraps around the ends of the caliper. Those must be REAL TIGHT or the outer pad will rattle. (see pic below)
These pictures show how to plumb the proportioning valve. There are basically THREE different ways that work fine.
1) Use a Granada proportioning valve and plumb as shown.
2) Use an aftermarket adjustable valve. In that case, simply plumb it into the rear brake line. The front lines simply use your old distribution block. (You may have to plug a port - auto parts stores have the plug. Be sure to get SAE inverted flare plug.)
3) Use a Granada proportioning valve in conjunction WITH an aftermarket adjustable proportioning valve. In order to make it work properly, the proportioning function must be removed from the Granada valve. To do so, the spring and inner piston need to be removed. Take the big nut/plug off. (On the right in the picture below) remove the spring and piston (about 1-1/4" long) and put the big nut/plug back on. That converts the proportioning valve to a simple differential pressure valve with no proportioning effect. Then plumb the aftermarket proportioning valve downstream of the Granada valve in the steel line heading to the rear axle.
Now, for the plumbing: The front port on the master cylinder goes to the inlet for the rear brakes on the combination valve. The outlet port from that connection goes to the rear steel brake line going to the rear axle. There is plenty of flex in that steel line to fit the comb. valve directly to it. I usually install the comb. valve vertically right behind the shock tower, bolted to the inner fender. Make the first connection to the rear steel line and then position the comb. valve for “best fit”. All other connections can be made up from that position.
The rear port on the master cylinder goes to any one of the three connections on the other end of the comb. valve, where the three form a “tee”. Since the three ports are just a connection, you can plumb to the easiest port. The other two ports on the tee in the comb. valve go to each of the front brake lines. You will probably have to fabricate some new 3/16” steel lines. You will need a double-inverted-flare flaring set to do this. That is not the same as a household type flare kit you would use for a sink or something. Don’t even think of using brass compression type fittings on a brake line. Be sure to “bench bleed” the master cylinder before installation, then bleed all brakes after installation, starting from the farthest away from the master cylinder and work your way towards it.
Fabrication of steel brake tubing. You will need a double inverted flare kit (about $30, not the same as your dad's old plumbing flare kit. Practice making flares on that scrap tubing I talked you into carrying home.) Use a large socket held in a vise as a guide to form the radii when bending the tubing. Stretch the tubing as much as you can when bending it around the socket and it won't kink. I make mock-up tubes with lengths of coat hanger wire. Just make the tubing match the shape and length of the mock-up and it will fit just right.
|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...
|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 Six - Brake Line Flaring and Installation|
|Part Seven - Brake Bleeding|
Click HERE for info on tie rods and adapters.
It is common on 65-66 cars to have to modify the length of the tie rod adjusting threads and the tie rod adjusting sleeves iin order to achieve enough toe-in.
To accomplish this, cut off 1/8" to 1/4" from the adjusting threads of ALL FOUR tie rods and cut off 1/8" from both ends of both adjusting sleeves. This will keep the tie rods from butting together before proper toe-in is achieved. The Granada spindles have different Ackerman geometry than the 65-66 cars.
|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 in 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.
If using stock styled steel wheels on a 65-67 Mustang:
Turn rotor outer bearing OD to 2.440"
Install 1/2" longer studs
Use 1/4" spacer
Now for the wheel issue. The outer bearing on the Granada brake rotor is supported by a larger O.D. chunk of metal than your original wheels will fit over. If you want to use your original black steel wheels, you can have that O.D. turned down on a lathe to 2.440" diameter for about $40 so the wheels will fit. Some wheels will still hit the caliper. You will have to machine as above, plus install 1/4" longer wheel studs and install a 1/4" spacer between the wheel and rotor. If it is easier, just buy the wheels from the Granada, most were 14" x 6" size and fit well on Mustangs. Most aftermarket wheels fit with no problem. Styled steel wheels from 70-back are more trouble. Magnum 500 wheels fit just fine with no mods. Some Granadas even had Magnums on them from the factory.
You also might have to grind the outer part of the caliper a bit to clear the wheel. Put about 10 layers of masking tape along the top of the caliper and then bolt up the wheel. If it hits, the tape will tell where. Drill some 1/8" holes about 1/16" deep every 3/4" along the area that needs clearance. Then, grind the caliper until the holes disappear. That way, the remaining depth of the drilled holes will tell how much you have ground off. Once it clears the 10 levels of tape, you are on your way.. Keep in mind that the caliper MOVES in and out depending on how much pad is in there...If it just clears with ˝ worn pads, it will likely rub when new pads are installed.
|Part Nine - Wheel Fitment|
|65-66 Mustang Steering Stop|
|This edge is the one to trim|
|Later model Mustangs may be different in design and some do not require trimming.|
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Automotive Repair Or Restoration Will Take Twice As Long And Cost Twice As Much As Originally Planned, Even After Careful Prior Consideration Of MustangSteve's Law
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|Removing the Old Pushrod From the Master Cylinder|
|Pry against Ears of Master Cylinder With 2 Screwdrivers.
It is tight, but it WILL come out.
|Clamp Pushrod in Vise|
|REAR Bowl of
|Left Front Brake|
|FRONT Bowl of Master Cylinder|
|Right Front Brake|
|This switch is used to ground the brake warning light when the valve senses a difference in pressure between the front and rear brakes|
|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.|
|DRIVER SIDE OF CAR SHOWN|
|Above image used with permission courtesy of MASTER POWER BRAKES|
|Anti-rattle clip goes to the rear of the inner pad|
|Bleeder points to REAR of car!|
|Tabs on each end of outer pad must clamp tightly on caliper or the pad will rattle and drive you nuts! **|
NOW AVAILABLE FROM MustangSteve
PROPORTIONING VALVE like above
see POWER BRAKE conversion page, part number PV-70