Mercury Stuff Logo

Disc Brake Conversion Information



Response to disc brakes

Someone posted this info for me a long time ago when I had the same question for my '63.


"We just recently changed from drums to disc. Procedure is same for 60-64 full size Fords. Your parts list will include disc brake calipers, rotors, dust shields and spindles from a 77-79 Thunderbird, Cougar, Ltd II or Montego. Remove all of your brakes, spindles included. The replacement parts will go right on your ball joints. The only thing you need to do is remove 1/8 inch material from the upper surface of spindle at the tie rod end. This can easily be milled off or just use a surface grinder, as we did.

This needs to be done to get castle on tie rod end far enough for cotter pin to go in. DO NOT REMOVE MATERIAL FROM NUT. All that’s left now is dual reservoir master cylinder. Ours came from 70 Mustang but many other Ford cylinders will work. To do this job right, I would replace upper and lower ball joints and rebuilt calipers, which are cheap. You will need to fabricate some brake lines to accommodate the new position of brake hoses. This swap works great and only takes about 4 hours time. The finished job is factory appearing and boy does it stop quicker!"

NEED:
1. 4 ˝" bolt pattern uses 74-79 t-bird, cougar, torino
2. 5 " uses 74-79 Lincoln
3. 2 calipers (to match spindles)
4. 2 inner bearings (t.m.s.)
5. 2 outer (t.m.s.)
6. 2 wheel seals (t.m.s.)
7. 2 brake hoses from 75-80 Granada
8. 1. 1 master cyl. 72 f250 w/ disc brakes
9. 1 proportion valve D9AZ2b257D
10. 2 tie rods (t.m.s.)


This is most of the large parts you'll need. I used 74 Torino spindles with 74 torino tie rods and there wasn't any problems. I replaced upper and lower ball joints with 64 Galaxie parts without any problems also. I never needed to grind any parts, but maybe with a different vehicle it might be needed as stated in the other post. While your at it make sure your control arm bushings are in good condition. It's the easiest time to replace them!. Good luck!

disc brakes swap

A note from the Mustang Shop:

Richard Ireland, the great guy who provided us all with the T-5 swap information, recently did this conversion on his own car and was kind enough to send along some pictures and a parts list. The follow text, however, came from Dan Jones. The original posting location of the text is unknown. The difference in the text and the pictures is that Dan used parts from a '79 Granada, whereas Richard uses parts from a '77. Same stuff though.

I'll start you off with the big giant text info, down at the bottom you'll find the pictures and the parts list.

Drum to Disc Brake Conversion
----------------------------------------------------------------------


Complete Front Spindle Swaps (a.k.a. "The Granada Spindle Swap")

The "Granada Spindle Swap" is a popular and effective way to increase the braking power of older Mustangs (and other Ford and Mercury automobiles). What makes this swap attractive is the fact that the entire spindle and brake assemblies (but not necessarily the individual parts) of many 1960's and 1970's Ford, Lincoln, and Mercury autos are directly interchangeable.

Since factory parts are used, the cost is reasonable and everything needed is available from your local junkyard and auto parts store.

Some cars are better than others as donors because they came equipped with 11" diameter brake rotors for increased stopping power over the more common 10" rotor size. The spindle and brake assemblies of 65-70 Ford Mustangs or 67-70 Mercury Cougars (and probably other cars like Fairlanes, Falcons, Mavericks and Comets, etc.) can be used, but most of these cars came with 10" rotors. Exceptions are the early Shelby Mustangs, Boss 302's, and Boss 429's (any others?).

At least some of the 75-80 Ford Granada’s, Mercury Monarch’s, Lincoln Versailles and 71-73 Mustangs and Cougars (what about Torino’s and Montego’s?) have the larger 11 inch diameter discs. The Granada/Monarch/Versailles cars are the most popular donors for this swap because they have the larger rotors, are relatively common (and therefore inexpensive) in junkyards, and have parts that are still stocked by local auto parts stores. Also, if you are hunting front brake parts from a Granada, Monarch, or Versailles, check the rear for disc brakes. Some Granada’s and Monarch’s, and all Versailles came with disc brake equipped 9" rear ends.

Note: There is an open question about the Versailles front spindle diameter. When swapping from drums to discs, from the donor car you'll need the entire left and right side spindle assemblies (spindles, splash shields, calipers, rotors, etc.), proportioning valve/metering block, and appropriate master cylinder and power brake booster. There's also a chance that you will need new wheels since some of the old 14" wheels were designed for drum brakes only and will not clear the calipers of the new set-up. One list member had problems with 14" disc-type styled steel wheels. When I bought my car it had 14x6 Torq Thrusts style wheels (I don't know if they were made by ARE or not), but they were made to fit drum brakes and wouldn't clear the big disc brakes. I ran 14" disc brake style steel passenger car wheels for several weeks until I found some used 14x6 Torq Thrusts meant for disc brakes. I ran those until I got new 15x7 Torq Thrust wheels. Of course 4-lug wheels from early 6 cylinder Mustangs will need to be replaced with 5 lug wheels. If you are using the Granada/Monarch/Versailles spindles, you will also need outer tie rod ends which fit those cars.

In all cases you will need the proper master cylinder (disc/disc, disc/drum, or drum/drum) for your brake configuration due to differing disc and drum brake fluid volume requirements. If you have a 1964-1966 model year car with a single reservoir master cylinder, you should consider upgrading to a later style dual reservoir master cylinder for safety reasons.

If you have a high performance engine with low engine vacuum, you may need an additional vacuum reservoir for proper power assist operation. These are inexpensive and readily available from a variety of hot rod parts places like Summit Racing.

One additional note when switching from manual drums to manual discs is that you may notice an increase in effort to stop at a given rate. This is because drum brakes are "self-energizing" (i.e. energy from the braking effort assists in forcing the shoe against the drum, decreasing the required effort) while discs are not.

The trickiest part of the swap is that you may need to do a little brake line work. Your donor brakes may require different size fittings so cutting and re-flaring may be necessary. This is no big deal, if you use the proper double-flaring tool.

Since you'll be getting most of the parts from a junkyard donor car, figure on rebuilding the calipers, replacing or re-packing the wheel bearings, and getting a rebuilt master cylinder (use the part from the donor car as a core). Also check the condition of the pads, rotors, and rubber lines and replace as necessary. Don't forget to pick-up some of the little copper crush washers that complete the brake line to caliper seal. If you mix and match parts from several donor cars, keep a note with the model and year of the donor cars for future reference.

When installing new brake pads, it's best to stick with similar pad and shoe materials. Mixing brake pad materials (organic vs semi-metallic or different manufacturers) can be used to correct fore-and-aft brake bias problems, but it is a trial-and-error process and the results can vary depending on brake temperature. A better solution is to plumb in an adjustable proportioning valve to vary the fore-and-aft balance. Various types of adjustable proportioning valves are available. Some use a lever adjustment with a discrete number of positions, others use a continuously variable knob adjustment. They can even be plumbed into the cockpit for on-the-fly adjusting.

I performed the Granada spindle swap on my '66 fastback with great results. The car was originally equipped with manual drum brakes all the way around and a single reservoir MC. They were inadequate at best and downright scary at worst. I upgraded to a manual disc/drum configuration and dual safety reservoir MC using donor parts (two complete spindle/brake assemblies and a proportioning valve/metering block) from a 1979 Granada with 11 inch diameter rotors. I replaced one rotor (the other was nearly new and was re-surfaced) and rebuilt the calipers. I purchased a pair of new 1979 Granada tie rod ends and a disc/drum master cylinder for manual brakes. I also bought new rubber lines (with circular reinforcements to resist ballooning under pressure) and added an adjustable proportioning valve. I also took the opportunity to fabricate a set of adjustable steering stops.

I ran into two minor problems during the swap. The first concerned the master cylinder. I was unable to obtain the correct master cylinder (65-66 Mustang with manual disc brakes) locally. I improvised by modifying a master cylinder from another application to fit. One of the list members has since informed me that the master cylinder from an early Bronco with manual disc/drum brakes should work without modification.

The second problem concerned the brake pads. After completing the swap, the car pulled strongly to one side. I traced the problem to a defective set of pads. Even though the pads appeared identical, I swapped them side-to-side and the car pulled to the opposite side. I replaced the pads with another set and everything was fine.

An unexpected bonus of this swap is that the new tie rods and spindles are beefier than the originals.

The Spring 1989 issue of Mustang Illustrated article "Drums to Discs without Braking the Budget" covers this swap but some of the details on years may be incorrect.

THE PARTS LIST
Source Part Number Qty. Description Unit/Total Price
Western Auto S13 2 77 Grenada inner wheel bearings $5.99/$11.98
AutoZone 693226 2 77 Grenada outer wheel bearings $6.97/$13.94
Western Auto 71-19221 2 77 Grenada Wheel Seals $1.89/$3.78
Salvage yard N/A 2 77 Grenada Spindles (with backing plates and calipers for core charge) $30.00/$60.00
AutoZone 561720 2 77 Grenada brake rotors $39.99/$79.98
Western Auto 18-4069/18-4070 2 77 Grenada brake calipers $13.99/$27.98
Western Auto BH36649 2 77 Grenada brake hoses $18.99/$37.98
Western Auto RR-D91 1 77 Grenada brake pads $12.99/$12.99
Plaza Auto Parts 258340 2 Brake hose adapters $1.82/$3.64
Toms Auto Parts H5527 2 77 Grenada caliper hardware kits $11.04/$22.08
Master Power Brakes N/A 1 Dual reservoir master cylinder $69.95/$69.95
Master Power Brakes 1350K 1 Proportioning valve $129.95/$129.95
Mustangs Unlimited C5ZZ3590ARS 01 1 Idler arm and Pitman arm (GT-350 kit) $119.95/$119.95
Dallas Mustang 1431 1 1 Center (drag) link $96.28/$96.28
AutoZone SL77 1 Stabilizer end link kit $6.94/$6.94
AutoZone n/a 2 77 Grenada outer tie rod ends $31.00/$62.00
Salvage yard N/A 2 5 lug rims (14 inch) $10.00/$20.00

TOTAL COST: $779.42


Info Courtesy of Norman Master




TAGS: Ford, Lincoln, Mercury, Brakes, Disk, Disc, Brakes

This site is in NO WAY affiliated with the Ford Motor Company.