January 2012
By Tim Suddard
This stainless steel, classic car drum brake to disc brake conversion kit for drum brake spindles makes it easier than ever to get into safer braking

This stainless steel, classic car drum brake to disc brake conversion kit for drum brake spindles makes it easier than ever to get into safer braking

Stainless Steel Brakes Corporation was the first to offer disc brake conversion kits for vintage Mustangs more than 25 years ago. This pioneer of safer classic car braking now offers a simple bolt-on four piston front disc brake conversion kit for Mustang drum brake spindles.

SSBC’s new A 120 disc brake conversion kit is a nice reproduction of the original four-piston Kelsey-Hayes front disc brake, which bolts right onto your Mustang’s drum brake spindle without any modifications and fits inside 14• or I5-inch wheels. For under $1,100, the kit comes with 43mm four piston iron calipers, 11.25-inch unidirectional vented iron rotors on 5×4.5- inch lug pattern hubs, hoses, and plated Grade 8 hardware.

For the safest, most effective braking performance possible, we opted for a power booster and dual master cylinder, also from Stainless Steel Brakes. Vacuum-boosted power minimizes pedal effort. Dual braking provides some form of braking should one of the two systems fail, which will get you safely stopped in an emergency.

We’re doing this conversion on a ’65 Mustang hardtop at Mustangs Etc. in Van Nuys, California. What struck us most about this car is its original status with factory four-wheel power drum brakes sporting four C3AE original brake drums with Ford casting numbers, along with the factory exhaust system and original suspension components. Though none of these items are serviceable, it is amazing to find factory parts on a 46-year-old automobile.

1. This is the Stainless Steel Brakes A120 classic car drum brake to disc brake conversion kit. With this kit, you don’t have to search all over for the right spindles to accomplish this swap, just pack bearings, hang rotors, and install calipers.

2. We could have saved a few bucks with manual disc brakes, but decided to go with a power booster to reduce pedal effort and improve braking efficiency. The dual braking master cylinder provides back-up stooping power should a front or rear system fail with something like a ruptured wheel cylinder or burst brake hose.

3. Classic Tube provided us with all of the brake lines and hoses required for a ’65-’66 Mustang with a dual braking system, which was federally mandated beginning with the ’67 model year.

4. Here, Gil Roiz of Mustangs Etc. begins the front drum brake removal. With the SSBC conversion, you don’t have to remove the drum brake spindle. Because Gil had a pair of spindles cleaned up and ready to go on this car, he decided to remove the old drum brakes and spindles as assemblies.

5. The brake hose and line are disconnected using a 2/3- inch tubing wrench. That’s a 9/16-inch open –end wrench on the hose end.

6. Gil uses an impact hammer to jar ball joints and tie-rod end loose, which prevents the boot damage that can occur with a pickle fork.

7. Gil felt this should be an install performed on a workbench, which is why he had spindles already prepped. The caliper bracket is installed first.


8. Then install the dust shield using the cadmium-plated Grade 8 hardware provided Torque is 35-45 ft/lbs. Gil strongly suggests the use of a high-temperature thread locker on brake hardware. Don’t overdo it.

9. The rotors are wiped down using brake cleaner. Although we’re using a shop towel here, it is better to use a lint-free tack rag for best results on these freshly machined surfaces.

10. Gil believes in hand packing bearings to ensure complete grease saturation using a high temperature grease. Massage until rollers are completely buried in grease.

11. Seals are installed and seated. You can seat the seal using a 2×4 block of wood, which won’t turn the seal. Another alternative is an appropriately sized 1/2-inch drive socket gently manipulated with a hammer.

12. Lay down a thin film of wheel bearing grease on the races and seat the outer bearings once the rotor and inner bearings are properly seated. Spin the rotor and feel for binding.

13. There are many schools of thought about how to seat and torque brake rotors. Our best experience calls for tightening the castle nut with a wrench as shown while spinning the rotor to seat the bearings. If there’s no binding, loosen the castle nut, spin the rotor to check for smooth operation, and tighten again to snug.

14. Line up the castle nut or retainer to install the cotter pin. Fold the pin over to secure and ensure the pin does not touch the grease cap.

15. Don’t install the dust caps by beating the daylights out of them with a hammer. Instead, use this poor man’s installation tool-a 5-inch length of 2-inch exhaust pipe.

16. The caliper is fitted and checked for proper centering. Shims can be used to get the caliper centered if necessary.

17. Again, Gil suggests the use of a good high temperature thread locker before torquing the caliper bolts to 45-50 ft-lb.

18. Brake hoses are installed using the provided copper sealing washers.

19. Gil uses pad-silencing grease on the back of each brake pad, installing them like this in each caliper. All four pads are identical. Do not get silencing grease on the friction surfaces.

20. Pad retainers install like this. Use a high• temperature thread locker on the bolt threads.

21. Gil installs the brake/hub/spindle assembly with a little help from a pry bar. The pry bar bears against the lower control arm so the spindle will clear the upper ball joint. Keep in mind it is not necessary to remove your spindles unless there’s damage or excessive wear.

22. New brake lines from Classic Tube have been installed in the interest of safety and convenience.

23. For safety and convenience, we’re also replacing the single master cylinder with a dual master cylinder and power booster. Here, Gil begins the swap by using a 1/2-inch tubing wrench to disconnect the line from the original single reservoir master cylinder. A 9/16-inch box end wrench is used at the power booster. The factory drum brake power booster cannot be used with a dual brake system master cylinder because it won’t clear the shock tower.

25. The original brake hydraulic plumbing has to be changed to create a dual braking system. Gil uses a tubing wrench to disconnect the manual drum brake lines at the brass distribution block. Classic Tube has provided new galvanized steel tubing for our disc brake conversion.

26. Stainless Steel Brakes provides this distribution block plug, which will isolate the front brakes from the rears to create a dual braking system. The distribution block is for the front brakes only and connect to the large rear master cylinder reservoir.

27. Gil assembles the power booster and adjusts the pushrod to brake pedal height. You want as much thread penetration as possible here-at least 3/4-inch or more.

28. Unless originality is important to you, try this tip from Gil. Use studs through the firewall for easy power booster installation. Nuts, flats, and locks and you’re good to go. Nylon locknuts work well, but will slow you down and aren’t necessary.

29. Booster and master cylinder installation calls for attention to detail. First, connect the pedal, brake light switch, and push-rod under the dash using new bushings. Put a dab of white grease on the power booster push-rod tip and seat the master cylinder. Adjust the rod tip in or out so it “just touches” the master cylinder piston, which will be visible in the grease. If there is any master cylinder piston depression, the brakes will not release. If there’s too much depression, fluid can’t get into the bore, making it impossible to bleed the brakes. By the same token, you don’t want a gap between the power booster rod tip and master cylinder piston, which will cause too much pedal travel.

30. This adjustable proportioning valve goes between the smaller front master cylinder reservoir and your rear drum brakes. Gil installs it close to the master cylinder for easy access. And remember, fluid flow is regulated one way only, hence the “IN” and “OUT” markings. Again, front reservoir to rear brakes and the larger rear reservoir to front disc brakes via the brass distribution block.