Despite the volumes written about the legendary prowess of '60s musclecars, the words always seem to gloss over some serious engineering shortcomings of the era. Brake packages were often, in a word, terrifying. One good shot was the most you got, if you were lucky. After that, it was white-knuckle time when it came to stopping in a hurry--and that was with a powerplant kicking out factory horsepower. Brake fade was the name of the game. Add a cam, some carb, headers, and exhaust, and stopping becomes even more elusive. While drum brakes are great for stopping lumbering buses and dump trucks, they're no good for gas-huffing musclecars.
The good news is that it's never been easier to upgrade your '60s- or '70s-era GM musclecar to a disc brake package. Stepping up to serious stopping power with disc brakes on all four corners is as easy as picking up the phone, calling Stainless Steel Brakes and Classic Tube, opening the boxes, and spending an afternoon under the car spinning wrenches. While upgrading the front brakes is usually a simple matter of a spindle swap, working out back requires removal of the rear axles in order to get down far enough to remove the drum-backing plates. The perfect time to upgrade is when you have to service the bearings, axles, or rear gears. It might be a good time to switch when you've pulled that brake drum off and find that gear oil has glazed your brake shoes like a day-old donut.
Upgrading or reconfiguring any stock braking system requires a methodical system approach, and attention to detail. Bolting up a brake kit, without taking into account the condition of the entire system from master cylinder to bleed screw, may be the last mistake you ever make. Spanking new calipers and rotors won't help if connected to ancient brake lines, spent fluid, and a spongy master cylinder. When upgrading to discs on the corners, don't forget to inspect and replace lines if required. Adding an adjustable proportioning valve while the hydraulic system is apart is also a good idea, and will allow for tuning of the front to rear braking ratio after everything is buttoned up. A life absent of unexpected sideways braking is always a good thing.
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Back the brakes all the way down to the backing plate. Remove the rear differential cover to drain the gear oil and to access the C-clips. Remove the C-clip cross-shaft retaining bolt. |
Push in the axle slightly, and turn the carrier over by hand to remove the C-clips; a magnet makes it easy. Remove the axles and be careful not to damage the seals. Remove the backing plates. |
Install the caliper mounting plate. Orient the plate according to the ultimate position of calipers. Cinch it down to the flange. |
Insert the bolts and spacers through the mounting plate. Mount and fasten the caliper-mounting bracket to the mounting plate. |
Torque all fasteners to recommended values. |
Load up the calipers on the bench. Tabs may need to be bent slightly for a proper fit. |
Slide the axle back in slowly and push in to allow reinstallation of C-clips, cross-shaft, and retaining bolt. |
Replace the C-clips. Line up the cross-shaft retaining bolt before pushing into place. Fasten the retaining bolt. |
Throw on the disc, and fit the caliper to line up the holes for the mounting bolts. |
Thread the mounting bolts through and cinch down the loaded caliper assembly. |
The stock brake hard line was shortened up for a more "sano" install of the braided stainless steel flexible line. |
Always use new copper washers when installing or replacing brake lines. The washers are designed to seal only once. |
Fasten up the flexible line to the hard line. Use line wrenches to prevent round bolts and excessive swearing. |
An adjustable proportioning valve is an indispensable item when it comes to getting the front to rear braking ratio dialed in. Double check all brake line fittings and mounting fasteners before adding brake fluid. Bleed system and check everything again. Now, enjoy your newfound braking power. |