Quickest Discs

The Biscayne’s factory...        read full caption The Biscayne’s factory manual-drum system is glaringly devoid of technology. The single-chamber master cylinder pushes fluid through a single line into a distribution block (arrow). The block has three outlets; two supply pressure to each of the front wheel cylinders, and the third (toward the rear of the car) pressurizes the rear brakes. Yep, if this style of master cylinder goes south, you’re left with no hydraulic brake system. That’s a good enough reason to swap it out for the GM-style SSB dual-reservoir master, which has separate circuits for the front and rear brakes.

We drove up to Marlan’s...        read full caption We drove up to Marlan’s desert oasis and slid the ’65 into a vacant bay in his air-conditioned, six-car garage. We jacked up the Biscayne’s front end and removed the ancient hub and brake drum. Good riddance, we said.

Three bolts attach the backing...        read full caption Three bolts attach the backing plate to the spindle and steering arm. Two are below the spindle shaft and hold the steering arm in place, and the third holds the wheel cylinder in place. The third bolt was particularly stubborn—we couldn’t budge it, even with an extra-long box-end wrench. Marlan volunteered his manly 18-inch breaker bar for the task, but our lazy selves prefer power tools. Marlan’s high-torque impact wrench made very short work of the offending bolt without snapping our wrists clean off.

SSB supplies a trick set of...        read full caption SSB supplies a trick set of precision-machined brackets to accommodate the discs on the existing drum-brake spindle, so put away that pickle fork and sledge. There are two brackets per side—the caliper mounts on the large C-shaped bracket, and the smaller bracket sandwiches the steering arm and provides additional rigidity to the caliper bracket.

After fitting the brackets...        read full caption After fitting the brackets to the spindle, we realized that one of the provided Grade 8 bolts (in hand) was too long to thread into the forward-most mounting hole. Fortunately, the original steering-arm mounting bolts, also Grade 8, are the correct length, so we retrieved one from the parts pile and installed it. The lesson here: Don’t throw any old parts away until the installation is complete! We torqued all the bolts to SSB’s specs.

Voila—we converted a...        read full caption Voila—we converted a drum spindle to a disc spindle in five minutes, no Bridgeport required! We love it when bolt-on kits are truly bolt-ons.

We packed the SSB-supplied...        read full caption We packed the SSB-supplied Timken bearings with our special, err, hand-powered bearing packer, and installed the inner bearings on the inner race of the hub. Don’t follow our poor example—try to keep the rotors free of grease.

Installation of the grease...        read full caption Installation of the grease seals requires Kent-Moore J-22904 Seal Driver and a dead-blow hammer. Actually, we were just taking advantage of Marlan’s vast collection of specific-but-seldom-used tools. But using the right tools is a heck of a lot more enjoyable than tweaking the seal out of shape while trying to beat it in with a ball-peen hammer. Three whacks of the dead-blow and it was perfectly seated in the hub.

Slide the rotor on the spindle...        read full caption Slide the rotor on the spindle and install the outer wheel bearing, keyed washer, and castle nut. SSB’s supplied keyed washer didn’t fit on our spindle, so we reused the original washer. (Didn’t we already tell you not to throw any of the old parts away?) To seat the bearings, torque the castle nut to 12 lb-ft while spinning the rotor. Back off the nut until it’s just loose, and retighten it until you’re just able to install the cotter pin. Now is a good time to spray some brake cleaner on the rotor to ensure there’s no grease left behind.

We assembled the caliper by...        read full caption We assembled the caliper by installing the pads and antirattle clip (arrow). The new flexible line bolted right up to the caliper using a copper washer to seal each side of the banjo fitting. Note: This kit mounts the calipers ahead of the spindles as opposed to factory setups, which mount the calipers behind the spindles, so the calipers are reversed left and right. The “L” caliper now mounts on the passenger side, and the “R” caliper bolts up to the driver side. If in doubt, remember that the correct installation puts each bleeder screw at the top of the caliper.

Slide the caliper over the...        read full caption Slide the caliper over the rotor and torque the supplied 3/8-inch Allen-head mounting bolts to 25 lb-ft. Clip the end of the flexible line into the frame bracket, and bolt up the hard line.

We bench-bled the new master...        read full caption We bench-bled the new master cylinder by mounting the body in a vice and pushing on the piston with a socket extension. We called it good when we couldn’t see any more air bubbles in the lines of the included bleeding kit. Skipping this step virtually ensures that you won’t be able to bleed the system properly, so it’s important.

We found it easiest to pull...        read full caption We found it easiest to pull the brake-pedal clevis/pushrod assembly out of the car for the next step. We installed the tightly fitting rubber boot over the pushrod, and then pulled the boot over the back of the master cylinder.

Prior to the wrenching session,...        read full caption Prior to the wrenching session, we cheated a little and mocked up the new lines on another, fenderless ’65 (see, there’s a good reason we’re keeping this semi-stripped hulk in the garage!) to show what’s involved. The front reservoir line screws into the top of the factory distribution block (via an adapter) where the original single master cylinder line resided. The factory rear brake line is removed from the distribution block, and that port is plugged. The rear line needed to be re-bent upward to screw into the supplied proportioning valve, which allows precise tuning of the rear brake bias. We’ll call this swap as bolt-on as it gets, with no cutting or flaring required. However, we did need to buy the 3/16-inch plug and a 3/16-to-7/16–inch adapter fitting.

One big problem kept this...        read full caption One big problem kept this from being the slam-dunk swap we expected: The disc hubs move the wheel mounting planes outward relative to the factory drum hubs, widening the front track by about 1-1/2 inches. To make a long story short, our 15x8 Corvette Rallys with P255/60R15s took a liking to the wheel lips and made turning impossible. We borrowed some stylish rolling stock from Marlan’s Trans Am to get the car home—and while they fit a little better, they still contacted the front of the wheel opening on turns. We’re bummed that we can’t keep our tire-and-wheel combo, but we were able to fit a stock 15x7 wheel with 4-1/2-inch backspacing to solve the problem. The set cost $20 at a local junkyard, and we remounted our original tires. We actually prefer the dog-dish hubcap look, so we’ll change out the rear wheels to match.

Anyone who thinks four-wheel manual drum brakes are “good enough” for his car must have never driven it in Los Angeles. Sure, Southern California is an old-car mecca, but traversing the overcrowded freeways crawling with half-baked drivers puts our old iron at the brink of disaster every time we turn onto an entrance ramp. What’s a car crafter to do?

Avoidance is key. Like your first ski trip, urban driving is a dicey, unpredictable situation until you learn to safely stop yourself. Likewise, we figure Honda CRX and Ford Focus drivers must feel like bowling pins when our ’65 Biscayne comes creeping up from behind, so we decided it was time to call up Year One and order a Stainless Steel Brakes disc-brake conversion kit for the bulbous B-body. At $579, it’s a serious bargain. It’s an especially easy swap, because it reuses the factory drum-brake spindles—so there’s no need to break the ball joints or steering linkage loose. Swapping to discs won’t alleviate the nervous feeling that econobox drivers get when the ’65 is out on the prowl, but we like it that way. As long as we know we can scrub off our speed, we can live with our intimidating presence and continue to educate lesser vehicles on what’s really “fast and furious.”