There's no question the superiority of disc brakes versus drum brakes when it comes to stopping. It would probably surprise most, though, how many classic Chevys are still rolling on outdated front drum brakes. Why would anyone still be using the old binders? There's no one real reason, but it varies from cost, to frugality, to some people are just fine with using them. We'll leave the stock resto cars out of the discussion, since it's obvious why they still have their factory drums.
It used to be that retrofitting discs onto an older car meant scouring the junkyards for '70s disc brake cars to rob them of spindles, calipers, master cylinders, etc. Well, in 2014 we don't have to do that anymore. Thanks to companies like Classic Performance Products (CPP), installing disc brakes on a vintage Bow Tie is easier than ever, and surprisingly economical.
Our Auto Metal Direct '67 Chevelle was restored fairly close to factory spec, meaning it had power front drums when finished. With our plan to really start driving this A-body and testing different parts on it, the front brakes definitely needed an upgrade. Whether you're drag racing, autocrossing, or just trying to survive on today's fast-paced/overcrowded roads (overrun with distracted drivers), you'll want to make sure you have plenty of stopping power. CPP's catalog gave us many options, from multi-piston disc brakes to proven single piston designs. They even have a kit to convert your Chevelle to front C5 Corvette brakes.
We went with front disc kit 67CBK-S. It's a complete package that includes the correct master cylinder, flex hoses, and even hard lines for converting to discs. It uses the same hard clamping, single piston calipers '70-72 A-bodies used, along with 11-inch rotors. Best of all, it prices out at $699, a real bargain when you consider it includes new spindles and calipers—it's truly complete. No need to hunt down junkyard parts, and everything is brand new. Best of all, CPP offers its brake kits in assembled form, to save the installer even more time during the conversion.
To further the safety issue while at the same time improving handling and driveability, we put in a call to Coker for a set of correct factory Rallye rims and handsome BF Goodrich Redline radial tires. The radials will not only help the car turn and ride better, but they'll also help it stop in a shorter distance. As for the Rallys vs the painted steelies with poverty caps we had, it is a matter of preference, but the former was standard on the SS and were needed to clear the disc brakes.
Follow along and we'll show you how easy it really is to give your car discs in a day.
|67CBK-S Complete Disc Brake Kit $699.00
|Coker Redline Radials
|Coker Reproduction Corvette Rallye Wheels
1 Our CPP brake kit came preassembled, with the rotors and calipers already mounted on the new spindles. CPP also includes new dust caps, and the peripheral small parts necessary for the install.
2 Here's what we started with: factory, 40-year-old drum brakes. Disc brakes were optional on '67 Chevelles from the factory, utilizing the Kelsey-Hayes twin-piston caliper.
3 The first step was removing the cotter pins from the upper and lower ball joint nuts, loosening the nuts, then hitting the spindle mount a few times with a heavy hammer to break it loose from the ball joints. Our car's joints are brand new, but if yours are high mileage units, now would probably be a good time to replace them. CPP sells new ones, part nos. FA487 (upper) and FA993 (lower).
4 After breaking the ball joints loose from the spindle, we removed the whole drum assembly.
5 The steering arm mounting bolts for the disc brakes are bigger than the factory drum mounting bolts. Word of advice: Remove the steering arms from the drum assembly before you remove the assembly from the car. It makes things a lot easier. Using a half-inch drill bit, we drilled the holes out on our steering arms so the new bolts would fit.
With that done, the new disc assembly is set in place on the control arms.
7 Then we tightened the castle nuts up on the ball joints, and installed new cotter pins, included with the CPP kit.
8 To mount the steering arms on the brake assembly, you have to remove the caliper and rotor to get access to the bolts.
9 With the brakes themselves installed, it was time to work on the hydraulics. First up was removing the old drum master cylinder.
10 Out comes the old master cylinder, and drum proportioning valve. The CPP kit comes with a new 11-inch factory power booster already attached to the master cylinder. Since our car already had power brakes, we didn't need to remove the booster, since both are the same.
11 Our system already had a long-rod booster in it. If yours is a short-rod, the CPP kit comes with the adapter/extender so you won't have any problems.
12 Before mounting the master cylinder, we attached the new front disc/rear drum calibrated proportioning valve. For drum brakes, the valve is mounted down low by the frame. For discs, it's mounted up near the master cylinder. This is why the kit includes new, pre-bent hard lines.
13 The new master bolts right up to our existing power booster.
14 Next, we pulled out all our old drum brake hard lines.
15 Then installed our new disc hard lines. You might have to bend the new lines a little to get them lined up properly, but that's normal.
16 Next up was this big line that runs from the driver's side all the way over to the passenger side. We unbent the line, then followed the factory routing to run it over to the right side flex hose.
17 The passenger side line hooks into the front of the proportioning valve. Again, you might have to bend this one a little for it to line up.
18 Here's where the long line hooks into on the passenger side.
19 Using the bleeder kit included with the master cylinder, we bled the master out first.
20 After the master was bled, we hooked the lines up, and bled the brakes at all four corners.
21 Here's how our finished system looks. We now have great stopping power that'll let us really push the car to its limits in testing.
22 The CPP disc kit wouldn't work with our factory 14-inch steel wheels, so we called our friends at Coker Tire and ordered up a set of 15x7-inch Rallye wheels in silver powder coat, with disc brake center caps, wrapped in Coker/BFG redline 225/70 radials. It was amazing the difference the Rallye wheels made in the car's appearance. And the Coker BF Goodrich Redline radials not only give us a classic factory look, but also the driving and handling benefits of a modern radial tire. We can't wait to hit the street!