Corvette Forum Project C4 Part 2: How to Install C4 Brakes

A minor detour on our road to the paint booth pays big dividends in braking performance.

On the first installment of Project C4, I replaced the leaking brake master cylinder with one from my low-mileage parts car. For the next step, it seemed only natural to address the rest of the worn braking system and give it the attention it deserves.

The stock brakes on early C4 Corvettes don’t have the greatest reputation for performance. Since I was replacing components anyway, I decided to perform a couple of affordable upgrades to improve the system without spending huge money on a big brake kit.

Corvette Forum sponsor KNS Brakes sent me a set of Hawk HPS brake pads to help the cause. Hawk states that these high-performance street pads are designed to offer improved performance with reduced fade with the added benefit of minimal brake dust. Look for a full review soon.

I also purchased a set of braided stainless-steel brake hoses. These expand far less than stock rubber brake hoses under hard braking. The result is improved stopping power and a firmer pedal feel.

Rounding out the brake parts is a set of AC Delco coated brake rotors. I also used the 34,000-mile calipers from my parts car. With about a third as many miles as my project car, these calipers have far less wear and tear on the pistons and seals.

Prep & Paint

Once I removed the calipers from the parts car, I cleaned them as best I could before painting them with aluminum silver brake caliper paint. The calipers will look stock, but won’t be susceptible to the powdery white oxidation of natural aluminum.

After the calipers were painted, I used a toaster oven to cure the paint per the paint manufacturer’s recommendation. I have a dedicated oven for this purpose — don’t ever use an oven you prepare food in to cure paint.

While removing the old brakes from the project car, I discovered that all of the brake pads had been installed incorrectly. The wire spring clips on each pad were placed outside of the caliper’s inspection hole, instead of compressed inside the caliper where they belong. Combined with the leaking master cylinder, I’m sure this contributed to my Corvette’s poor braking performance.

Once everything was removed, it seemed a waste to install shiny new components inside of a messy, dirty wheel well. I scrubbed the fenderwells and suspension with degreaser and used a pressure washer to get everything clean. The aluminum suspension components of these cars sure look handsome when they aren’t covered in a quarter-inch of grease!

An unusual feature of early C4 Corvettes is the fact that the brake rotors are the same diameter front and rear. The front rotor hats are domed, while the rears are flat to accommodate the parking brake.

Initially, I made a slight mistake during re-assembly, installing the rear rotors on the front. I didn’t realize this mistake until after I had completed the front brakes and began working on the rear, but fixing my mistake just meant unbolting the caliper and swapping rotors.

Installation

Once you’ve placed your new rotor on the studs, it’s time to re-install your caliper bracket. Make sure you have these bolts torqued down tight — you really don’t want this coming loose.

Next, re-install the rubber boots on your slide pins, grease them up with the packet supplied with your new pads, and slide them into the bracket. Make sure your boots are seated on both the pins and the bracket.

The next step is to use a brake caliper piston tool to fully compress the piston. Place the inner pad in the caliper and tighten down the tool until the piston is fully compressed.

Next, place your pads on the bracket. Pay careful attention to the orientation of the pads, making sure you are installing them correctly.

After that, I like to thread the lower bolt through the caliper itself into the slide so that the caliper can hinge into place. Make sure that the springs on the pads don’t pop out of the caliper when you do this. Remember, they belong on the inside!

On the fronts, I ran into some clearance issues with the pads, so I removed the outer anti-rattle clip on each side so that the caliper would slide into place. I’m going to hold onto these clips in case my brakes start getting noisy. When I take everything back apart to work on the suspension, I will probably re-install these clips when some pad material has worn down. So far, so good, though — no noise.

Use a 17mm wrench to hold your slides in place while you tighten your caliper bolts with a 15mm socket. Don’t forget to re-install your bleeder screw. Be careful not to over-tighten it and snap it off.

Installing the New Lines

The last step is installing the new stainless brake hose. This takes a little finesse, and it’s arguably the most crucial part of the install, so pay close attention and take your time.

I like to get the threads started on the metal brake line, then clock the line in place where it meets the caliper. Place a washer on the banjo bolt, push it through the fitting, and then place another washer on the other side. Thread the banjo bolt into your caliper, and make sure those washers are seated correctly.

Once everything looks good on the caliper side, tighten the brake fitting to the other end of the hose. Make sure it’s still at a good angle to the caliper. Then, you can re-install the retaining clip. I like to use a rubber mallet.

As a finishing touch, I installed some split loom over the sensor wires, since most of the original insulation had long since dry rotted and fallen off. This will protect the wires underneath, and it looks nice, too.

Bleeding & Bedding

With everything bolted down tight, I set about bleeding the brakes. Refill the reservoir, and get yourself an appropriate-sized flare nut wrench for the bleeder screws. You’ll also need an empty bottle, a hose, and a friend.

I enlisted my neighbor John to help me out. It was an easy job for him. He just had to sit inside and pump the brakes while I bled each corner of the Corvette.

Three pumps, hold the pedal down, and crack the bleeder. Since the brake system had been fully opened, there was a lot of air in the system. We had to repeat the process several times at each wheel to get all of the air bubbles out. This also allowed us to flush out every last trace of old brake fluid from the lines.

With the system bled, the pedal felt much better. Instead of going to the floor, it only moved an inch or so. The final step in the process is properly bedding in your pads and rotors.

Like a fresh engine build, it’s important to break in your new brake pads and rotors. You want the parts to mate to each other. Each manufacturer is different. Hawk wanted me to perform 6 to 10 complete stops from 30-35 MPH, then 2 or 3 complete stops from 40-45 MPH. After that, let the brakes cool for 15 minutes, and you’re done!

I’ll be publishing a full review of the Hawk HPS brake pads soon. For now, I’ll just tell you that they’re awesome. If you want to snag a set for yourself, head on over to KNS Brakes and tell them that the guy with the mullet sent you. Be sure to watch the full installation video below!

Video Shot & Edited by Jeremy Bryner, Downforce Media

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