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Third-Gen F-Body Z06 Corvette Brakes - Z(06)28

Killer Third-Gen Stopping Power On The Cheap!

Paul Riccioli Jr. Mar 1, 2006

It is a well-known fact that the Third-Generation F-Bodies were solid all around performers from the factory over their 11-year run. It is also a well known fact that while they were some of the best accelerating, best handling, and best braking cars on the street in the '80s and '90s, their technology has begun to pale in comparison to that of today's high-tech rides. The aftermarket has stepped up with a bin of go-fast, turn-quick, stop-short goodies that run from mild to wild and everything in between for these cars. While admittedly most people want to go faster and turn better, often, improved braking is dangerously neglected. The aftermarket has designed a number of combinations to help haul your Third-Gen down to a stop quicker than the factory system ever could. Third-Generation cars came from the factory with either a front disc/rear drum setup or four wheel disc brakes. While both setups worked well when new, over 20 years in advancements have rendered them near obsolete. The original hydraulic system suffers from spongy pedals, small single piston calipers, small rotor diameters, and brake fade. Any of the aftermarket front disc setups will outperform the stock GM pieces handily, however some carry a price tag near $1,000 or more. For around $500, and with some savvy shopping, and maybe some help from a few machinist friends, you can upgrade your Third-Gen F-body with a much newer, more technologically advanced factory braking system. The C5 Corvette Z06 front brake setup uses a larger 12.75-inch rotor that comes in a slotted and drilled version as well as set of dual piston calipers which feature a much larger swept area than the stock Third-Gen brakes. Combine these parts with a set of braided-steel brake lines and your F-body has just as much whoa as it does go for less cost than an aftermarket kit. Installation of this setup is simple with only a few hang-ups to slow you down. The toughest part is begging a friend to perform the machine work for you for free to help you keep the cost down. Even if you have to pay for all the work you can still keep your price below $700.

The most stressful part of the swap is modifying the stock spindles. Unfortunately, if you screw this up you'll be scouring the local junkyard for a new spindle and pulling apart your front suspension to replace the ruined spindle. Follow the diagrams for making the proper cuts on the spindle and always cut less off if you are unsure. You can always remove more later when you test fit and do your final cleanup work with a grinder. Also be sure to use a sharp drill bit and tap when you are making the caliper bracket mounting holes in the spindle. If you screw it up there's a chance you can go with a slightly larger bolt, however, removing too much material will compromise the integrity of your spindle.

Remove the factory calipers, brake hoses, rotors, bearings, and dust shields.

Remove the factory wheel studs and replace with the longer studs. (See Picture)

Have a machine shop machine the factory rotors down to hubs that will fit inside the new slotted/drilled rotors. They should just fit inside the new rotors. (See Picture)

Also have a machine shop make the custom caliper mounting brackets necessary for the C5 caliper assembly. (See attached diagram with specs and picture.)

Cut the ears off of the factory spindles as noted. (See Pictures) I used a hacksaw as this offered me the cleanest cut and the most accuracy. I wouldn't suggest using a grinder because if you mess up you'll be buying new spindles.

The two dust shield bolt holes near where you made your cuts must be drilled and tapped now. I used 1/2-inchx20x1.25 bolts here. You must use a drill bit sized 29/64 inches for the hole. Once again, be very careful here. Start with a smaller drill bit and work your way up using a lot of WD-40 or other lubricant. Be very careful not to wiggle the bit at all as this will open the hole too much and you won't be able to tap it. Be sure to tap the holes straight. This is another step you only get one shot at and don't want to screw up. Many people remove the spindles and use a drill press for this process. (I didn't want to take the chance of ruining my ball joints.)

Most people don't do this, but I cut my dust shields to fit back onto the car. I cut the two ears off of the bolt holes that were modified so that the shield is only held on with one bolt now. If this becomes a problem in the future I will remove them.

Clean all of the metal shavings off of your spindle and surrounding areas. Test fit your custom caliper bracket onto the modified spindle using the 1/2-inchx20x1.25-inch bolts. You may have to clearance the spindle a little bit using a dremel tool to get the bracket to sit correctly. Be careful not to get too close to the bolt holes.

Clean up any new metal shavings. Bolt the caliper brackets to the spindles using the 1/2-inchx20x1.25-inch bolts. I used blue Loctite to keep them from coming loose. Pack the new wheel bearings with grease and install them into your machined hub. Replace the rear seal. Install the hub onto the spindle assembly and tighten the nut to spec. Wash the new C5-slotted and cross-drilled rotors off with dish soap and water to prevent squealing. Install the rotor onto the hub assembly and use a lug nut to keep it snug for now.

Attach the caliper abutments using the 14x2.0x35mm Allen head bolts. You may have to do some more clearancing to make them fit correctly as well. With the abutment in place, check the spacing of the rotor between the abutment. It should be even, if not, use a flat file to remove part of the bolt boss on the backside of the abutment. Go slowly and be sure to use a file to keep from ruining the threads in the abutment. Once you have the spacing correct, bolt the abutment on for good using blue Loctite once again. Install the anti-rattle clips and the pads into the abutments. Attach the caliper to the abutment, being sure to grease the pins and use a dab of red Loctite on the caliper bolts. Install the braided stainless steel brake hoses using the C5 caliper banjo bolts. These brake hoses are made to fit the Third-Gen F-bodies with the 1LE braking package. Bleed the brakes out on both sides. Reinstall the wheels, and you're ready to go.

Some people have changed their master cylinder and brake-proportioning valve, however, my stock pieces have been fine thus far. For road racing applications, you may want an adjustable prop valve. The improvement in braking is realized immediately the first time you hit the pedal. The feel is much firmer and more confident compared to the stock F-body pieces. The Z06 brakes bring the car to a stop in a much shorter distance with ease. They are civilized on normal stops and the bite is immense when you get more aggressive with the pedal. There is no pull evident on gradual or hard stops with this setup. The only gremlin we have found in this system so far is that the increased clamping force causes the car to nose dive a bit on hard braking. An adjustable proportioning valve and some testing would most likely remedy this, however, for daily driving the problem is almost undetectable. For the track it would be recommended to adjust the bias to minimize the forward weight transfer. This setup was tested on a car with rear drum brakes and dive may be less apparent on a four-wheel disc car. One last option for those looking for an even firmer pedal that requires less effort would be upgrading to a smaller bore master cylinder, with one from a C4 Corvette being the best candidate. Overall the cost versus the return of this upgrade makes it a very attractive alternative to higher-priced aftermarket front brake kits.

Special thanks go out to Frank at F&A Machine in Middlesex, New Jersey for all of his help with the machine work, and the members of for all of their work in developing this swap.



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