Corvette Fever Homepage Corvette Fever
Get Adobe Flash player

Braking Away: Upgrading the disc brakes on a 68-82 C3 Corvette

By Chris Petris
Photography by Chris Petris, Hope Petris
Chevrolet Corvette C3 Rivets
PSA had the rotors replaced at least once before, so we didn't have todrill out the rivets to remove the rotors. Be sure there are no burrs ordings in the hub, preventing the rotor from sitting flat against thehub. Sometimes, when the rivets are pushed out for rotor removal, highspots occur around the rivet hole causing the rotor to sit at an angle.We use a small sander to knock down any obvious high spots.
Chevrolet Corvette C3 Hubs
We slid the rotors over the freshly packed wheel bearing hubs for therunout check. The rotor should have a maximum of .004 runout during onefull revolution of the rotor. This runout figure holds especially truewith conventional calipers. Be sure to turn the lug nuts over andtighten all five for a true runout reading.
Chevrolet Corvette C3 High Spot
Boy, did we have a high spot! After cleaning the hub, you can see we had.010 runout. If we find a high spot, we mark the rotor and the stud atthe highest point and record the figure. There is a good chance we willfind a problem considering the age and abuse the hubs take. The rotorsand hubs can be assembled, torqued, and then machined as an assembly toeliminate runout, but you would already be removing material from therotors surface.
Chevrolet Corvette C3 Rotor
First, we try changing the position of the rotor on the hub to alleviatea high spot. You have four chances to make it better. Sometimes thisprocess helps, and sometimes it makes the runout worse. We also trychanging the rotors from one side to the other if possible. With ourdirectional SSBC Turbo-slotted rotors, we didnt have that luxury. Youcant change the position of rear rotors on the hubs because of thedrilled holes for emergency brake adjustment unless you want to removethe rotors for brake adjustment.
Chevrolet Corvette C3 Spindle
We've been using brass shim material in .005 increments from ACEhardware for shimming. We place a shim between the rotor and hubassembly opposite the high spot. Remember, the high spot will also belower when a .005 shim is placed on the low spot. We also found thatmoving the shim on either side of the high spot sometimes is required.Be patient, this procedure can be very aggravating at times.
Chevrolet Corvette C3 Reading
Now that we're happy with our final runout reading, we record the finalrunout reading on the rotor and mark where our shim is placed. Thecorresponding stud is also marked so the rotor can be reinstalled in theproper location. We're very pleased with the .002 final reading.Excessive runout can be heard when you're riding next to a wall. Therhythmic squeaking would be telling you that the rotors aren't parallel.
Chevrolet Corvette C3 Caliper Mount
Once you're satisfied with the rotor runout, the calipers go on next.The SSBC calipers may require shimming to center the caliperside-to-side over the rotor. This is important for even disc-pad wear.Also, improper shimming can bind the caliper pistons. We found thatstarting the caliper mounting bolt opposite the side that requires theshims makes shim installation easier. Here, the lower mounting point ofthe driver-side front caliper needed shims. We used the K&S Brass Shimmaterial PN 250 (.005X4X10) from Ace Hardware.
Chevrolet Corvette C3 Pads
The disc pads slide in place like the original calipers except that twopins hold them in position. If the shimming was done properly, the discpads should drop in place. No hammer is necessary. The rotors shouldturn freely if the shimming is correct.
Chevrolet Corvette C3 Clip
The supplied antirattle clip is caught under the rear disc-pad retainingpin and then it hooks under the front pin. These antirattle clips workwell without binding the pads like some of the aftermarket clips thatwere used on the OE calipers.
Chevrolet Corvette C3 Caliper And Rotor
All that's left to do is to install the S/S braided hoses and bleed thesystem. Now's the time to go around and check all the calipers for theproper mounting bolt torque of 65 lb-ft and proper pad clearance onemore time.
Chevrolet Corvette C3 Line Fitting
We used a line wrench to loosen and tighten the 3/8-inch line fittingwhile holding the hose with an 1116-inch wrench. If you have troubleremoving the line fitting nut, cut the old hose off and apply heat witha torch on the hose fitting. This process works well and keeps thefitting in good shape. Make sure you cut the old rubber hose so it canbreathe or it will blow off at high speed.
Chevrolet Corvette C3 Bent Hose
We found the hoses needed to be at a 45-degree angle at the caliper forproper clearance. One thing to pay close attention to is the possiblepinch-point between the steering arm and the control arm when the wheelsare turned lock to lock. Be sure to check the hose position when yourCorvette is at ride height during full lock-to-lock turns.
Chevrolet Corvette C3 Bleeding Brakes
Now it's time to bleed the brakes. We use a pressurized reservoir topush the silicone brake fluid to each caliper. Start with the right rearcaliper, then the left rear caliper, then go to the front of the car.Bleed the front right caliper and then the left caliper. The pedalshould have two to three inches of travel in the beginning. As the discpads seat, the brake pedal should raise slightly.
Chevrolet Corvette C3 Installed Caliper
The SSBC caliper looks great between the SLP five-spoke wheels. We werethinking the calipers should be red, but they look good as is, blendingwell with the wheel. We are thinking about red for the lettering,possibly to show the caliper off with a little style.
Chevrolet Corvette C3 Wheel
The front wheels should now be torqued properly to 95 lb-ft, promotinglong wheel and rotor life. Slamming the lugs down with an impact wrenchcan damage the hubs and rotors, causing rotor runout concerns. It wouldbe a shame to spend the time getting the rotor runout withinspecification and then hammering the wheels on.
Stainless Steel Brake Corporation
11470 Main Rd., Dept. VM
Clarence
NY  14031
Ace Hardware
www.AceHardware.com

Chevy Corvette Research
Chevy Corvette When looking for your next vehicle, think about the Chevy Corvette, a stylish car with nice features. The 2009 Corvette is offered with your choice of V8 engine. It has had 0 vehicle recalls, which can give you an idea about its reliability. Also check out the Chevy Malibu.
 
1968 Chevrolet Corvette - Motion's Mail-Order Masterpiece
We check out Jamie Jarvis' roll-your-own Phase III 1968 Motion Corvette... more
 
1957 Chevrolet Corvette Convertible Hard Top - King Of The Hill
Chip Travis' fully restored 1957 Chevrolet Corvette... more
 
1972 Chevrolet Corvette - Top Flight Flyer
Charlie Carr's '72 LT-1 was a key part of the second-coming of the high-performance small-block V8... more
 
1987 Chevrolet Corvette Project Car - Project C4orce Launched!
Here is a look at our recently acquired 1987 Chevrolet Corvette to start off Project C4orce... more
 
Chevrolet Corvette C2 - The Timber Wolf C2 Gets Suspended
The Chassis, Suspension, Brakes, And Rearend Get Installed... more
 
1975 Chevrolet Corvette Race Car - Fast Line Around The Learning Curve
Take a look back at John Greenwood's Outrageous C3 Corvette Racer... more
 
LS7-powered 1961 Chevrolet Corvette - Total Transformation
No concours Corvettes were harmed in the making of Larry Allman's incredible, radical '61 Vette-Rod... more
 
2005 Chevrolet Corvette - A Blatant Offense
We check out a wicked, supercharged 2005 Corvette convertible... more
 
1966 Chevrolet Corvette C2 - Godzilla Lives
A slick '66 running 12-second e.t.'s while still looking stock... more
 
1961 Chevrolet Corvette - Z Whiz
Bill Sefton's 1961 Chevrolet Corvette roadster is a C1 restomod powered by an LT5 engine... more