This is one of the most difficult repairs we have done on Corvettes. One should allot two days for its undertaking. It requires a degree of patience and dexterity above that of most repairs. It is however a backoutable job, that is to say that once started one could leave the parking brake shoes off, reinstall the calipers and drive the car to a repair shop willing to do the job for you. Why so difficult, the factory assembled the brake shoes before installing the spindle. Since the spindle is pressed on, we are left with servicing the assembled unit. If you're considering changing the wheel bearing at the same time you would be well advised to have the whole job done by a specialist. If this is the case remove the trailing arm from the car and send or deliver it to the specialist along with the new brake parts. When pressed into place the bearing location is extremely critical, using .001" shims for proper placement. Over the years most rear wheel bearings replaced in our shop had been replaced improperly one to two years previously. On the other hand, when u-joints are replaced it is well advised to grease the bearings using the aftermarket greaser tool. We have yet to replace a wheel bearing that was well greased.
tools needed: You'll need a very good drop light, headlight spring
tool (illustrated 1.), 3/8" socket screw driver, needle nose pliers, very
small screw driver, dental floss, silicon sealant, a 3" cut-off wheel
(whizzer), and a homemade wire spring tool.
Begin by drilling out the 3/16" factory rivets securing rotor to hub (ill. 2). If rivets are missing the rotor has been serviced before. If rivets are present mark the rotor and hub such that relative positioning is maintained. This minimizes runout of the wheel and is why the factory riveted them originally. Remove caliper while keeping steel brake line attached. This will minimize the need for bleeding later. The factory recommends removal of the brake line to prevent damage to it. Your call, remember that each time a steel brake line is removed and reinstalled the flanges and seats experience wear.
Remove the upper connecting spring using the headlight spring tool (ill. 3). Next remove side springs using socket screw driver by pushing in and turing 1/4 turn. Spread both shoes apart from each other and remove.
Servicing the actuating lever is the most important part of this job and generally the most difficult. Note that when this assembly corrodes and seizes, use of parking brake causes the shoes to twist and jam the wheel, which in turn cause excess wear to the positraction clutches in the differential. We recommend replacing it with its stainless counterpart. If yours is free and you're tempted to leave it in place, at least grease it. This assembly cannot be removed as a unit. We use a 3" cut-off wheel (whizzer) to cut it in half (ill. 3). The new unit must be assembled in the car and is extremely difficult. Each of the two pieces is marked L or R for location to the proper side of the car (ill. 4). All references to left or right of a car are made from the drivers seat, that is with the driver looking forward. The instructions accompanying the stainless hardware explicitly diagram the orientation of both the actuating levers and adjuster sprockets (ill. 5). The lever is placed onto the wheel back plate first with the piece containing the pivot pin through the slot. The other half is then placed onto the pivot pin. With grease having been applied to both sides the pivot pin, the shaped washer and retainer clip placement are manageable. The retainer clip will start and stay in the pin groove because of the grease. Needle nose pliers are used to secure it properly. This work is done from the underside looking up (ill. 6).
Prepare for shoe installation by applying silicon to the shoe pin base and prop into position until silicon has dried. Pins should be at a slight out- ward angle and pulled out as much as possible (ill. 6). Compress at least the rear shoe retainer spring using dental floss string as shown (ill. 7).
Install the rear shoe with the upper long connecting spring attached. Place shoe spring and its retainer over the pin. Insert socket screw driver through the wheel hub access hole and onto spring retainer, push and turn 1/4 turn to secure. A properly secured pin will have its little flanges seated into grooves present in the spring washer-like retainer. Use a cigarette lighter to burn the string which will release spring tension and secure the brake shoe.
Install the front shoe and connect the upper connecting spring after the retainer spring has been installed. We use the headlight spring tool for installing the upper spring and the homade wire hook tool for installing the lower because the wire hook is thinner. Install the shoe retainer spring and washer like retainer. Check actuator lever to insure proper fit into brake shoe slots.
Attach one end of the lower connecting spring to a brake shoe. Grease adjuster sprocket threads and ends. Adjust sprocket all the way in, (turn clock- wise). Locate and orient adjuster sprocket with slotted end and sprocket toward rear of car for left side. Slotted end and sprocket favor the front of the car on the right side. (Illustrated on accompaning instructions with hardware kit) Attach the loose end of the lower connecting spring to the brake shoe, securing both shoes completely. Straight alignment tabs and install new park brake cable as necessary (ill. 9).
Adjusting the shoes is done in the same manner as regular old fashioned brake shoes using a screw driver instead of a brake spoon. Install the rotor and secure with at least three lug nuts for proper alignment and be sure to align access holes in the rotor with corresponding holes in hub. Remove any rivet remnants if present (ill. 10). Rotate rotor while looking in access hole for adjuster sprocket. Stick a medium sized screw driver into the access hole and pry the sprocket counter clockwise or have it unscrew itself from its threaded housing in a manner to stop the rotor from turning (about 15 - 20 clicks). Now ratchet the sprocket in the other direction about 8 clicks to properly neutralize the brake shoes. The rotor should free wheel. If there is any drag loosen it 2 or 3 more clicks. Although primitive in appearance this system works very well with positive results when exerting a reason- able amount of pressure by pulling on the actuator lever for testing. At this point if there are any problems with the functioning of the system when testing by hand the rotor must be removed and all components carefully inspected. Most problems are related to the actuating linkage.
the caliper. Many systems we have encountered are tight making
reinstallation of a caliper difficult. Here's a clue that always works
on the tough- est systems. Catch the bottom edges of the pads on both sides
of the rotor's outer surfaces. Use a piece of sheet metal as a prop if
necessary. Many auto parts stores sell such a tool, known as a brake pad
installation tool. The pads are now crooked are not likely to slide the
rest of the way down. Crack the brake bleeder screw loose while wiggling
and pushing the caliper downward. Works every time without applying
Proper bleeding sequence starts with the right rear
(furthest away from master cylinder), then left rear
then right front and finish with left front.
Proper bleeding sequence starts with the right rear (furthest away from master cylinder), then left rear then right front and finish with left front.
The completed job
Click image for large view
10. Flush grind rivet remains & adjust brake shoes