All shark Corvettes have dual-reservoir master cylinders that, in effect, act as two independent braking systems. If the front brakes fail, the rears will still operate and vice versa. Obviously, this is a good thing. With age and use, the master cylinder will eventually wear out and will need replacement. Fortunately, this is a simple task that can be performed with basic hand tools. This procedure will also apply to any Corvette that uses this same basic master cylinder setup.
The first step is to evacuate the brake system of all its brake fluid. This is accomplished by opening a bleeder valve on one of the front wheels and positioning a catch basin beneath it to catch the brake fluid. Be sure to use a catch basin to contain the brake fluid as you bleed the system because the fluid will eat into the blacktop of your driveway or remove the paint from your garage floor if it gets on it. Next, open the hood and use a flat-blade screwdriver to pry the spring clamps that hold the cover and rubber gasket on the master cylinder. Go inside the car and pump the brake pedal, monitoring the front reservoir to see when it is completely empty.
Close the front bleeder valve and move the catch basin to a rear wheel. Open a bleeder and again pump the pedal until the rear reservoir is totally empty. Alternatively, you can purchase and use a trigger-operated vacuum tool that is easy to use and operate for draining fluid and bleeding air from the brake system. One of these tools will set you back about $50-$90. You may also be able to borrow one from AutoZone or another auto parts store if you purchase your brake parts there.
When all the fluid is out of both reservoirs of the master cylinder, the front and rear brake-line connectors can be loosened with an open-end wrench and pulled free of the master cylinder. if you happen to have a set of line wrenches available, by all means use them, as they will reduce the risk of rounding the corners of the connector nuts. A gear wrench or a ratchet with socket is then used to remove the two retaining nuts and lock washers that hold the master cylinder to the brake booster (or firewall if you don't have power brakes). When these nuts are off, the master cylinder can be pulled off the two mounting studs and removed from the engine compartment. You can take this opportunity to clean up and repaint your brake booster and rusted brake lines.