by Pat Goss
Corvettes are wonderful automobiles, but they do have some unique problems. Take mid-year Corvettes with four-wheel disc brakes through 1982. They used brake calipers that were fixed in position. So because the calipers couldn’t move, the pistons inside the calipers had to be able to move in different directions, up, down, sideways, where a normal piston just moves in and out.
Well, that led to a problem where sometimes after a long drive on the interstate, you’d hit the brake pedal and the pedal would go to the floor or nearly to the floor. Well, what caused that was too much run out in the brake rotors. As the rotors turned, they’d slap these pistons back and forth. That would cause the brake fluid to foam, or in some cases air to enter the brake system. Quite dangerous.
If you have that problem, make sure you check the run out on the rotors, using a dial indicator. Of course this portion would be touching the rotor and you’d rotate it, you take the measurement. The amount of run out must absolutely not exceed what the vehicle manufacturer allows.
All right, C5s. They’re highly computerized and they’re great cars, but if you’re going to do anything on them, you need good information. Now if you look in the aftermarket, you’re not going to find a manual for the C5. The manuals stop with the C4s. And even if you could find it, you look at those manuals and there is absolutely nothing there. A true C5 manual comes in three books. There’s a lot more there than there is in one of those universal ones. Also you could go online to sites like Alldata to get your information.
Now the big thing is with all of these computers spread all over the car, some of them are behind the right front wheel, some of them are in the floorboard, some of them are even in the trunk of the car, all of these are susceptible to moisture intrusion, and a lot of the warning lights and warnings in the information center can often be traced to moisture. So lots of times it’s a matter of following procedure, disconnecting the various computers that affect that warning, and simply plugging them back in. That cleans the contacts, the problem’s gone.
If you have a question or comment, write to me. The address is MotorWeek, Owings Mills, MD, 21117.