Warped Discs
Here we go.
Years ago when I was still working in the garage, a customer called us up and said that a brake job we had done for him had gone awry.
We had done a brake job on his old Volvo, and we had put on new pads and new disc rotors, and it was all right for several months.
He says, "Gee, now when I step on the brakes, I get a rumbling. The harder I step on the brakes, the worse it is. In fact, I don't really feel it at low speeds or if I step on the brake gently, even at high speeds, but if I really lay onto the brakes, I feel that shuttering in the car. One of those new discs must be warped."
And I said, "I doubt it..."
Anyway, he brings the car in and we drive it around, and turns out, he is right. It is rumbling when you press on the brakes hard, which is a classic symptom of a warped disc. So we put the dial indicator on it, but it says there is nothing wrong with the disc.
So at that point, we check over the whole thing, because a bad tie rod or a crummy ball joint could also cause this vibration. We check over the whole thing. We find nothing wrong. But to make him happy, we put four new discs on, so he will be happy. We figure, maybe one of our intruments is off a bit, so for good measure, we put four new discs on the car.
We drive the car to check it out, and of course, the vibration is still there. It is not fixed.
We put it back on the lift. We dedicate one of our mechanics to this problem. So he works on it for a while. Then, he is standing right under the car, in the middle, with the car on the lift, wrench in hand, getting ready to remove something.
And I say to him, "What are you doing?"
He says, "This is it. I know what's wrong with it."
And the puzzler question is this.
What's he going to remove? And why does it fix it?
