RAY: Here's the answer. What was wrong is that he had a loose power steering belt.
TOM: Let me say it. What would power steering belts have to do with losing your brakes, Doctor? Funny you should ask!
RAY: Well, glad that you asked. Actually some of the other cars that GM makes, and not just GM, but other cars that have had this configuration -- have instead of a vacuum or a vacuum powered booster that is operated by engine vacuum, they have a power brake that is operated by hydraulic pressure. Where do you think this power pressure comes from? The same pump that runs the power steering.
TOM: You don't say!
RAY: And what was happening with this fellow is that when he went through a puddle, is that the belt, which was loose, would begin to slip. And what he would lose would be his power brakes. He would lose the power brakes and step on the brake, the pedal would feel very hard, but the car would not stop. And it felt to him like the cars of yesteryear when the brakes were wet and you'd step on the pedal it would feel hard, but the car wouldn't stop because the water was actually reducing the friction between the linings and the drums, or the disks.
TOM: And he no longer had power brakes.
RAY: All he knew was that there was something wrong with the brakes because the car wouldn't stop. When he mentioned that of course that he was losing his power steering, I said, "Ah hah! -- the belt must be slipping." And what we did was tighten the belt. And that fixed the whole thing.
[ Car Talk Puzzler ]