Mountains of Trouble
It is time for the new puzzler. This one is an old one. Like, really old.
Many, many years ago we had a customer come into the shop. He was having a peculiar problem with his brakes. So from time to time, he would lose the brakes, meaning he would step on the pedal and it would sink to the floor.
Then, if he pumped the brakes like crazy, or if he just got lucky, the brakes would return. If he managed to pull over without crashing and waited for a while, the brakes would be okay.
So, the first time it happened, he was in the White Mountains of New Hampshire traveling up and down the mountain roads. It was really scary, so he pulled into a local shop and they couldn't find anything wrong with the brakes at all. So he continued his journey.
A little while later, an hour into the trip, it happened again. He pulled it into another shop which was a little more enterprising. They replaced the calipers, pads, the master cylinder, the power booster, all of the wheel cylinders, all the brake lines...They replaced everything.
So he leaves. And of course, a few hours later, the problem returns. So, the guy brings the car into our shop. We go over it. Everything is new, so we look at it thinking, it must be something else. We go over the whole car, and we can find nothing wrong. The guy takes it to a couple of other shops, and they can also find nothing wrong with it.
Months go by. He comes back in for just routine maintenance and he mentions that if he drives the car around town, the brake issue is never a problem. It was only a problem when he went on these extended trips and was in the mountains.
We do the oil and filter change. We also discovered that his water pump was leaking. We replaced the water pump. And he tells us it is a little loud, so maybe there is a hole in the muffler. And there is, so we replace the muffler and the tailpipe, basically his exhaust system.
And after that, the original problem with the brakes was fixed!
So, which one of those things fixed his original problem?
Good luck.