Tire Pressure Procedure

We all assume we know how to perform new, simple tasks, constructing a procedure in our minds before we start. And of course, we often have to revise that procedure once we start and discover what my friend Dan refers to as “the hidden bummer factor.”

My wife told me that a light on her dashboard indicated that a tire was low, and asked me to go out and fill it. I’ve completed this task a hundred times, but I remember the first time. I assumed that the procedure consisted of:

1. Drive to filling station.


2. Find out how much air to put in the tires.


3. Put quarters in the air machine.


4. Fill up tires.


5. Drive home.

But after the first trip, I had to modify the procedure, adding a new Step 1: “Bring quarters.”

To determine the tire pressure, I assumed that the tire would be the best source of this information. I tried reading the cryptic embossed codes on the side of the tire, then gave up and looked it up in the owner’s manual. The owner’s manual instructed me to look for a placard inside the driver’s side door jamb – an easy solution.

Once I fed the quarters into the air machine, I discovered that I had to remove the valve stem caps, which consumed time, so the air machine shut off before I was finished. This meant that I had to modify the procedure again, inserting a new step before putting in the quarters: “Remove valve stem caps.” And of course, I had to insert another step before driving home: “Replace valve stem caps.”

I now had a procedure that has served me well for a quarter of a century. When my wife asked me to fill her tire the other day, I gathered a handful of quarters and drove to the filling station. After glancing at the tire pressure placard, I dutifully walked around the car, removing all of the valve stem caps. I set them on top of the tire, so that I don’t kick them away or step on them as I hustle to fill the tires before the time runs out on the air machine.

Ready to complete the task, I walked up to the air machine and discovered that after all this time, I had to add a new step to the procedure. Taped to the air machine was a hand-written note: “Out of order.”