My 15-year-old son replaced the bulb for my rear turn signal on my 2011 Buick Enclave. He researched it on the Internet, completed it in a timely manner and cleaned up after himself. He wants to be paid $35 for this work. His father, an economist, thinks he needs to justify this fee. I think this is a good question for you. And by the way, what would you charge to replace this bulb?

Well, we have two prices. If it’s a regular customer of ours, we’ll do it for nothing; it’s just a service we provide to our regulars. They can stop in and get little things like that taken care of. We figure we’ll have a chance to make it up when we gouge them for a transmission rebuild someday.

I guess your son doesn’t see you as a potential long-term customer!

If someone comes in and they’re not a regular customer, we’d probably charge $35 or $40. The bulb itself probably is five or six bucks, and it’s a 10-minute job for someone who’s done it a thousand times. But we have to pay for rent, tools, salaries and benefits, not to mention the bad coffee in the waiting room.

But your kid is a freelancer. He has no expenses. He probably used your tools. And your Internet service to do the research. So his rate should be lower.

And he’s charging you for his education, too. You’re paying him to learn how to do this. Remind him that in about three years, he may be looking to you to contribute a very large sum toward his educational expenses. So he may want to cut you a “good customer” break this time.

Tell him you’ll give him 20 bucks. And mention that if he doesn’t moan and groan too much, also throw in his continued free room and board for now. And Internet.

I had my 2002 Lexus’ tires rotated at the dealer. They inspected my brakes and told me that the front left was only a 2, but all the other pads/brakes (right front, both rear) were fine, at 7. So I took my car to another garage to see if I could get a better price on the front brake job. They did a full brake inspection and told me that not only did I need front brakes, but I needed rear brakes as well, since all of my pads were at 3. Very confusing. So I went back to the dealer. He had a different mechanic inspect the car. This second mechanic told me that yes, the front brakes should be replaced (which I knew) ... and then told me that my left rear pads were a 4, and my right rear were a 7. How can there be such discrepancies between the two garages concerning the measurements of my rear brake pads? I had only the front brakes fixed. Should I have done the rear, too? The dealer told me I probably could wait another 10,000 miles before doing the rear brakes.

The reason the numbers can be different is because they’re all subjective. For instance, some girl on the beach might have seen my brother back in the day and said, “He’s a 10.” Actually, that’s a bad example. No one ever said that. Only twice in his life did he ever get a rating as high as a one-and-a-half. And he married both of those girls. But you get the idea.

The numbers represent the amount of life left on the brake pads. But they’re just estimates, made by a mechanic who uses his eyeballs, not the Hubble Space Telescope.

So a 5 means the mechanic estimates you’ve got about 50 percent of the pads’ life left. In which case, there’s no need to replace them. Whereas if you’re at a 1 or 2, meaning you have 10 percent to 20 percent of pad life left, that means it’s time to replace the pads.

So your dealer was right that, since your front left was a 2, it was time to replace the front pads.

But what concerns me is the discrepancy between the front left and front right pads. If the left front was a 2 and the right front was a 7, that suggests to me that there’s something wrong with that left front brake.

Something is keeping that left front brake applied, even when your foot is off the brake pedal. It could be a sticking caliper piston, the pads sticking in the caliper bracket or a crimped brake line. But that needs to be checked out. Otherwise, those new pads on the left side will wear out too quickly, too.

So ask the dealer to take another look for you, and see if he has an explanation for why the left front wore out so much faster than the right front.

And even if he can’t come up with anything, when you go back to get the rear pads done in 10,000 miles, have them check the fronts again. And if the left is wearing faster than the right, insist that they do some more investigating.

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